78' StarCraft Tri Hull Rebuild

DerekG

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Mar 22, 2014
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50
That was my thinking as well. No sense in putting a hole in a perfectly good and sealed floor. On another note, I plan on installing all my wood components and filleting them in this weekend. Im a little worried about the next step of wrapping 1708 of the tops of the stringers. How large of radius have you used on the top of the stringers. Also i wondered about using 3 layers of 1208 in the hopes it conforms a little better.
 

DerekG

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Mar 22, 2014
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Found another thread where you already answered my last question. Since I wont be wrapping it over the top I will stick with the 1708. Seems pretty tried and true with everyone on here.
 

DerekG

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Mar 22, 2014
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So I have made some more progress on the trihull. I have my transom glued to the outer skin with peanut butter, stringer frame installed and filled as well as taking care of a small problem along the way. I forgot to take pictures of the transom being clamped but basically clamped a 2x4 on edge across the top and then screwed a board to the new transom through the drain hole to hold the bottom. probably wasnt the best solution to clamp the bottom as it cause a void between the transom and outer skin in one bottom corner. I will get to that in a minute and how i fixed it.
Transom fillets
transom fillet.jpg

For the stringers I mixed up some PB and put it in a gallon ziplock bag and cut the corner off. I put a heavy bead down the bottom of each stringer and then set it in place as it naturally layed with a wiggle or 2 to help it squeeze out the excess. I smoothed out any squeeze out with a spoon and let it set for an hour before doing all the fillets.
stringers set.jpg
So this is the void i was talking about...tapped around with a screw driver handle in a grid pattern to determine where exactly the void was and how big it was. Everything fit tight around the edges but I think it was a lacking of clamping the bottom corners on my part.
transom void 1.jpg
So I came up with a plan to fix it and did just that. I ended up using a hole saw to cut 2 1" holes in the outer skin only. Then I used some tape to make a sort of funnel to pour the resin into. I only filled in one hole but drilled 2 so the escaping air that was being replaced with resin had a way out. Also pushing in and out on the outer skin helped make sure I had filled the void completely. after it hardens I will just sand them off flush and paint over them.
void fix 1.jpg
I also picked up 2 sheets of 1/2" acx exterior grade plywood for the floor and got it all fit into place. After that I sealed the bottom side with a layer of 6oz fiberglass cloth and dry fit them to make sure the extra thickness hadnt cuased any problems. When it all gets glued into i plan on using SS screws every 2 feet and at the seam to ensure good contact and squeeze out of the PB.

floor fit.jpg

I have a few more things to work on with making the outboard mounting holes in the transom watertight but I will work on that through out the week while I wait for what i hope to be my last shipment from us composites to arrive. I plan on spending all day Saturday getting all my remaining fiberglass cut out and layed up. 4 gals of poly resin and about 15 yards of fiberglass...should be make for a long but productive day. If any of you have any question on of the steps Ive shown dont be afraid to ask. I can tell you every detail of how i did it and im sure there are more than a few here that can help you even more.
 

DerekG

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Joined
Mar 22, 2014
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So i have made tons of progress this weekend and can see a splash in sight. When i left off i had the stringers set and filleted with PB and my floor dry cut to fit. I worked for about 9 hrs yesterday and 7 today in 90 degree heat...but i dont regret a minute. I started by wetting out 2 layers of 1708 on the transom to seal it and tab it into the hull, 3" on the first layer and about 5" or 6" on the second layer to make sure it had plenty of area to grab onto the old fiberglass. I used 2 layers of 1708 with poly resin down both sides of the stringers. The first layer went about 5" onto the hull and the second about 8". I didn't wrap any over the top of the stringers since I used and heavy bead of PB to glue the floor down and held tight with SS screw.


So once I had the floor down and gave it about an hour and a half to dry I started drilling my holes to foam the hull. I used 2lb density expanding foam from us composites.I started mixing 1 quart of part A and 1 quart of part B for a total of a half gallon of mixed foam. I ended up using all of their 16lb kit with all the voids filled and plenty of over flow out of the holes. I figured 8 cubic ft and poured it just before dark so it was about 75 degrees. Temp makes a difference on expansion rates but that's all covered on their website. I let it set for about an hour and used a 6" drywall taping knife to cut the overflow off flush. Sprayed it with Pam before and nothing stuck to it.

This morning I started by cleaning the whole floor with a sander to remove foam and vacuumed clean the whole boat and wiped down the fiberglass with acetone. Then I layed out both layers of 1 1/2oz CSM, extending onto the hull by 3" for the first layer and 6" for the second layer.


After everything was layed out and cut to size I draped the second layer on the right and the first layer on the left so as I worked I always knew i was grabbing the right piece for the right layer. Also since it was around 90 degrees i cut my MEKP ratio by %50 and worked with 1 1/2 quart mixes each time as i went and even that was a lot of work to get everything wetted out before it started to gel. would definetly go a quart at a time if i had to do it again. Also completety wet out on section before moving instead of trying to get the whole piece covered and then rolling it out. If it starts to gel its no big deal to mix another quart and continue where you left off, rather than have a partially wet piece of glass that wont take resin because its gelling.
 

DerekG

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Mar 22, 2014
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Here is where it starts to look like a semi finished boat. Before replacing the cap I screwed a strip of 1/2" plywood around the top of the hull to replace the split fir strip that was there. Once I got the cap set in place and started lining up the hole i realized i had some warping in the hull......not what i wanted to see. It was looking great at the back and on both sides until i got to the front where the cap appeared to be 3/16" shorter than the hull. So I started where the screw holes lined up on the back and worked my way evenly down each side till i got to the front where it was now lined a little better but still not slipping over easily. So with the help of a couple putty knifes to get it started and a ratchet strap to pull down on the front point of the cap it finally slipped into place. Then I went back and installed the aluminum rub rail and called it a well spent weekend and a much needed shower and a drink.
IMAG0230.jpg IMAG0233.jpg
I had thought I had made a "goood enough" cradle to hold its shape but i think i got really lucky that i was able to get the cap on at all. So if someone suggests in the teardown stage to build a cradle for the hull for the duration of the rebuild I would advise you to take their advice and not have the close call like i did or worse. cutting out everything to make one.
 

DerekG

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Mar 22, 2014
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One more thing about how the hull flexed. It didn't bow out on the sides or have a twist to it. Its like the hull flattened out length wise at the bow.
 

DerekG

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Mar 22, 2014
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So I got all my touch up painting done where it got scratched in the rebuilding process and the outboard is back on with the holes sealed. One step closer to the water. Picking up a couple brass drain tubes this weekend and making a flaring tool on a lathe so i can knock one more thing off my list.
 

DerekG

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Mar 22, 2014
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So I finally got the flaring tool made and the brass drain tube sealed and done. Temporarily hooked up the steering throttle and put one of the old seats back in for testing. Found a spot at the edge of the sand pit behind our house and finally got it in the water for a test of the main components. Well worth the wait. It was just big enough to hit about 30 or 35 mph before i had to slow down and i had forgotten how quick it got there. It went like hell after trolling around for a while. The new seats and bedliner for the floor should be in later this week so until then i will be working on upholstery for the cushion that go around the peremeter of the boat as well as building a bench seat and reusing the foam from the old seats for that. Also box bases for the new seats. Then wire up the lights, radio and bilge pump and leave the trailer as is till this fall to sandblast and repaint. Should be done just in time for our camping trip to Waconda Lake in the middle of august.
 

DerekG

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Mar 22, 2014
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splash.jpg

After some quick testing and a little much needed break it was time to finish the last stretch of the project. With the floor all cleaned and wiped with acetone I started rolling my Grey Herculiner on the floor.
glassed floor.jpg finished floor.jpg
I also decided to do the floor in the bow area just because i had plenty left and it was always a little slick before. Also i went ahead and stripped the foam from the old seats and reused them when building the new bench seat. I also reused the aluminum hinges so the back rest flips forward enough to switch fuel tanks and hook up a battery charger if needed. When i need to refill the tanks the whole bench is held in place with a wing nut on each end and can be slid forward for access to everything in the bilge area.
 

DerekG

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Mar 22, 2014
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So here are a few more detailed pictures of how the bench seat is mounted. I built the bench seat and base and positioned them right where i wanted them, made a couple marks on the sides of the hull and glassed a wood block on each side with 1708. After that everything got covered in outdoor carpet and a lag bolt with a thread stud was screwed into each block with a little sealer on each one.
mounting block.jpg
The front of the bench seat is 3/4" BCX ply painted with exterior paint to seal it and covered in carpet to finish it off.
bench mounted 2.jpg bench mounted.jpg
There is a 1/2" gap on each side and about an 1/8" gap on the bottom to let any water make its way back to the bilge area to be pumped out.
 

DerekG

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Mar 22, 2014
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The 2 front seats got similar treatment for mounting. I started by building a plywood box for each seat and cut them the tallest i would ever want them to start, placed them in the boat with the seats on them and kept cutting a half inch at a time off the bottom till they were just right. I marked the location on the floor and glassed 2 blocks under each seat box before rolling on the bedliner over the entire floor and bilge area. The blocks were sealed with resin and the seat boxes were painted with rustolieum exterior door paint to seal them from moisture. They were then covered in carpet using 3M spray contact adhesive. The seats were mounted to the box from the bottom first and then the whole unit was slipped over the blocks on the floor and screwed into place with SS screws while leaving about an 1/8" to 1/4" gap underneath for drainage.
seat box.jpg
 

DerekG

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Mar 22, 2014
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And my to do list is quickly shrinking.
-Mount and wire power to 6 switch panel on the dash
-Mount and wire bilge pump
-Install new glove box
-Mount stereo head unit and speakers
-Wire bow and stern lights
-Mount and wire red LED strips for seeing your fishing gear at night
-Check wheel bearings on trailer

Only 12 more days till its first real voyage of a weekend of boating and fishing. Plenty of time as long as everything shows up this week.
 

DerekG

Seaman
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Mar 22, 2014
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So I finally have everything finished except im still waiting on my rubrail insert to show up. Took it to Waconda Lake in kansas last weekend and it performed great! Plenty of tubing, exploring coves and a little fishing in the evening. Taking it to the girl friends parents this weekend to do some fishing with her dad on a lake and a few canals in south central nebraska. I did run into one hang up before our first outing....trailer lights. Yep those darn things. Ended up putting on new led lights, wire and connectors on the trailer in the dark the night before our first trip, but they worked great and i never worried if that car behind me could see that i was braking or merging. I will be adding a few more photos before moving this thread over to the completed projects area. If anyone including an admin would care to inform me on how to move the entire thread it would be greatly appreciated.
 

Woodonglass

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Dec 29, 2009
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25,924
DerekG,

You Did some really fine work on your project and Turned an Ugling Duckling into a SWAN!!! For that...You get one of these...

 

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Love what you're doing with the boat, looks awesome! Really good attention to detail on your work.
Let me know how that paint holds up, as you know I'm restoring the same boat as well and would like to redo the hull next year :) Similar to what you have done.

-M
 

DerekG

Seaman
Joined
Mar 22, 2014
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Thanks Wood that really means a lot. And thanks again for your guidance along the way. It was a great weekend get away in the new boat but after a few more outings at local fishing holes im having gear engagement issues in the lower unit. Tore it apart and looks like all the gears and shafts are fine but the seals look like they froze up and melted the plastic races and ended up with metal bits under the shift rod causing it to not go into gear. Looks like a cheap fix just a pain to clean and reassemble.

Monnewbie3, so far the paint has held up great but did take a long time to harden. I think that was an error on my part and not the paint. For the primer i did 2 coats but got a little caught up in getting complete coverage in the first coat and using the second coat to add thickness. Big mistake, it did end up working out but it took over a week for the primer to get nice and hard (no longer scratched with my fingernail). If it takes 3 very light coats over a 48 hr period with a day or 2 to dry i think you will be much better off. As far as the paint goes, same thing, dont worry about complete coverage but rather doing 3 thin, and there for fast drying, coats rather than a thick coat that will take forever to harden properly. Mine took close to a month to get a nice hard finish that was scratch resistant. Just be aware that there are time limits on applying additional coats without roughing the surface before each additional coat. As far as the 2 tone goes or masking off any new paint, make sure it has a nice hard finish before applying any tape and use a low adhesion tape. Most painters tape have it marked on the roll what adhesion level it is. If the paint isnt dry enough or the tape is too sticky it with mess up the glossy finish. Then the only fix is to smooth it a bit with a purple scotch brite type pad and live with he more dull strip or lightly sand and respray the affected areas. Hope my mistakes can help you out on your boat. When the going gets tough just remember the feeling of the open water in a boat you know inside and out. Good Luck.
 

Woodonglass

Supreme Mariner
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Dec 29, 2009
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25,924
Soooo, How's that Truck Liner Keel Guard working out?? Would you recommend it to others?
 

Tnstratofam

Commander
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Aug 18, 2013
Messages
2,679
I just wanted to say great job on your resto. I'm interested in how the truck liner worked for the keel guard as well.
 

DerekG

Seaman
Joined
Mar 22, 2014
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50
it hasn't had a ton of use on it yet but so far its held up great while beaching it. no bubbling or peeling on any part of it, that was my main concern.
 

DerekG

Seaman
Joined
Mar 22, 2014
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50
I’m back for a 5 year review of the Herculiner keel guard. Aside from a couple small scratches that exposed the paint underneath it has performed extremely well. It hasn’t hardened or gotten chalky. Would highly recommend it.
 
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