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My 1976 Mako Restoration

Old 12-03-2017, 07:13 PM
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ore is in. I mixed 48 oz of resin and hardener with an indeterminate amount of West Systems 404 thickener and about a cup of chopped strands. I probably could have used less strand and more 404 in my mix but by the time the consistency got close, the mixing cup was getting hot as shit so I went ahead and spread it. The volume was just about right for the surface area but it was kind of a bitch to spread, and I think the strand length is the main reason why. Oh well, its in. The clamps worked great but I'm pretty sure the bilge hole rod will have to be cut off and drilled out as my visqueen release barrier failed there.



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Old 12-03-2017, 07:14 PM
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I took the braces off tonight. Using a hammer to tap on the outter skin, most of the bond sounds solid but there are a couple areas that are definitely hollow with no connection. Two are on the very top edge and I can gravity feed un-thickened resin into these gaps. At least two more are in the field of the core but are only ~3-4" in diameter so I can grind them out locally and spot repair. The bottom bilge hole rod came out easily enough.

Then I overdrilled all the holes out and backfilled them with thickened resin. This time I tried just mixing the 404 high density filler with no chopped strand. This spread and worked much easier all around. The holes are pretty heavily overfilled and will require grinding to flatten out but that's the easy part. Then I began filling in the gap between the core and sides of the hull. You are supposed to create a radiused fillet on interior corners to allow the glass mat to gently flow around the turn. Bending the glass over or into a sharp corner breaks the strands and compromises the strength. To inject the thickened resin some people just do the best they can with stirring sticks and glopping it into the gap and some people use tubes like a caulking gun or cake icing bag. I decided to try caulk tubes. West Systems sells empty 10 oz tubes for stuffing your own mix into but they are like $5 each. A full tube of latex caulk from Lowes is $2. About 3 minutes with some hot water and a metal rod cleaned all the caulk out of tube and prepared it to be sacrificed to the epoxy gods. I used one of the West Systems tubes for a batch tonight and it worked well but only did about 1/5 of the area I need to fill in and they aren't reusable. Will get back after the fillets and start fitting stringer knees tomorrow. I am waiting on my next delivery of epoxy resin before I start the interior transom layup. I need to cut my matting out ahead of time since it will be 7 or 8 layers of glass and the layup will be time sensitive as I will be making each layer a wet-on-wet bond for a stronger chemical connection.
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Old 12-03-2017, 07:15 PM
  #23  
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I got all the matting for my inner transom skin cut out yesterday and this morning. Much more tedious than I expected. Six layers of 1708 and one layer of 34 oz tri-axial cloth. Should end up around 5/16" thick. This is significantly thicker than necessary but I'm erring heavily on the side of caution for three reasons;

A) Bracket. The motor will be hanging ~30" off the transom. That's a lot of leverage.
2) Four stroke. Most 250 hp four strokes these days weigh around 600 lbs.
D) Inexperience. Since this is my first time working with glass, I'm sure there will be small errors here and there.

Getting my next epoxy resin order today and plan on laying everything up on Sunday.

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Old 12-03-2017, 07:16 PM
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Got the inner transom skin laid up today. Took almost 8 hours and three gallons of resin. My back is wrecked.

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Old 12-03-2017, 07:17 PM
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I got some more foam removed and the fuel tank pulled out. Most of the zinc chromate coating on the bottom of the tank stayed stuck to the foam underneath it. For being 40 years old, this tank is in fantastic condition. I haven't found a single pit anywhere on the exterior of it. I'm still going to replace it though as I have no idea what the inside looks like and will probably add a little more capacity.



Then I drill the drain hole at the bottom of the transom. There has been some standing water in the back of the hull for a few days from a heavy rain but I wasn't too worried about it since the epoxy resin used on the transom skin is supposed to be indefinitely impervious to moisture. The top edge of the core is still open though as I still need to final shape it for the cap profile. I started drilling the hole and water started dribbling out of the wood. What. The. FUCK!?!?! Kept drilling and the shavings that came out are fucking soaked. I am beyond pissed right now. I don't see how any quantity of rain water could have dribbled down 30" of marine grade wood to settle at the bottom so I'm at a loss for how it got this wet. I'm going to drill out the through-hull fitting hole and a few test holes in an expanding radius to see just how wet everything is. If its only an inch or two then I'll just let it air dry for a few days and move on. Once dried, the holes will get backfilled with thickened epoxy resin and then re-drilled to the proper sized hole for each fitting.
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Old 12-03-2017, 07:17 PM
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I love these restoration threads. Keep up the good work and pics.

I am amazed at people's skills, ingenuity, and most of all, perseverance to conquer challenges and see these projects through to completion.
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Old 12-03-2017, 07:20 PM
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More cutting and grinding.



Got the inner port side stringer cut out. I'm using 8' long drop piece from the transom core so I'm not going to cut out the whole stringer at once. It will work out perfect as it has a turn down at the end that will serve as a knee brace to further strengthen the transom when its all said and done. I will route a scarf joint into the plywood to make the joint with the next piece as strong as possible. As far as fiberglass layup is concerned, I am leaning towards 4 layers of 18 oz bi-axial glass. I haven't decided if I will use 1808 or straight 18 yet. People seem to be split each way.



I am definitely replacing both inner stringers because I am also raising them to support the deck. Originally, the deck was primarily supported in the middle by the expanding foam. This will make the whole boat more rigid. I would like to leave the outer stringers as-is and not mess with them at all but the core of the inner part I cut out was pretty shatty in a few spots.





This was the bulkhead between the bilge and fuel tank.



And the whole deck core on the port side was pretty much wrecked.



Just for perspective, all of the foam I removed between the previous and these pictures filled four 40 gallon trash bags.
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Old 12-03-2017, 07:20 PM
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Spent today fitting the port side stringer section and cleaning the hull up. Did a little more grinding then hosed everything out and washed the blush off the inner transom skin. Wiped the joining areas down with acetone, cut my scarf joint in the new stringer core and set it all up. Mixed up a 24 oz batch of thickened resin. Tried to use up my West Systems shit. Got it mixed up pretty quickly, then spread it onto the hull in good time. By the time I got back to the transom the shit had started to kick and solidified pretty much immediately once I got it on the transom. So when I tried to set the core, the resin was hard. Shit! So I called it a day and will grind all of that resin off and try again later. I'll probably get a quart of the West System EXTRA slow resin for the next attempt. I'm just trying to use this shit up at this point and I'll do the rest of the build with US Composites resin.
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Old 12-03-2017, 07:21 PM
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I'm trying to talk myself out of re-using the original fuel tank. As I mentioned above, it doesn't have a spec of corrosion or pitting on the outside but I don't have a clue what the inside looks like. It holds 70 gallons. I initially was thinking of bumping up to 100 gallon capacity but with a brand new 4-stroke Zuke 250 it looks like most people with similar setups get 3+ mpg steadily. For what I want to do, that *should* be plenty of range. The boat will be trailered so topping off after every trip isn't a problem. I would like to replace the tank out of general principal but $2k is a lot of cheddar that can be better spent elsewhere. If I keep it, I would definitely coat the exterior in coal tar epoxy, look into interior coatings and pressure test it at 4 or 5 psi. Thoughts?
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Old 12-03-2017, 07:22 PM
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Got the slow curing epoxy hardener in. Got screwed. Nowhere in the description on Amazon did it say it was a fucking munchkin sized container. Come to find out it is quite a bit more expensive than the regular slow curing resin and only comes in smaller containers. Ugh, guess I'll see how well this works and then use the US Composites resin for the rest of this shit.

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Old 12-03-2017, 07:23 PM
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Got the port side stringer knee section bedded. Saw a random tip somewhere online about chilling your resin and hardener before mixing to prolong pot life so I gave it a shot. No issues this time.



Mixed some strand in this time too just for shits and giggles. Used around 15 oz of thickened resin and wiped the excess off with my finger. No telling how long this shit will take to cure but I probably wont mess with it or shake the hull around for a couple days to be sure.

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Old 12-03-2017, 07:24 PM
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I got the starboard stinger cut and ground out this evening. The wood in this stringer was completely intact with no rot but it was wet in a few spots. Oh well, all coming out regardless.



I lost a chunk of rubber out of the backing plate on my bad dood 7" grinder. I was leaning on it pretty good with a 16 grit disk and the piece just flew off. I would have kept using it anyway but it was vibrating so bad I could barely hold onto it. So I finished grinding with my 4 1/2". The coarsest disks I have for it are 60 grit flap disks so it took quite a bit longer than the 7" but still got it done. There were quite a few more voids in the factory lay up on this side.

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Old 12-03-2017, 07:25 PM
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Did some more demolition tonight. I cut out the deck section from the front edge of the coffin lid up to the fish box and hogged out all the foam. Five trash bags worth of foam and shit came out. This was the grossest water-logged nastiness I've seen yet on the boat. There was what appeared to be a t-shirt wadded up in the pass-through hole of the forward bulkhead and a massive nest of the crazy-fast tiny ants. It smelled absolutely awful and the ant nest area of the foam was particularly water logged and super heavy. I cut out the bulkhead and it was almost completely rotted out. It looks like the shirt and ants nest had trapped rain water draining from the fix box for a long long time. Oh well, done now. I finished after dark so I didn't get any pictures tonight.
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Old 12-03-2017, 07:27 PM
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Finished removing all of the floor decking and 95% of the foam today. 8 forty gallon bags full of foam. All that's left is under the anchor locker and I'm not sure what I'm going to do with the casting deck yet so that can wait. I was going to try and bed in the other major stringer and knee today but I had to add a little more thickened resin to a low spot on the hull so it will go in tomorrow.

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Old 12-03-2017, 07:27 PM
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Starboard stringer is in. I cut it 6' long in order to offset the scarf joints of each stringer to avoid creating a hinge joint. Pretty uneventful.

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Old 12-03-2017, 07:28 PM
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Got the rest of the starboard stringer cut out then spent 6 hours on the angle grinder. This evening, I finished cleaning dust out and then filled in the old stringer and bulkhead grooves as well as a few voids in the factory layup.

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Old 12-03-2017, 07:29 PM
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Finally got back after the boat. Got another stringer section fitted and bedded today. In hindsight, I would probably bond the sections together outside of the boat and then bed them all at once. I think it would be easier and the finished product would be much cleaner. I could have also done a much better job fixturing the first two pieces while bedding. I've learned the epoxy doesn't have any tensile strength when wet so whatever you are bedding slides around freely. It required a lot more effort to hold shit in place than steel fabrication. This time I did much better.

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Old 12-03-2017, 07:30 PM
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Got the rest of the port side stringer cut out and ground down today. The amount of grinding a project like this requires is insane. Today alone, I probably spent about 5 hours on the 7" grinder with a 24 grit disk smoothing out the ~10' of stringer I cut out. I went through 3 disks and produced about 4 gallons of non-airborne dust. I rigged up a couple of box fans to try and capture as much airborne dust as possible. I taped a house air filter to the back of one box fan and positioned it at the front of the boat blowing forward so air would be drawn into the filter and another fan at the back blowing forward. I have seen a few people make a tent out of painter's plastic to further contain the dust but I didn't feel like going to that much effort so I just shut the garage door while I was working. The dust will wash off my truck.

I dicked up a measurement cutting out the frontmost starboard stringer section and it ended up short. I can still use the material for bulkheads later but it was a waste of a couple hours work. After that pissed me off I mixed up a big batch of thickened resin with strand and filled in a bunch of grooves and voids in the hull layup to end the day.
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Old 12-03-2017, 07:31 PM
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I have been using fumed silica and milled glass from System Three as thickening agents for my peanut butter resin. The one and only reason I am using it is that it is available via prime on Amazon. The first jug of each was a super fine powder that would swirl up with the slightest breeze. The silica comes in a big 5 quart jug so I haven't needed any more yet but the milled glass comes in 1 quart jugs so I ordered a second one recently. The second one came in all clumped up and curdled for lack of a better description. WTF? It also didn't turn the same opaque white while mixing as the previous stuff did.



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Old 12-03-2017, 07:31 PM
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Got another stringer section bedded this evening. One more short piece to go then they're done!

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