Mako Attack

New Layout

2010-06-15T12:02:00.000-07:00

Made some tweaks to the layout, including blog search bar and some cool links on right margin. Open to any constructive feedback- any thoughts are appreciated. Thnx
Mike

Backin it up

2010-06-11T10:37:00.000-07:00

Installment 39 of a classic Mako Restoration

As stiff as those gunnels may be, we still need a bit of heft to support cleats. This pic shows the area we're talking about.

With handle removed, the RAS sander just fit in this tight spot and made quick work of grinding out the high spots.

2 backing plates fashioned from G10 make bomb-proof backing material. The side to be glued was scuffed up with grinder for adhesion.

We mixed up MAS epoxy with 407 microballoons and cab-o-sil to peanut butter consistency. Again the 407 micro-balloon filler really helps this stuff stay put, crucial for overhead applications like this.

Buttered up the bonding side like it's a tile.

Then stuck it like a postage stamp, with some back and forth wiggle to bed it in place.

The excess is a good sign we've got enough glue in there to hold.

We did the exact same procedure on the port quarter.

These quarters are ready for some cleats.

Spotty Gunwales

The remaining epoxy made good filler for fairing patches we've made along the gunnels.

Dings and Dents

2010-06-04T08:37:00.000-07:00

Installment 38 of 19ft Mako Restoration

We're primed to restore the inboard sides where the fishboxes used to live. Before we close those sides up though, we mused over aft cleats. Always dangerous to start thinking midway through. "Hmmm...how's that gonna work when we can't reach em? Not very well now is it." Altered plan, let's prep for cleat install before we close up those sides.

In the meantime, we took a walk around the boat. There's a mess of minor crash damage dirtily repaired with 5200. Looks like heck. Time to pull out the grinder and make some patches.

We experimented with MAS resin thickened with cab-o-sil. Some light 6 oz cloth for strength over the small spots.

Scraps of Quadraxial cloth cut to size made excellent patches over larger damage.

Where damage was extensive, we tabbed the topside liner to the hull.

Once this stuff is cured, we'll skim over these areas with filler to even the surface.

Transom tie-in

Our gunnel to transom repair required a little more tweaking. We ground a smooth transition from new to old, and layered some 6 oz cloth to fair the dip with a bit of strength.

While we were at it, we prepped the sides for bonding. The RAS Rotary sander with 24 grit quickly extended the bevel a good 5 inches. These sides are shaping up!

Gunnel Growth

2010-05-28T12:59:00.000-07:00

Installment 37 of Mako 19 Restoration

We layered on another Quadraxial cloth over the gunwale/transom cutout. This cloth is great for quick buildup.

The previous application just covered the gap with an inch or two contact along the perimeter. This next cut extends much further forward 6 inches or more.

We wrapped it slightly over the transom.

Finished off with a little stay put mojo.

For the starboard quarter we covered this whole mess over.

2 layers of quadraxial roughly equates to 3 layers of 1708 biaxial cloth. No deflection on these corners at-all. A little touch-up work and we're now ready to build down the sides.

Piercing the nose

2010-05-28T06:16:00.000-07:00

Installment 36 of Mako CC Restoration Blog

Previously, we fashioned and bonded in a new penske bow eye backing stem. It's cured rock hard and ready for some hardware. Our job this night among others, was putting a ring on the nose of this boat.

For jewelry, we grabbed a hefty oversized stainless 1/2" boweye. This beefed up version has much wider hole spacing. So to start, we drilled a pilot hole for spacing, then drilled again to size, through hull and penske backer. Penske is super high-density glass impregnated foam. We weren't sure if the penske would compress over time, loosening the backing nuts. To rule out this fear, we cut a rectangular G-10 backing plate for insurance. This is a critical anchor point when trailering, mooring, or heaven forbid receiving an assistance tow. For that reason, we shamelessly way overbuilt it for the long haul. Once Humpty boat is back together again, access to this spot is granted only with persuasion from a saw.

We dry fit everything first and ground down all high spots as needed.

A concoction of West epoxy and 407 thickener mixed to peanut butter consistency made great bedding.

Only trick - sticking it backwards over head without a disaster.

Phew!

With artist cap on, TJ prettied it up from the outside, prep work for when we eventually repaint this beast.

Presto! That should hold the Queen Mary.

Bridge the Gap

2010-05-20T13:29:00.000-07:00

Installment 35 of Classic Mako Blog

We have a hole to fill. Well, ok, actually a bunch, but let's talk gunwales here. This pic shows the cut made to re-core transom. Three layers of cloth now cover that exposed core, but the gap on the rail is still there. Time to fix that.

We ground a wide bevel around the bonding area.

Might as well grind out this crushed fiberglass on the corner edge and glass that too.

We came up with this high tech mold for extending the splash rail shape ...

High tech cellophane wrap for mold release

Quadraxial cloth wet out with epoxy makes for quick bulk build-up.

All cured, we're satisfied with the rough shape of this first layer. Several more layers, each successively wider, will finish this repair.

Prepping for the Nose Ring

2010-05-20T12:55:00.000-07:00

Installment 34 of Mako Reconstruction Project

We drew straws to crawl up under the bow and yank out the old boweye and backing block. I lost. How is it each and every boat has one incredibly uncomfortable spot like no other, and at some point you have to stuff yourself in it. This wood backing was in surprisingly good shape for 30 plus years abuse.

But continuing our modernizing theme, we're going to replace this wood with some rot resistance material.

We grabbed some scrap penske board left over from the transom job. Since the 3/4" thickness wouldn't cut it, TJ grabbed some 5 minute epoxy and bonded two strips together.

We then cut it to shape with a carpenters pull saw.

I buttered the area first with epoxy thickened with cabosil and 407 filler, then smeared more on the stem and set it home. I like the stick properties of 407 additive for holding stuff like this in place.

With a gloved hand I smooshed all the oozed epoxy into any voids around the perimeter and smoothed the backing surface. We'll add a load bearing backup such as G-10 to the face of this when the bow-eye is installed later.

Dressing up the Bilge

2010-05-20T09:18:00.001-07:00

Installment 33 of Mako Project

Before we close up this bilge, a fresh coat of paint will pretty her up and add protection.

We grabbed some Interlux Bilgekote and painted the center span the length of the boat.

You may notice the setting of boat has changed also. With warm summer near, we've moved the old Mako into the unheated warehouse building where we can kick up dust with reckless abandon. Having the boat on two of these PWC dolly's is slick. Any time we need to slide her over, we just pull the boat stands and give a shove. The casters allow you to spin her in place or roll her across a parking lot. Much easier than pulling a trailer.

Bilgekote is easy, one part application you can spray, brush, roll or roller-tip. Since this is going over freshly laid fiberglass, we prepped with a quick sand to shake off the amine blush followed by a shopvac.

We rolled with a semi-smooth 3/8" nap roller and 3" chip brush. Directions say to roller tip bilgekote, but since our unfaired glass has a rough texture anyway, we just rolled it on assuring good coverage. She'll look pretty clean to anyone poking their head down the access hatch. Next we'll replace the stem and bow-eye while accessible.

Tying in Loose Ends

2010-05-20T08:59:00.000-07:00

Installment 32 of Mako 19 restoration

Mako feels solid. She's got new stringers, new transom and several layers of new glass in the hull. Before we re-deck this old bird, we want to make sure everything below is shipshape.

Reinforce the chine

To transition that added stiffness from hull bottom to the sides, we reinforced the chine with fiberglass tape over the exposed sides.

We laid in 7-1/2" wide strips of quadraxial cloth the length of the hull from transom to bow.

This area will soon be inaccessible once the decks are re-installed.

This extra reinforcement spreads the stiffness to the sides and should quiet hull flex considerably.

Transom Wrap-up

We glassed one final skin inside the transom to prevent engine bolt creep and maximize stiffness. To recap, our new transom has two layers of 1708 laid on the inner face of the outside skin, two panels of 3/4" Penske core, equaling 1-1/2" total core thickness, then two more layers of the same 1708 biaxial cloth. One more final layer completes the laminate. We laid 24 oz cloth with Trevira backing cut for a generous wrap along sides and bottom.

The cut drapes over the top edge, and the bottom has a generous 8 plus inches overlay on the hull and stringers. This encapsulates those tie-in strips from the stringer installation.

We also wrapped the cut another foot along the sides for added beef.

All cured, it's a huge difference. Any hull deflection around the corners is nearly gone. Extra material on the corners compensates for the missing fish box corner structure left out. It also prevents the symptomatic stress cracks in the transom corners seen in most old boats.

The structural phase of the hull is complete. We're going to move our attention upwards to the gunwales and deck, once we've completed one last dressin-up. The sanding dust in these pictures is prep-work for our next phase- painting the bilge.

Limbering Up

2010-05-20T07:46:00.000-07:00

Installment 31 of Mako Rebuild

Our foam core stringers are in and look great. We'll add some finishing touches to complete the job. For water to drain into the bilge and out the garboard drain, we cut limber holes. The steps are very easy. TJ grabbed the cordless drill with a 2 inch hole saw. We cut 2 inch PVC pipe the width of each stringer and dry fit them in place.

Once we were happy with the fit, we thickened some epoxy with 407 low density filler and coloidal silica to a thick peanut butter consistency and spread it with a gloved hand over the inside of the hole to seal it. We also added some to the cut PVC and inserted into the stringer.

This gets messy, so have some rags on hand.

We let this cure then returned with a Rotex sander and sanded the tube flush for aesthetics.

With some more of the same epoxy mix, we dressed out the remainder of the area to a smooth finish, trying to keep a smooth transition through the limber hole. This will pass debris up to 2 inch diameter, so it is less likely clog. The PVC lends some structural strength while protecting the integrity of our stringers down the road. Overall, it's a huge improvement over this failed stuff...
While TJ worked on the limber holes, I did some spot repair on stringer butt joints. There were a few unavoidable buckles in our laminate installation caused by the curve of the hull. I ground out the large voids with the RAS sander and 36 grit disc. Once the voids were cleared, I cut some tabs of Quadraxial cloth. Where needed, I filled in with some thickened then laid the wet out tabs over top.

All said it looks pretty darn good. We'll add one last finishing touch on the next post, reinforcing stringer to transom

Tying into transom

2010-03-22T17:00:00.000-07:00

Installment 30 of Mako Project

With all the stringers laid in the hull, we had one last order of business to tidy up this installation. From outside the hull, Mike added some tie-in strips of quadraxial cloth.

To tie the stringers into the transom, Mike cut some 14 inch long quadraxial strips to size and attached them to top and 8 inch strips to sides of each stringer and stiffener. We wet out with epoxy and brush and rolled it out with laminating roller. A fourth strip saddled the tabs in place over the stringer.

Because these stringers are already quite high, adding knees to the transom is unnecessary (nor is there much room for them). We'll lock these tabs in place with one more layer of 24 oz 0°-90° inside the transom. This final layer will build up sufficient transom thickness for to carry the heavy outboard.

We had some time to spare with Scott and Mike before their ticket back to the Florida sun. In all, the stringer and stiffener installation took less than one business day to complete using the Preform system, not too shabby. We are extremely grateful for all their help and insight, and very impressed with the results.

The next day, with the epoxy cured dry to the touch, we rolled this old boat out into the light of day, the first time she'd seen the sun since the stringers were removed. She holds her shape with no sagging. Walking around inside the boat or rolling her over bumpy pavement, she feels rock solid, no more walking on eggshells.

Drive-thru Stringer Installation

2010-03-22T08:15:00.000-07:00

Installment 29 of Mako Restoration

Day two of the Prisma visit, and we're ready to finish up - this post we're installing the stringers. The previous day we completed the stiffener installation, and it cured hard by the time we returned the next morning.
Those stiffeners installed fairly easy since it lay higher in the hull on the flats. Installing the stringers is more challenging; the stringers are closer to the keel, and span complex angles and turns up forward. Getting a flush fit can be a head scratcher. But we have a plan of attack.

Having Scott and Mike from Prisma onboard for this stage was an incredible boost. Their experience and expertise guided us easily through the process without sweating insignificant details. Together we dry fit the stringers to the hull.

The upsweep in the bow was problematic; it caused the stringers to bridge. For a perfect fit we'd need to shave the underside through trial and error, or trowel out some thickened bedding compound. Either option would eat up valuable time. But Scott reminded us the load is actually carried through the fiberglass not the foam. The foam core simply secures the fiberlass laminate shape from deflection, thus giving it exponentially more strength. A simple relief wedge cut out of each stringer gave a sufficient fit. It worked for this boat because the deck floats above the stringers not on them. The relief cut hinged the stringer with the bend to achieve adequate hull contact (though not perfectly flush.) We laid it out and everything looked shipshape. Mike hopped in the boat and TJ and I suited up to work the laminating table.

We're again using epoxy to glass in the stringers since the earlier stages were completed with epoxy also. (Polyester resin is the common go-to for this, but should only be used when bonding to a polyester based hull.) With temps in the 60° range, we're going with 105/206 slow mix to get the desirable work time.
We passed the first sections into Mike and he set them in the hull. Notice the index marks on the transom for alignment. Mike kept a tape measure onhand to assure alignment.

This job is best done with several sets of hands. We wet out on the table, making sure the spun polyester backing (aka Trevira™ or Duraspun™) is completely saturated and the quadraxial cloth has a translucent soak of epoxy.
We fed Mike a steady supply of epoxy so he could complete the wet out. He kept a laminating roller and chip brush on-hand, along with a healthy layer of gloves to peel away as needed.

Where the stringers butt together, Mike covered the joint with 6" wide strips of quadraxial cloth.

Wood strapping and some old fashioned gravity helped tack these stringers in place while curing. Be sure to add a poly sheeting barrier to keep the wood from bonding to the stingers. We sat heavy 5 gallon pails atop the wood for pressure.

Where the deadrise (V) is steep, Mike drilled some drywall screws through the spacing planks into the stringer to keep them from sliding down.

With all the stringers set in and wet out, Mike stepped out of the Mako and hung the "do not disturb" as we stepped away. A few tie in strips to the transom will finish the job up. (included in next post)

Skeleton Crew

2010-03-22T07:27:00.000-07:00

Installment 28 of Project Mako Relaunch

We're ready- time to regenerate bone structure in this old Mako. Last week we kicked the project in overdrive ; we needed to laminate enough hull strength in time for a very important visit. This next phase brings in a couple of expert stringer installers. Scott Lewit and Mike Canfield will be joining us from Prisma Composite Preforms in Melbourne, FL. They're here to guide us through installing stringers.

Scott and Mike are specialists in installing foam core stringers. Prisma supplies foam core composite hull reinforcements to many of the major OM boatbuilders. This modular boatbuilding concept is drawing the attention of many recreational boat restorers like ourselves. They offer a whole line of foam core composite reinforcements to structure any composite boat. The guys arrived at the JD workshop Tuesday afternoon. By mid-day Wednesday, using their prefab components, we completely installed new stringers and stiffeners in a few hour's work. It was easy. We're sold on it's value- huge savings on time and labor.

First step is to dry fit the stringer sections to the hull. The preform hull lumber ships in 4 ft lengths, so we butted several to gauge the run. We looked foremost at the deadrise angle. The stringers come in 3 deadrise options, 15°, 18° and 26°. Ideally stringers should be perfectly perpendicular. This presents a squared horizontal top to rest the deck on. The Mako 19 is different. Instead of landing the deck on stringers, she was built with a suspended deck. A suspended deck floats above the stringers through it's own support structure. Since the deck doesn't land on the stringer, a few degrees of deadrise slop is no problem in our new stringers.

Most boats will require some deadrise angle fine tuning. Mike showed us how to square up the stringers to vertical. Option one, Prisma offers deadrise converters, angled shims the stringer sits on top of to make it plumb. The other option is to shave away foam til the stringer sits perfectly up and down. To measure the cut, simply tip the stringer until the top measures level (using a combination level) and measure the gap. Mark this height on opposite side and shave that material off. Now that you have a mark, the easy way cut this:

scribe the gap height on the longer side of stringer, the side in contact with hull

draw this height the length of the stringer

then score the fabric with a razor knife, peel away cloth tabbing

next, looking at the cross section, draw a line from mark to opposite bottom corner

cut the foam with a hand saw.

You are left with a perfectly level stringer. Shaving foam will shorten stringer height, reducing structural support, so be sure you have height to spare. If not, the angle converters are a better option.

If there is a sharp deadrise, keeping the stringers in place can pose a challenge. We cut some boards as spacers in advance. These will maintain the stringer spacing and we will suspend weight on them til cured.

Cutting the stringer to transom angle

measure the stringer distance. We left the full length 4' sections intact up forward and opted to shorten the aft stringer.

After marking the distance, cut the cloth face with a utility knife

Also cut the tabbing quadraxial cloth with scissors

Use a hand saw to cut foam

Place stringer against transom and measure the gap. Most transom angles will see the gap up top. Mark that measured distance on the BASE of the stringer to make the angle agree.

Connect the dots from top corner to the measured distance

Again, cut first with the razor knife and peel away all attached fabric.

Finish the cut with a hand saw

The resulting angle should fit flush to the transom.

All prep work complete, it was now time to wetout. We installed hull stiffeners first, and returned to the stringers next day. Prisma offers a great carbon topped hull stiffener that adds significant hull strength while adding very little weight.

We prepped the area with a light 36 grit sanding to add tooth and shake off any amine blush.

On the laminating table, TJ and I wet out each 4' piece with West System 105 and 206 Slow hardener and passed them into the boat. Mike set the stiffeners in place and chased bubbles with a roller. He kept a small batch of epoxy on hand to saturate any remaining areas. Where the stiffener pieces butted together, we overlaid tabs of quadraxial cloth.

We finished the wetout in less than an hour. We'll cap the forward ends and tab the back into transom sometime later. For now, time to let the stiffeners cure and come back tomorrow for stringers.

More Bulk - 24 oz

2010-03-16T10:43:00.000-07:00

Installment 27 of Mako Restoration

The time is near! TJ and I are suited up for an all out blitz to whip this hull into shape. Help is packing their bags, they're touching down at TFGreen next day for our scheduled stringer installation. With hustle and some extra late nights we already completed laminating a layer of 36 oz quadraxial cloth. Tonight we're not leaving til a complete 24 oz lamination is in this hull! Stick around, it promises to be exciting...

We have a 35" wide roll of 24 oz /yd² cloth with a standard 0°-90° weave. This cloth also includes the same polyester Trevira™ backing as on the Quadraxial cloth. It will bring this boat up to and beyond it's original hull stiffness. We overlapped strips across the boat to counter the fore & aft overlap of the Quadrax layer. Same coverage area as the quadraxial layer, looking for 3-5" of overlap, and butting it right up to the chine on the sides. We again used West System 105 with 206 slow hardener.

Dry cut all cloth in advance to assure fit.

We split the foremost bow strip in two, allowing overlap each side of the keel.

One last thought before jumping in. Make sure that flimsy hull is in alignment. Any warp and twist will cure permanently to shape, making one odd boat. Everything looked plumb, it was time to roll.

Tackle the diciest section first- we began in the bow. The wider cloth made this stage messy. A bit of strategy is required, since you must lie in the steep hull you are wetting out. Sitting in the bow, I aligned the dry cloth. I folded one panel in half, wet out the back and stuck it forward then chased out the bubbles. Hinge it the other way, resin the back, and flip the aft half in place. Not too difficult. Now the same steps on the port side while I sit on cloth that is mostly dry. I returned to wet out on top last; here it gets tricky.

TJ passed in a fresh mix of epoxy. I poured the resin over-top the cloth to starboard and spread it with squeegee or chip brush, and chased out any bubbles. Switched to the port side and now there's nowhere dry left to sit. I pulled the dry cloth from the next aft section and set it underneath me. Laying on this dry "mat," I wet out the port side and chased out bubbles. Gloved hands made the best bubble chasers in tight spots. There's no helping this one, it's a messy job. Just tried to keep it off any skin. Epoxy is itchy stuff.

Funny angles and limited workspace took time to laminate. So meanwhile, TJ brought the epoxy aft and began wetting out the stern. Now we both had room to operate and planned to meet in the middle.

We opted to spread the resin in the hull as opposed to on a table. The Trevira™ backing received a thorough wet out first and then we set it in place. Mixing, pouring, spreading. Good tunes. We found our groove. A few hours flew by. TJ progressed steadily forward from the transom while I worked back from the bow. Once you start this job, gloves covered in resin, there's no stopping til it's done. Murphy's Law, itchy nose, Itchy Nose, ITCHY NOSE, someone please scratch my nose!

Down to the last and final strip. This was the biggest challenge, no where dry to hide. We strategically saved the strip just behind the foredeck step for last. That nice cross beam was support to lay and brace on. Some slipping and sliding but we made it happen. Laminating rollers on extension handles worked great for final touches from a step ladder.

Surprised by the late hour, it was time to close up shop, boost the room temp and head home. This was one of our longest nights. We headed home happy, deadline met and promises kept. Next step stringers! This boat is coming together.

Port Quad Run

2010-03-16T09:07:00.000-07:00

We're feeling the crunch to complete this phase. Scott Lewit of Prisma Preforms will be flying in from Florida in a couple days. He's offered to walk us through the stringer installation using Preform stringers. We need everything in order beforehand. That means completing the base layup in a few short evenings. After tonight's quadraxial cloth, we're shooting to add a layer of 24 oz 0°-90°. And all this needs to be done in 2 nights. It's gonna be close.

A late Sunday night session jolted this phase one step closer to completion. With starboard side already reinforced, Sunday's game plan is to do the same to port side. I cut several strips from the 15" wide quadrax roll as before, using a paper template for the most outboard strip. Shaping cloth is easy with these electric shears. I love these things!

The Quadrax cloth has a spun polyester Trevira™ backing. This backing makes laminating the cloth very different, it soaks up resin and we wanted to be extra sure the underside was wet out thoroughly. This Sunday night I was flying solo, so work time was critical. To keep things easy, I wet the strip out in the hull, the backing first, then flipped it up and over into place. It worked like a charm. The cloth wet out much quicker this way.

As before, opened garage doors helped lower room temp for extended pot life. Once the laminating process was complete I closed up shop to boost the temps. Highest strip first, I laminated progressively down towards the center. This way any epoxy runoff worked favorably and there was dry area to work from. I pulled the next dry cloth under me to keep out of the resin. This heavy cloth doesn't distort easily, otherwise you wouldn't want to abuse the weave this way.

This is a great shot of the bow section. We will be replacing the stem later, so we've left that area accessible. The cloth lays nice and flush with no lifting.

We butted the strips flush to the chine where it curves around the bow.

Each layer overlaps 3-5" for strength.

The fillet we laid in the chine eased the abrupt turn. The cloth laid down very nicely there with no tenting.

The resin was beginning to gel as I chased out the last remaining air with a bubble buster roller. That's the curtain call for this stage. With lower back burning it was time to step out of this boat and let it all cure.

We'll be ready for the 24 oz cloth tomorrow night. Then the following day it's time for stringers!

Laying Down the Heavy

2010-03-11T09:35:00.000-08:00

By our next shop session the center strip of Quadrax cured rock hard. Just stepping in the hull was noticeably stiffer. This is the way to go- quick and easy strength. Time to add some more. We're going to split this stage in two, glass the starboard side first, let it cure, then glass the port side after. Otherwise we'll be lying in wet resin, a very stick proposition! In total we estimate covering 80" x 180" of hull area .

The Quadrax is on a 15" wide roll, so we dry fit three strips in advance. For the outside run we used a roll of masking paper to make the template, simply following the chine with a sharpie.

Once the quadrax was cut, we sized it and it looks spot on.

We cut it so the fabric just curled into the chine but not up the sides. We'll come back after with some 6" wide tape to finish tying in that angle.

The cloth runs all the way aft to about 2 inches up the transom.

With everything in order, we began the mixing. Again, we went to West 105 and 206 slow.

Starting with the highest strip, we spread neat epoxy on the hull with chip brushes and roller then aligned the fabric over. We poured the resin and squeeged it out with spreader.

As the fabric wet out we worked all the air out with laminating rollers. 15" wide strips make bubble chasing manageable. We walked our way towards the keel with each layer. Keeping the cloth flush on the sharply angled bow was tricky. The best solution we found was to fold the cloth back on itself, back wet it and stick it like a postage stamp to the steep bow. We finished the wetout spreading more resin with a chip brush on top and worked out any air with gloved hands. All strips had at least a 3 inch overlap.

We're half way there.

The Buildup

2010-03-09T10:49:00.001-08:00

Supplies! Supplies!
Winds of good fortune blew in this week bearing a shipment from Florida. TJ and I sifted through the boxes marked with the Prisma emblem like kids in a candy store. These boxes contain the new skin and bones for the Mako-
"Check out these stringers," (eight 4' sections.)
"Here's hull the smaller hull stiffeners with the carbon cloth top," (four 4' sections.)
"Two beefy looking 3" panels, possibly for knees." And a boatload of cloth. This will be be a stout little boat.

The Fiberglass included a roll of Quadraxial. The specs on the cloth:

36 oz per square yard
4 layers of alternating weave (0°/90°/±45°)
non-woven polyester Trevira™ backing

We're excited about the strength of this quadrax though we've yet to work with it. It's thick! 36 ounces per yard means fast strength build with a fraction of the labor. Quad means there are 4 layers of fibers, each oriented in opposing directions. It adds stability in all directions, (0°, 90°, +45°, -45°) and the polyester Trevira (aka T-mat) backing conforms to the hull shape and prevents peeling away. Once T-mat is bonded to a hull, there is no risk of delam. Only a grinder will take this stuff off.

We started with the complex curves of the keel. We rolled it out and cut it to length.

We cut a second strip to size it up. We're looking for a 3-5" overlap on the sides of each strip.

This center strip spans from just under the stem up forward back to the transom.

We tackled the most complex run first, the keel. The gradual inward and upward sweep of the bow (deadrise and shear), forced the cloth to buckle. To tame it, we split the strip where the curve steepens, about 5 feet or so to the end. We criss-crossed theses strips so each lay flush.

The surface has already been sanded, so no prep is needed. We're ready to wet out. Next choice, Polyester or Epoxy resins. Either will work, but several reasons shouted epoxy. First thought is the bond; we used epoxy on the transom and chine fillets. Polyester makes a strong mechanical bond to itself, but doesn't play well with epoxy. Epoxy on the other hand bonds to most surfaces. Secondly, the smell indoors. Our workshop here at Jamestown Distributors abuts retail, warehouse and office space. Polyester gives off an overpowering styrene smell. We're indoors and our coworkers would not be happy. Epoxy smell is mild in comparison. Lastly, performance; epoxy results in better strength and stiffness per weight. If you're choosing, either works; more economical polyester will bond to old polyester hulls- so long as no Poly over Epoxy, it's fine the other way around.

The resin of choice? Epoxy dujour- West System 105 since we have an abundance of it on hand. A dedicated laminating resin like MAS low viscosity or System Three clear coat is nice, it wets out easier and quicker, especially on thick cloth applications. We tried standard 105 resin and had no trouble in the 50-60° workshop. If you're working in hot temps or in large scale the quick wetout is great, but moderate temps gave us a long window and no problems.

Lots of mixing! Polyester can be mixed in bigger batches, but because epoxy is exothermic, the batches have to be kept small. Big epoxy batches cook quick. TJ volunteered as designated mixer and I climbed in, Tyveked to the max. A helpful tip for large layups is taping off the sleeve cuffs or better yet, double up with some tyvek sleeves over the coveralls. Otherwise your wrists pop out with every reach. Also layer on the gloves. You can peel them off as needed.

We used West System 105 with 206 slow hardener to extend our working time. We grabbed a foam roller and roller tray, and rolled out unthickened epoxy underneath.

We dropped the cloth over and wet out til no dry spots remained. The longest part of the whole process? Bubble busting the entire run, a span from the stem on the bow to a few inches up the transom. We chased any bubbles out the sides with laminating rollers and squeegees.

The Rising Tide

2010-03-09T10:00:00.000-08:00

Demolition phase 2 is complete. The Mako interior lays bare and scoured clean like fresh sand exposed at low tide. She's ready, bow out, eagerly awaiting the gurgling lift of incoming tide. This build is rushing in on the visible horizon. Next step, shore up the hull with a new schedule of fiberglass.

In stripping away the detritus, we've weakened this hull considerably. Our first order of business, stiffen her back. We want a rock solid base layer, so we consulted Prisma Composite Preforms, experts in composite construction. They've advised a new layup which will form the foundation for their preform stringers and stiffeners. Modern designs achieve a lightweight, stiff hull via a cored laminate construction. But this vintage Mako was straight fiberglass without core. Prisma engineers devised an improved schedule of fiberglass that is stiffer than original. The first application will be Quadraxial cloth, followed by 24 oz 0°x90° cloth which Prisma distributes. The Quadraxial cloth is 4 layers in one cloth, each weave alternates a different direction (0°, +45°, -45°, 90°). We'll elaborate more on this in the next post.

We had yet to get our hands on the quadrax but expected a heavy cloth where it's drapability is stiff like biax. Heavy cloth poses a challenge for hand layup - air pockets. Small voids were throughout the original build. Grinding off the old roving revealed loads of air pockets, particularly at the hard turn on the chines. In a morning coffee gam session TJ and I leaned over the transom and threw out some problem solving ideas- what if we smooth the sharp transitions with a fillet. The fillet will ease the bend in the cloth maximizing the bond.

We mixed West 105 /205 with a hefty dose of milled glass filler and filled the V in the bow. This mixture needed something more to prevent sagging, so we added enough 407 low density filler to make it stay put on the sloped sides. We also spot patched some voids in the stern with the remainder of the batch.

The gray in the bow is the milled glass mix, the shiny brown is the same mix with 407 added. Once cured we passed the sander over it with some 120 grit and faired this to a fillet-like easy curve.

This hull is clean and ready for the big show. Time to dress her up with some Quadrax!

Through the Dead of Winter

2010-02-25T13:54:00.000-08:00

Man, what a trip! With many tedious nights of hand numbing work behind us, our most recent phase of project Mako is complete. We feel excitement growing with the increasing daylight and sprouts peaking up from the ground. We've turned a major corner in our workshop, shaking off the dead of winter. We're ready to add new growth to this boat.
Our goals for this stage:

Remove the old stringers

Peel and grind away all weak laminate

Scour off any trace of foam and contaminants

First, removing the old stringers:
We sampled several different tools to get the job done, beginning with the cut off wheel. This tool works great for hogging through fiberglass. But the deadrise made sharp angles which the tool couldn't quite access. Not the best option for this job.

We opted for the teeth chattering muscle of the sabre saw next to zip the stringers off. It cut quickly, but the long range of motion risked punching through the hull with one slip, especially on the upward angle of the deadrise. We removed a few stringers with this reciprocating saw, but it left behind high nubs with the remaining core still firmly bedded in place. It still required alot of cleanup work.

The best tool for this job - the multimaster. We hooked on the high speed steel saw blade. While it cut through laminate and plywood slower, the controlled flush cut actually saved more time overall. In fact, once the fiberglass encapsulating the plywood core was cut, we were able to rock and knock the stringer out. We still needed to cut and grind all traces of the stringer away, but there was much less cleanup using the multimaster.

The stringers were surprisingly still semi-solid overall, though soaking wet through and through. That's some good wood to stand up 30+ years. We've removed a good deal of dead weight here. The cracked sections of fiberglass were the worst, the core a splintered mush as expected.

Our next step was to get down to the good stuff. Bonding new fiberglass to a delaminated layer would only peel away under stress. We needed to remove and grind away any suspect areas. Poorly bonded top layers have an opaqueness where the bond separates. This can happen to bare fiberglass over time from constant water exposure, in this case from the saturated foam. Much of the top layer of woven roving needed removal to expose good bonding surface.

We set in, grinding and cutting away the nubby remains of the stringers. We could have saved this step, because an exploratory peel of some delaminated woven roving became a wholesale removal of the top layer. TJ wedged the pry-bar under the top layer of woven roving in exposed stringer bed. It peeled off like dead skin. Peeling it away revealed the exact composition of the layup, or "schedule." Below the woven roving was a chopped strand mat layer. Below that was the first base layer of fiberglass in the mold. The peel brought most of the chopped strand mat with it. What remains is now a good pinkish hue of solid fiberglass, an excellent bonding surface for our next step.

These samples of Prisma stringers hint towards what comes next.

Before

After

Before

After

The hull now flexes under foot enough to make us squeamish. We have to mind our step. We will address this next before adding in new stringers.

Many grueling hours later we feel good about the results. We're excited to begin building up the inside of this hull.

Better Limber Holes

2009-12-09T14:34:00.000-08:00

This article from Professional BoatBuilder has excellent ideas on designing bulletproof stringers and bulkheads that will last. It talks about the issue of limber holes, those passages through bulkheads and structural components to drain water to the lowest part of the bilge. "The Humble Limber Hole" by Bruce Pfund TJ and I plan to take a few pages from Bruce's book on the new stringers we'll be installing. Check it out.

Stringer Appeal

2009-12-04T14:26:00.001-08:00

Installment XX in the chronicles of a Mako classic restoration

We are now ready to make some progress with stringers (longitudinal reinforcing beams on the hull.) The original stringers were marine plywood covered in a heavy fiberglass woven roving cloth and wet out with polyester resin. Holes called "limber holes" were cut to allow water to drain to the bilge. These vintage limber holes are a horror show. A hole saw cut through the beam left exposed wood core. Water migrated in and rotted these areas. The rotten core shows black through the fiberglass. Notice the cracked areas.

These beams bear the brunt of force when pounding through waves. Hard spots and rotted core spell failure.

To remedy this, our task is to grind these stringers off and replace with new. Rotten core has minimal strength and must be extracted. Spot repair and/or sistering in stringers supports is the easiest route with least time and expense. We're going for the gold- grind the old stringers flush, then replace with foam core stringers. We chose these pre-fabricated stringers by Prisma. Prisma Composite Preforms come in complete sections, ready to wet out. The fiberglass fabric is already bonded to the foam. Just bed in place then wet out.

To spec out the stringers, we carefully measured and snapped extensive pictures of the current hull stringers. Measurements should include:

angle of deadrise (angle of the hull to perpendicular)
length of each stringer
depth of each stringer

We then emailed this info on to the folks at Prisma for technical consultation.

Without stringers, this boat will be loosey goosey. One concern with the upcoming phase will be to maintain hull shape. We must support the hull prior to removing the stringers to minimize distortion. Temporary braces across the gunwales and supports under the hull should maintain hull shape as best possible.

Commonly decks rest directly on hull stringers. Notice this boat has separate reinforcements for the deck, which floats above the stringers. (see 2 remaining nubs in middle) We have the option to replicate this or just mount directly on stringers.

This perspective shows the taper of stringers meeting the rise in the bow.

Thanks for joining us, and please check back for more.

Transom Wrap-up

2009-12-03T08:11:00.000-08:00

Installment XIX in the chronicles of a Mako classic restoration

We measured out 5 parts 105 resin to 1 part 205 hardener by volume. When metering large amounts, it's much easier to pour than pump. This is where graduated mixing pots come in handy.

We wet out the first two biaxial strips on the table and transferred them to the boat.

We then proceeded wetting out the 6 ounce cloth, laid it in place and bubble busted once again with the laminating rollers.

Gloves are getting pretty tacky at this point. Layering gloves is the way to go- just peel off a layer and keep on rolling.

We made incisions in the dry cloth at each of the sharp bends of the transom notch. The cuts are needed for the tape to lay flat. To make sure they aligned we marked the port/starboard sides with a permanent marker.

Murphy's Law- the worst possible time for an irresistible itch on your nose

Bubble busting with laminating rollers.

Holy cow- is that the time? Let's call it a night. Before heading out, dunk those laminating rollers in an acetone bath if you wish to use them again. Otherwise they become more spreader than roller ;P

Over the Top

2009-11-26T10:00:00.000-08:00

Installment XVIII chronicling of the restoration of a classic Mako runabout

With prep work completed last week, we're ready to cap the top edge of the transom with fiberglass. We planned out a schedule of various cloth to encapsulate the transom top. To cover the top edge precisely, we cut 4" biaxial tape in 2" strips to lay down first. We then cut two progressively wider strips of 6 ounce boat cloth.

Sizing up some lighter cloth that will drape the hard corners.

2 layers of Biax tape first covered with 2 increasingly larger widths of 6 ounce boat cloth

Love these little electric shears.
They cut through any cloth
without making a frayed mess
or destroying the weave.

2 layers of biaxial tape and 2 wider layers of 6 oz cloth laid out in order on the table

Let's get ready to roll. Gloves are a must for this part.

All joking aside, pumps become tedious when measuring large volumes.
Pull em out and pour by volume.

"Hey, quit pointing that thing at me."

All 4 layers of cloth are laid out in order. Spreaders, a couple of laminating rollers, mixing pots, resin/hardener, mixing sticks, extra gloves - check. Looks like we're ready- let's wet this stuff out!

Taking the Edge Off

2009-11-19T09:40:00.000-08:00

Installment XVII in the rebuild of a Mako center console

By next Wednesday's session the transom cured rock solid. Our goal tonight was to clean up her top edge so we can layer some fiberglass tape over it. The stiff biaxial cloth did not stay tacked on over the outside of the transom. The cured edges needed grinding back to where there was a solid bond (core to laminate). Great job for this Dyanbrade cut-off wheel.

Almost done grinding stray edges off.

Once all the stray glass was nibbed off, we followed up with the Rotex sander and ETS 125 sander to grind away any remaining un-bonded glass. We also gave all the freshly cured glass a quick wetsand to de-burr it and remove any traces of amine blush. The surface is now ready for TJ and I to cap it with several layers of fiberglass tape. But we'll tackle that next week.

A Midsummer Interlude

2009-11-12T11:17:00.000-08:00

For our devoted following, we could list a thousand excuses for the long hiatus since our last spring post.
But a picture is worth a 1000 words and excuses are for, ummmm, well, these two guys. Our apologies.

Here's what TJ and I were up to that kept Mako progress at bay...

Now back to our regular scheduled program...

Inside Skin

2009-11-09T09:36:00.000-08:00

Installment XVI in the chronicles of a Mako classic restoration

Prior to our summer break from project Mako, we completed bedding in two 3/4" sheets of Penske core in the transom. It's been strategically pickling ever since ;) Our goal now is to encapsulate the transom and move on to the stringer replacement. We're a long ways from the finish line, so it's time to get rolling. We're shooting for this Mako floating pretty next summer.

A quick chalk talk and we've got our game plan. Next step - lay cloth inboard of the transom. We again chose 1708 biaxial cloth for inside the boat, two layers to be exact. We wet out with 105/205 West System. 1708 Biax builds bulk quick with lots of impact and load bearing strength. Sounds exactly right for a transom. Prior to layup, we meticulously prepped the surface with the following steps:

buttered a fillet joint edge into the bottom to make a gradual curve for best bond.
rounded all sharp edges from top and corners.
cleaned cured epoxy surfaces with soapy water and a scotchbrite pad to remove amine blush.
Wiped area clean: on w/ clean acetone soaked rag and immediately off with clean dry cotton cloth in other hand. This step can be omitted over foam core and wood substrates (see surface preparation article)
Abraded any smooth areas with coarse 80-120 grit sandpaper and dust off (not necessary over any porous substrates.)

We then placed the cloth inside the transom dry and traced the contour with a sharpie

The cloth cut was 5" beyond the transom contour to tab it over, around and under all connecting surfaces. Alternatively, you might cut the transom fabric exactly to size and then tab the perimeter with cloth tape.

With gloves and tyveks donned, I mixed up enough 105/205 at the 5:1 ratio to wet out the first layer. I spread a thin layer over the penske core with a chip brush to fill porosity and make sure there is no resin starved spots. Meanwhile TJ used the remainder of the batch to wet out the first 1708 over a laminating table. Once all the cloth was visibly wet out (translucent) we grabbed either end and transferred the slippery, sticky mess over to the transom. Easy now- one slip and this could get very dicey. The cloth should be laid with the chopped strand mat on the inside and biax weave on outside for best results.

This woven biaxial pattern faces out, ("laces out Dan!") random mat faces core.

The thinking is random oriented mat fibers hold more resin and make the best mate to rough surfaces. Thus, mat is the go-to first layer over core and 30 year old woven roving to prevent a resin-starved weak bond. Nobody wants that oh so evil word- DELAMINATION- oh the horror! 1708 integrates mat one side, cloth the other, making it an excellent base. With the sharpie outline showing proud, we stuffed the cloth like a bedsheet into place aligning the black outline to the contour. We then chased out bubbles with some laminating rollers to minimize air entrapment.

It's amazing how messy transferring wet cloth to the inside of a transom can be. Best advice, be prepared to throw away whatever layers you're wearing; but before you do, check out how your shirt stands on it's own the next morning- cool!

The 1708 does not drape well, as evidenced in the photo below.

No matter how well you tack it down, expect some cleanup with a grinder and cutoff wheel once this stuff kicks. Vacuum bagging is best option. The vacuum bag process sucks the cloth in place while it cures, negates air entrapment, and prevents cloth lifting away. With the complex turns in this form though, we opted out of vacuum bagging on this step.

As we left her to cure overnight we noticed it's awful quiet round here- music! - knew we forgot something. The radio's coming back next week. Once dry, we'll have a rock solid transom, cored with high density, high strength foam (penske) and reinforced with 2 layers of 1708 on both sides of the core.

Transom Bevel

2009-05-14T11:21:00.001-07:00

Installment XV in the chronicles of a Mako classic restoration
We returned the next morning eager to see how this old boat accepted her new core. The Penske core sandwich buttered with epoxy cured nicely, the clamps securely held everything in position. We removed the C-clamps and exterior 2x4 board handily. The bond between the new core and the old outside laminate skin was rock solid. Unavoidably, some epoxy ran through the bolt holes of our 2x4 clamping setup. Excess epoxy also drizzled down from the top. Thus our temporary clamp was also accidentally bonded rock solid to the inside in a few spots. It needed persuasion from the multimaster with an ecut blade to cut through the bond and free it up. We resisted the urge to tear the board free as the penske material is only a dense foam. The E-cut made a surgeon like incision which solved this problem perfectly.

This evening involved prep work in advance of the next stage, laying-up cloth inside the transom. We will lay 1708 biaxial cloth over top to the inside of the transom. To assure optimal bonding between old and new, a taper of 5:1 surface area to laminate thickness is recommended. We used a rotex orbital sander with coarse grit discs to grind the bonding area. [Beveled area pictured above, the tan area along the top of transom.] We rounded the top edges slightly and will add some thickened epoxy. Our goal is to fair any sharp edges to a smooth transition- this makes better bonding surface for the cloth.

Traces of epoxy oozed over night leaving a slight hollowing under the core bottom edge. Some epoxy thickened with high density 404 filler and cabosil remedied the voids under the core edge. With this same mix, we laid a fillet joint bead along the entire transom to hull edge. The back of a spoon or a gloved fingertip is all that's needed to create the concave fillet. The fillet shape forms a nice easy curve for cloth to adhere, which is our next step.

Gravity brought low some epoxy from up on high. Epoxy run is an inherent problem to both bonding and hand-layup of vertical surfaces. We filled the voids along the top corners with the same blend of epoxy thickened with high density filler. The remaining thickened epoxy we spread across the top transom edge to complete a nice smooth transition- like icing on a cake.

The complex form of the top corners will prove challenging to rebuild. We have ground out taper here and still have a bit more grinding to get the correct ratio for a proper bond. Our first layup in this area will focus purely on encapsulating the transom core. We will address the gap in the gunnel in a later step. Bridging that gap will require placing some temporary mold to lay wet-out cloth over.

The final consideration before the glass layup is assuring the surface is clean from contaminants. We will cover this in the next post.

Battening Down the Penske

2009-04-06T11:12:00.000-07:00

Installment XIV chronicling the rebuild of a center console Mako classicWith Tyvek suits donned we're ready to roll, like NASA storming down the street to capture ET (unfortunately, camera couldn't catch TJ's glowing finger trick) Thus far we've ripped out all the old rotten stuff, prepped the transom, filled the voids with thickened epoxy, added a layer of biaxial cloth, and now we're ready to replace the core. For core we've cut out two 3/4" Penske sheets, equalling 1-1/2" total core thickness.

We mixed up neat epoxy using the standard fast hardener and 105 resin. We spread this on both sides of the first Penske core sheet to fill in any porosity. We'll do the same to bonding side of the second Penske panel before installing it.

Just before setting the first core sheet in place, we mixed a batch of thickened epoxy. This we troweled approximately 1/8" thick on the boat where core edges meet hull, and thinner along the inside of the transom skin. The remaining thickened epoxy we distributed evenly over the joining faces of Penske core once the first panel was in place. The thickened mix assures a strong adhesive bond.

We needed a large clamp to secure everything. A couple of boards thru-bolted with long hex cap bolts and fender washers on either end did the trick. This kept the core in place under moderate pressure until it cured. (We cut the boards and pre-drilled them beforehand.) A liberal wax application to the bolts permitted removal post-cure. Though the inside board lay against dry core, a little epoxy slop inadvertently worked in there. Plastic sheeting would have prevented the board from bonding to the core wherever epoxy oozed. This occured to us in after thought and we later needed the multimaster to pop the inside board free. The bolts passed through the entire clamp setup. We drew tight the 4 hex nuts in sequence, a few turns of the ratchet per bolt to maintain even pressure. The pressure from our makeshift clamp squeezed out any excess epoxy.

Much of the thickened mixture displaced any remaining voids along the bottom base of the core, working to our advantage. We squeegeed away where necessary. Lastly, we braced the top edges with C-Clamps (with plastic sheeting in between). This entire setup was then left untouched to cure overnight.

To Biax or Not To Biax...

2009-03-27T11:09:00.000-07:00

Installment XIII in the reconstruction blog of a 1973 Mako center console

In this next step we will wet out and layup one layer of biaxial cloth inside the transom before bonding in new transom core. Our thinking - the 1708 biaxial will bolster strength and makeup for any minor deficiencies in the old transom skin.

We mixed up several batches of West System neat epoxy (no additives) and wet out the 1708 cloth on the table. There is a science to estimating the amount of epoxy needed to wet out cloth. We don't make any pretenses to be scientists; our formula= mix many small batches til we don't need anymore. We gently squeegeed it over the surface with a single edge spreader and let the cloth soak in the epoxy. Typically the cloth will become translucent as fibers soaks up and bond to the resin. This did not hold true for the biax, but more on that later.

Transfering the wet-out cloth to the transom is most certainly a messy two person procedure. An alternate method is to bring dry cloth over and wet it in place.

Once aligned, we chased out all air from under the cloth using laminating rollers and spreaders.

Notice the Biaxial cloth does not wet out completely clear. In hindsight we learned that styrenes in this "mat type" fiberglass cloth do not bond with epoxy as they do with polyester resin. (Biaxial is woven cloth one side and mat on other side.) Engineers at West System acknowledge this quirk between mat type fiberglass and epoxy in their literature. They also state it does not negatively impact the finished composite strength (from extensive testing). Yet any mat based fiberglass wetted out with epoxy will be less conformable (i.e. harder to drape over a shape) than the same mat cloth using polyester resin. Wow, who knew? Certainly not these two guys. Also, if this were a critical application where it needed to be clear, biax and epoxy should not be your mix of choice (i.e. a cold molded hull where beautiful mahogany shows clear through). Lucky for us, biax and epoxy are fine in this hidden and flat application. Henceforth though, I think we'll stick to regular 4 to 8 oz cloth compatible with epoxy.

With the biaxial cloth in place, we're now ready to bed in the core.

Mixing It Up

2009-03-26T11:05:00.000-07:00

Installment XII in this Classic Mako rebuild blog

In our post from the previous week, TJ and I completed prep work for replacing the transom core. Now it's time to put this core to bed. Our first order of business is to fill in all gaps so we don't leave any moisture trapping pockets behind.

We've moved the boat over to a nice clean and warm workshop for the epoxy application. 60 degree or better room temp is what we're after. For this whole process we've got a wealth of resin and hardener onhand. We also have a cache of mixing pots, mixing sticks, single edge spreaders, fillers, latex gloves and tyvek suits.
The transom area received one last go over with wire brush and vacuum. (See "Preparing Laminates" for more info.) Then we wiped it clean with acetone, let it flash off, and wiped dry with a clean dry cloth. We measured out the resin and hardener into separate graduated mixing pots, and then mixed them together. (Isolating resin and hardener during the measuring process allows us to recapture overpours. An alternative is pumping from the calibrated measuring pumps, but this proves tiresome and slow for large volumes.) We added a 50/50 mix of high density filler and coloidal silica until it was thickened to a peanut butter consistency.We layered on several pairs of gloves so we could peel off a layer without interupting workflow as the epoxy becomes tacky and tools stick. We then used spreaders to fill the epoxy mixture into all sharp angles and hollows, with a fillet joint bead lining the hull to transom joint. Our goal is to ease any sharp angles for the biax cloth, which we will layup in our next step.

This first step will fill voids so that in our final bonding step, when the core is clamped in under pressure, there are no voids. Clamping will squeeze out any excess epoxy which will then be removed. We mixed several small batches to complete this step. Large batches hold heat from the resin/hardener exotherm and will surely kick before you can apply it all. Should the epoxy "kick" in the pot, you'll feel the heat building in the mixing pot, and the epoxy balls up like chunky cookie dough as you spread it - not good. To forestall the heat buildup we could chill the resin beforehand or disperse the mixed epoxy in a flat pan, but it's easier- with less waste- just to mix in smaller portions.

We focused attention under the transom top edge and in the complex top corner where gunwale, transom and hull meet.

Once this step was completed we moved immediately to wetting out the biaxial cloth.

Core Strength

2009-03-12T11:01:00.000-07:00

Installment XI in the Mako rebuild project.
TJ and I have reached a major turning point - so far it's all been destruction to this old Mako. Now we're ready to build! After a fair amount of elbow grease cutting, grinding and chiseling out the old rotten core from the transom, we'll begin preparations to bond in new core.
Step one - we need a template for the new core. A large cardboard box worked well for this. Matching the exact core shape is a challenge since we destroyed the old core. We approximated the shape by first clamping the cardboard sheet lightly to the outside of the transom. We traced the exterior contours for a rough, oversized shape, too big to fit inside. Then we pared away excess to fit the inside the boat. An easier approach would be to drape a simple cloth over the inside and trace it with a sharpie, but we used what we had. Matching every intricate imperfection would be extremely tedious. We didn't sweat the details too much, any voids will be filled with thickened epoxy. We will ultimately bed our core into place with thickened epoxy, like a brick in mortar.

With a satisfactory fit of the template, we traced the shape to new core. We selected a sheet of 3/4" Penske board. Penske, properly known as Airex PXc board, is high density urethane with glass fibers mixed in for reinforcement. A sheet of Penske is structurally strong, shapes easily and is impervious to water. Unlike traditional plywood, this core will never rot! We managed two transom cutouts onto one 4'x8' sheet. Sandwiched together it will give us a total core thickness of 1.5 inch. To scribe the cut, we used a Festool Jigsaw. The jigsaw style seen in the picture is the barrel grip. I prefer this style to the traditional top handle for lightness and scribing blind underside cuts.
We dry fit our core cutouts to the transom. A little grinding was required on high spots. We also trimmed the top to approximate the old core height - slightly less than the outside skin.

Now, I'd like to say removing the old core came off without a hitch- but I can't. We punched through the outside a time or two in the process and those need some touching up. A
proper patch would suffice, but we opted to bullet proof the transom with one layer of biaxial cloth. This will go in place just before the core installation. Biax, also called 1708, is great stuff for structure applications. But before you go ahead and jump on the biax train too, you may want to read on in future post to see how it worked with epoxy. These pictures show our cut of the cloth.

We used these electric shears to cut the cloth and man they're awesome. One of those simple things that makes life so much easier. A little battery powered gadget that sounds like an electric toothbrush. You can lay the cloth over a shape and cut it out without manipulating it and distorting the weave. If you have alot of cloth cutting to do, it's worth it's weight ten times over for the savings on damaged cloth!

The old Mako made a trip for the the next phase. We were blessed with access to a heated building in winter! The unheated warehouse posed a problem for resins to cure. Cold temps can be overcome by very fast hardeners in a pinch, but it's a give and take. Very fast hardener will accelerate cure in cold temperatures, but epoxy cures much stronger in temperatures above 60 degrees (the warmer the better). The cure strength is much happier in a warm workshop. Come summertime mother nature will take care of the heat for us, but for now this workshop is a blessing.

Before calling it quits for the night we did a few last odds and ends. We tried out the biax cloth for fit and made some diagonal slices to fit it into the odd corners. Next we etched the whole bonding area with a wire brush and course sandpaper to add a little tooth for bonding. We then cleaned the inside thoroughly with the shopvac. Placed a few bandaids with painters tape to show our sympathy for the wounds we had inflicted, then we filled all those old screw holes and damaged spots with thickened epoxy. Content with how things looked, we retired to our favorite pastime - standing back for a gam session with a beer in hand, talking about "what we should really do next is..."

Dissecting the Transom

2009-03-05T10:32:00.000-08:00

Installment 10 of TJ and Mike's Mako rebuild saga

In our last segment, we cleared out all the belowdeck flotation foam. This boat looks and feels lighter and drier. It was noticeable when we jumped aboard. The weight loss changed the trailer balance enough that we had to re-adjust the poppets bracing the stern. Now it's time to address the transom.

Our goal in this next phase is to cut out the wet core in the transom. We need to leave the outside skin intact to keep the hull shape - draw upon those old frog dissections skills from science class. After some discussion, we decided to also cut out the corner fish boxes. The old style boxes aren't really big enough to store anything, they're mostly shinbusters eating up valuable deck space. Admittedly, the heavy layup of the fish boxes added tremendous structural strength to the transom. But the stress cracks in the corner joint needed addressing regardless. We'll build a little extra reinforcing to make up for the loss, but the end result will be alot more usable deck space.

For precise cutting we used a Fein Multimaster with HSS Saw Blade. This tool is great for digging in odd corners and angles. But for this task it lacked the muscle to power through efficiently. The beefier Fein Supercut might have torqued through this material easier. Some advantages of the multimaster you just can't beat- it is light, easy to use, and will do things other tools simply cannot. But this isn't one of em.

After what seemed an eternity of carving out the score lines to pop off the inside laminate, the blade of the tool heated up too much and shattered. Perhaps there is a better tool for this work.

We grabbed a tool with muscle. The Dynabrade Cut-Off Wheel cuts a 1000 times faster than any reciprocating tool, but still is easy to control. The shape is more challenging to squeeze into contours, and impossible in some tight spots. The cutoff wheel also requires a compressor with a little bit more umph to power her (21 SCFM max). Because our compressor was a little shy on airflow, the tool would bog down once the cutting edge was buried. Frustrating, but still much faster than the multimaster alone for this job.

With our cuts completed and the March night mercury dropping to hand numbing levels, we retired for the week.

The following Wednesday we began the most tedious of all tasks- removing the inner fiberglass skin and every last bit of plywood bonded to the outside skin. The inside laminate came away without too much effort. Removing the newly exposed plywood was tougher, much tougher. The wringing wet plywood was still heavy and dense. The plywood must have been a good marine grade to have held up intact while soaking wet all these years. The challenge was to remove the wood without destroying the outside of the hull. We set to the task with chisels, pry bars and some heavy hammers. But prying would certainly crack through the outside of the transom. Instead we chiseled and chipped away. It took what seemed an eternity, like "sailing from tedium to apathy and back again, with an occasional side trip to monotony." Plywood is made of wood pieces or veneers bonded together in layers. It did not respond well to a chisel. Separating plywood bonded to fiberglass made for slow going. This job took us two complete nights of work.

Take a load off...

2009-02-12T14:00:00.000-08:00

The next installment in the continuing saga of a classic Mako runabout rebuild

After hacking away at punk flotation foam for awhile, we assessed the situation and our process. All this foam is no fun - in fact it's hard work. This picture shows better how wet this stuff is. It's mind boggling, since this boat has been dry for years. The boat was covered under a ventilated tarp for 3 years and then sat in dry storage of the warehouse for another 7 months or so. It's still soaking wet! The only way to truly dry it, short of ripping everything up, would be some decent holes ontop the deck to evaporate water out. But we don't want to wait and hope. We're taking it all out, saturated foam gone once and for all.

This is the way to do it - after struggling for a while with big pry bars, we came across a couple of shovels in the building. Flat nosed garden spade shovels would probably work best; we used what was on hand, pointed long handled shovels. As we picked up steam the foam kept a rolling- so fast that it meant constant trips to the dumpster. And these buckets of water soaked foam were not light either. Good tunes kept us motivated as TJ scoured out foam from every corner and I trudged between bright work zone and the quiet, cold winter night darkness of the dumpster.

A few hours in and things were beginning to clean up. We shoveled the ankle deep rubble into big trash cans. Now the stringers and hull began to peak through.

The foredeck area was perhaps the one spot of the boat in good condition with no soft spots. Nonetheless, we opted to cut this out as well. We want to evacuate as much wet foam as possible. Also, as we exposed more of the stringers, we conclusively agreed they desperately needed some TLC. With foredeck extracted we could access foam, stringers and main deck installation. TJ and I also agreed it may be nice to include a foredeck locker in the rebuild. Since the deck is in good shape, we're hanging onto the piece we extracted.

Now that looks much better. We even dug out any accessible areas below the gunwales. Any foam that felt dry to the touch on top was always wet on the bottom when we popped it out. It was particularly built up around the stringers as you might imagine. Improved design will certainly include some limber holes through the stringers to let the moisture drain into the bilge and out.

I wish we could put this dumpster on a scale - I bet we pulled out a between 500-1000 lbs out of that boat in just foam. It truly filled about 3/4 of the dumpster in the above picture.

Foam Foam go away...

2009-02-12T13:30:00.000-08:00

Would you look at this mess. But wait, before you do...

If you found the repair video of last post helpful, here is the final half of West System Fiberglass Repair video. The West System steps outlined here are a proven successful repair method, one of many possible approaches. In any repair, proper preparation of the repair area takes the most time and is critical to repair strength. If you have never done this before, do some research beforehand, but fear not, it's easy when done properly.

In all fairness, this repair could be done more cheaply using polyester resins instead of epoxy. (See Epoxies, Vinylesters and Polyesters Explained) We selected epoxy because we are familiar with it, like the working characteristics of epoxy, better strength to weight ratio of epoxy and it isn't as stinky when the stuff kicks. Any polyester gelcoat finish will stick just fine to properly cleaned epoxy (soap and water scrub to remove amines). This was a great boat made of polyester, and it will be just as good should you choose to use poly resins in the rebuild. Whichever your tool of choice, just make sure you follow the proper preparation and mixing procedures. The West System Fiberglass Boat Repair and Maintenance Manual is a great resource for exactly this type of project. Now, on with the story...

With the old deck removed, we peer into black box. What lurks below decks is cruddy foam galore. Mako filled mostly all the void areas with 2 Part Flotation Foam. This closed cell foam serves many purposes. Foremost, it adds needed buoyancy should you wish to invert the boat and make it a life raft. ;) Additionally, the foam has structural purpose. Some boat designs seat the deck directly atop the stringers (fore aft longitudinal supports). The Mako deck instead is suspended. Smaller longitudinal supports are bonded to the underside of the deck, and the whole thing seated on a bed of foam. The foam cushion deadens shock when pounding through waves.

It almost looks fluffy and edible in the above pictures - some salty fluffernutter sandwich. But here's the rub- all this foam is soaking wet. Closed cell foam normally does not hold water. But even this most synthetic of foam degrades with age and exposure to elements, in this case good old H2O with a dash of fuel and twist of mildew. Dead flotation foam born again into a giant sponge. Cool! Remember those eerie groans and pops the winch cable made as she was guided home on the trailer. That's one heavy boat! If you suspect this may be a case in your boat, check the waterline. The yellow tell-tale waterline on this old girl grew higher and higher. Tall tale perhaps (sorry, couldn't refrain from the bad pun), but I suspect there was a time or two she was floated up from the bottom of some bay. There's alot of water in here.

So bring on the unsavory nasty task. We have to pull and rip all this foam out.

First we tried to lever chunks out with pry bars. It worked a bit, sort of like shoveling snow with a teaspoon. The foam clings to the hull, so is takes some elbow grease. Occasionally we'd celebrate a particularly big chunk that would pop free. Maybe even show it off boastfully til a bigger one came along.

But mostly, the big prybars made wet, mushy pulp freed up between the stringers. (and yes, that is a big ol crack in the stringer pictured above. "Dem bones weren't made to carry all that water Cap'n")

We need to change tacks to make any decent progress.

"Off with her Head!"

2009-02-05T13:02:00.000-08:00

Time for the ceremonial first cut - Would the person responsible for the derelict white power boat please step forward... It's a funny feeling when you actually hold a saw over any boat with malicious intent. We're about to make every boat owner cringe - literally cut the top off this boat. Once we do, there's no turning back. TJ and I comfort ourselves by agreeing, "well, we can't make it any worse!" So here goes nothing - we grit our teeth and plunge in.

See, it's not so bad. Just like a friendly dentist visit ;)

Our basic plan with this cut is to leave a flange of at least 4-5 inches of remaining deck. The flange will provide area needed to tab the new fiberglass deck into. Check out the West System repair video to get an idea of basic fiberglass repair principles...

We will return to the flange of remaining deck at a later date to prep it for laying in the new deck.

The Sawzall rough cut through the old polyester fiberglass deck handily. This reciprocating saw is a great cut anything tool but beware - if you plan on keeping stringers and all intact for re-use, be careful in the depth of cut. Or you may unwittingly cut through stringers and other structural members unseen. It was challenging to contour the 90 degree corners with a Sawzall. If you plan on re-using the deck later, a jig saw will make a consistent, cleaner cut at a controlled depth, thus it may be a better choice.

Dirty Surprises...

2009-01-29T13:35:00.000-08:00

So far TJ and I have pulled the console and outboard off this Mako 19. Decks are cleared for some destructive fun...

With console removed, we pulled the screws and pried up the deck panel covering the fuel tank. Some good pry bars were needed to break the sealant/adhesive bond securing the panel.

The aluminum tank was as expected, a mess. It looked as if it washed up on a beach then spent a few years beside a dumpster in some alley. The good news - it appears sound, no leaks. From first glance we have two options. Option one - send it out for professional cleaning with new fuel pick up and sending unit installed. Or option two - replace with a new tank of similar dimensions. We are favoring the complete replacement. Why? Because it's the easiest way to ensure good fuel (til they finally perfect the hydrogen fuel cell outboard ;)

We cut the last umbilical - fuel fill and supply hoses - and pulled the tank. From the stale fuel smell wafting from the bilge, it's obvious these hoses failed some time ago. We are likely looking at original fuel hose from circa 1970. Bad fuel tanks below deck are common in classic Makos, Seacrafts and Whalers of this vintage. The quick fix is simple. Just throw an above deck tank on deck and forget about the mess in the bilge. But since the decks are coming up next, it makes perfect sense at this stage to ensure any engine is fed good, clean fuel.

Pausing with the fuel tank for it's final goodbyes to the old Mako, we pitched it over the side. We're now ready for some reckless fun with the Sawzall as we cut out the sore spots.

Engine's Aweigh

2009-01-22T11:00:00.000-08:00

Picking an outboard engine off the transom is easy enough in practice. Just grab it by the lifting ring next to the flywheel and hoist her up. But stick a boat in the tightest corner of the warehouse, surround her by other boats and storage shelving, then block her up so she can't move. Now you see why we stand there dumbly scratching our heads. Not so easy now is it.

Eureka! We've got a giant garage door behind us. Just open the door and drive the fork lift around. Wait, there's a foot of snow blocking access to the door. Get out the shovels. Now this door doesn't want to open, blocked in by snow and frozen ice runoff from the roof. Persistence, persistence. This simple process which should take a matter of minutes takes us the better part of our Wednesday night session.

Worn fork lift tires are certainly not made for snow. We clear away enough snow to maneuver and push the old fork through the ice patches til fork is aligned directly over lifting ring. We doubled a stout double braid nylon line as a harness and hoisted her up slow and steady.

As the hours grow late and freezing cold has long since taken all feeling from our fingers, the fork lift is powered down, the sound of the tunes blaring once again dominate the warehouse. The old Evinrude is snugly lying atop a pallet.

What's First To Go?

2009-01-15T08:48:00.000-08:00

TJ and I assembled on our first night of action with the big question, "where to start?" Let's start at the top. This console needs to go. Not as bad as we thought, unzip all the deck screws from the decaying teak trim ring- done.

Unhook steering cables- check

Throttle control box- got it

Now how do we squeeze the fork lift between these boats to pull this thing off?- to which TJ politely motions to me- which if vocalized would sound something like "out of the way little man." From the squatting deadlift position he gives a heave. It's cold in this place, unheated warehouse in January. New England weather gave us a hell of a time just getting the front door open with the iced over snow drift blocking the way. As TJ heaves you can see every breath, the seal clings momentarily and then pops as ancient adhesive goop parts (undoubtedly 5200). The console begins to clear the deck. Taking the cue I join in - this is actually pretty light once it's unstuck. We walk the boxy console to the transom to unship it.

Suddenly this boat seems a whole lot bigger. Now for the engine.

Clear the Decks for Action

2009-01-07T08:09:00.000-08:00

After a harrowing extraction from the woods of Cape Cod, the Mako 19 now sits happy and dry in the workshop. The tarp retired, it's time to clear the decks of all debris. It's amazing how much stuff one can conceivably store under the tarp of a 19 ft boat. "Hey, I remember this mooring rig, man I really could've used that last year." "Oh cool, my old Craftsman ratchet." "Hey Dad will be happy I recovered his best shovel." Slowly the detritus of lawn debris and nameless objects is cleared away revealing what resembles a boat deck.

With the decks clear, the Jolly Tinker once again reclaims her identity from storage bin to boat. In this new light, our motivation begins to gather way.

"What We've Got Here..."

2009-01-02T12:09:00.000-08:00

Well, looking at her from a distance, it's not so bad. Ballpark guess, it's a 1969-1973 Mako. See the mustard yellow non-skid. Low wide notch for the outboard. A real classic. The days when polyester glass was laid up with abandon. The hull is sound- never mind the holes and 5200 repair spots everywhere. Stand back. Squint you're eyes a little. Fresh coat of paint, some epoxy here and there, repower and redo the console... now you're with me. Looks pretty nice doesn't it. Now bring you're eyes back into focus and step closer. Holy Mary Mother of God! Is it supposed to make that crackling sound with every step? I like how the deck sinks in when standing at the helm- is that to absorb shock? Very funny- Don't panic. Remember we can fix anything, so long as you're a stubborn mule who likes a grinder and staying up all night.

"Jolly Tinker" maybe we'll keep the name?

This boat has seen it's share of patches!

Not my first choice for placing a battery. I mean really, who decided this was a good idea? Lots of these Makos seem to have the same wound.

Vintage!

Where to Begin

2009-01-01T11:33:00.000-08:00

Some ideas are gifts, others a burden. This project boat, well, only time will tell the difference. The lightning bolt inspiration struck many years ago while cruising the classifieds. The perfect old boat for sale. It had been festering like a side yard sore under blue tarp for many years since. But the time has come, either set aside childish dreams- or make this project happen. So with renewed boldness and confidence, two men trudge forward in the evening hours after work with sawzall in hand and a plan in mind.