Fiberglass Advice Needed

[dbaja]

Hey all, pulled my fuel tank yesterday to discover the glassed in plywood it rests on has delaminated and need to be replaced and glassed back in.

I’m thinking about doing the repair myself, shouldn't be too hard but definitely need some advice. Tomorrow I’m going to cut out the plywood and buy the materials.

How would you proceed with this project? Prep work, fiberglass weight/sheet size, number of sheets, etc, etc

Im capable but a fiberglass newbie so all advice is welcome, thanks

Also, the coffin is in solid shape with no rot or damage to the stringers or bulkheads. My other question is should I reseal them coffin with something before dropping in the new tank in? Not sure if that’s necessary or common practice. Thanks

 

[warthog5]

Run a grinder down that seam with a 24gt fiber disc. Grind it back about 10in. Start with a 3in layer across the seam...Next a 6in layer and then a 9in layer of 1 1/2oz mat . Polyester resign....easy on the catilist....It's August....DO NOT do it in direct sun. You can lay each layer 1 right after the other.

 

[dbaja]

Thanks Warthog5, your always a wealth of knowledge. Just to clarify, after I remove the old pieces and grind back another 10” do I need to do anything to the new pieces of marine plywood before laying them down?

Also, do you recommend using marine plywood again? I looked into coosa board but I have to buy a whole sheet which is way too expensive seeing that I only need half that.

 

[warthog5]

I would not remove the older pieces "IF" they are sound quality. Just glass over it

 

[dbaja]

Unfortunately that wasn’t an option Warthog5. Yesterday I prepped the coffin and removed the damaged plywood support pieces, They had to go, they were completely soaked and as I mentioned delaminating from the water intrusion. Each piece was 10”x 48” x 1/2” “marine plywood”, although the underside appeared to be completely unsealed and raw wood. I can replace with the same but better sealed material or ???. I can get a quality piece of marine plywood for 60 dollars so that route is quite appealing.

 

[dbaja]

Also, decided to work on other things while my boats in “boat jail”. Finally installed some Seadek flooring I’ve been holding onto inside the cabin, Also have some for the cockpit but obviously need to wait tell the decking is done.

 

[dbaja]

What I pulled, unfortunately in a order to do the job right they had to be replaced.

 

[StrayDog]

Also, decided to work on other things while my boats in “boat jail”. Finally installed some Seadek flooring I’ve been holding onto inside the cabin,View attachment 33804View attachment 33805 Also have some for the cockpit but obviously need to wait tell the decking is done.

Flooring looks great. This is going to b one special Parker when you’re done. I don’t want to distract from this tank discussion but am very interested in your SeaDek experience. Plan to do the same.

• Did you or vendor do the template?
• Sounds like you are doing the install. No doubt, you obviously have the skills.
• My sq. ft.. would be close to yours. Ball park on cost?
• Happy with Vendor / rep you were dealing with? If so contact info?

 

[K/A]

resin both sides of the plywood another option Nida core but note it has cellular construction plywoods fine if done correctly 30 yrs

 

[warthog5]

If it's Fir plywood....Resign alone will not stop the wood from Checking....It needs a layer of glass... I've done experiments on this.

 

[K/A]

resin prior to glass