Fuel tank replacement

[clop52]

I was researching materials i can use to replace the Marine plywood that rotted out and found coosa board. Any thoughts or recommendations on this subject? I'm hoping to have the boat in the water running in two weeks and there are still a few holes to fix. I took out a lot of the wood frames on the hatches around the center console. Call me new fashion, but i prefer plastic (mostly because it does not rot ;) ) Boat outfitters have a lot of good choices like built in tackle boxes and custom made hatches. Anyway, im getting sidetracked, Coosa board? Yay or nay for a 69" x 23" deck cover to cover my fuel tank. Thanks!

[RickK]

Maybe I'm getting confused, have you decided not to just recore the existing cover?  That's the easiest way. You can use plywood and coat it with resin to seal it (some people put a lot of saw kerfs in it to really let the resin in) or you can use a composite.  But use the existing hatch cover, beef it up a little with new glass and then add the core and glass over that.

[Que Pasa]

coosa is good stuff, but you may want to use a support so it doesn't sag in the middle.

[clop52]

Rickk, yes i am using the existing cover. I just scraped off the old glass and plywood.  I am getting some coosa board tomorrow (thanks QP) and i did not know what to do after that.  So, you recommend I reglass it first, then put the coosa board and then glass it again? Never done reglassing, so i'd be a little apprehensive, but always up for a new challenge.

[RickK]

Take a 4" angle grinder with a flap sanding wheel (40 or 60 grit) and grind all the old residue down to old glass (try not to grind through).  Now place the lid on a flat surface that is covered in plastic and laminate 2-3 layers of some 3/4 oz chopped mat onto the bottom of the lid. Use a cheap 3/8" nap roller cover from Lowes or Home Depot. Go right over the holes that are in the lid. You can use poly or epoxy though epoxy doesn't work as well with chopped glass, it doesn't melt the binders holding the mat together.  Let that harden and then lightly grind it to rough it up and give it "some teeth".  Cut your coosa  about 1 1/2" inches shy of the edge all the way around and cut the edge at a 45 degree angle to remove the sharp edge so cloth will lay down easily. Mark the outline of the coosa on the lid. Mix some resin with cabosil to thicken it up to peanut butter consistency and then using a trowel with 1/8 or 1/4" notches, cover the lid tot he line drawn and then set the coosa in the resin.  Weigh it down with cinder blocks or whatever heavy thing you have laying around.
After that hardens (overnight doesn't hurt it) then it's time to cover the coosa and to the edge of the lid with 1708.  Roll poly or epoxy on the cooza and lid, lay the 1708 into the resin and then use a hard roller to press it into the resin and roll out air and then using the nap roller, make sure the 1708 is saturated but not flooded.  After that hardens you can flip it over and cut out the main hole again. If there is anything that needs to be filled and faired on the top, now is the time to do it.

[clop52]

Thanks so much! That is a very descriptive, step by step directions.  It puts me at ease for sure.  I'll be doing all that this weekend (weather dependent).  He are some pics of today's work.  Chiseled out some bigger chunks after i let them dry on the hot sun all day and sanded the first fourth part of the lid. I used 60 grid with a 4" angle grinder. It took me five minutes. 

[clop52]

[clop52]

[RickK]

When you start the lamination part make sure you support the entire length of the lid and make sure it is flat (like on the driveway with plastic under it).

[clop52]

Gotcha, thanks Rickk.  I should have everything i need this weekend.  I'll keep you all posted. I'll go West Marine and get some poly resin and the hard roller. I have already ordered the 1708 and chopped mat from Amazon and should be here tomorrow.  I picked up the coosa board today.

Question, you referred to poly and resin on your post as two separate materials. Are they the same thing? Are the two words interchangeable? Thanks again for the help.

[Levi]

Where do you live? Google "fiberglass supply " and see if you have a supply house near you. Chances are good that you do and it will be MUCH cheaper than Worst Marine besides last time I looked they had 10X more Tommy Bahama  fabric than they had fiberglass fabric

[Levi]

And yes Rick and most other people interchange resin and poly - usually if it's something different like vinylester or epoxy we specify that. Poly will be fine for what you are doing though cell-tec or any of the other expanded PVC boards would hold a screw and be about half the cost

[Woodeneye]

Update!!! So, Phil from AMW is phenomenal!!  He was completely understanding of my situation and charged me less ( a lot less) for a new tank.  I have had some people interested on buying the oversize one, so i am happy!

Phil even put a rushed on it and i got late last week (5 days turn around!).  So, here it is...the final product:



It fits!!

What a great result. I'll be sending my business Phil's way when I get around to replacing my tank. Thanks for the update.

[clop52]

Im getting there, guys.  Connected all the fuel lines, filled up the tank (38 gallons!) and ran the engine...and it ran!  Had some minor wiring (grounding) issues with the sending unit, which were resolved and she works!

Also, sanded the lid down to its core with a side grinder. Purchased all the materials and cut the coosa board to measure 1.5 inches from the edges of the lid.  Cut the edges of the coosa board at a 45 degree angle.  I came a little short on one end, but i can add some more coosa since i had some scrap left over.  I will start the glassing this week and will post more pics. Almost there, guys!

[clop52]

Coosa board measured and cut.