# What material for Gheenoe decks/floor?



## matt_baker_designs (Nov 27, 2012)

Coosa board or divinycell


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## MikeChamp12 (May 17, 2021)

Divinycell h80 3/8” or 1/2”. Ive been looking at this stuff too but I’ve never used or seen it. But the price is right


3A Boat Core Material T92.100 | AIREX 3/8 x 48 x 48 Inch Polymer Foam


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## BadKnotGuy (Jul 8, 2012)

5/8" Divinycell H80 with glass on each side (10oz. weave should be fine but you should check the Chris Morejohn Beryllium build thread for exact specs.) I would order the carbon-core equivalent - it will be easier on your wallet. The Divinycell build will be lightest but will cost substantially more because of the extra glass and epoxy you will need. I think Coosa would work too but would be unnecessary for that job. It will weigh somewhat more and cost substantially more. If you could find true Okume marine plywood locally to you that would be a great option too. It will take far less epoxy and glass. Going the wood route would hurt you eventual resale though. People are terrified of wood in boats thanks to years of effective marketing by mass production boat companies. "No wood to rot" actually meant "we can build them quicker using cheaper materials if we pop them out of a mold". If you go the wood route (only use true marine plywood) do 12oz. bi-ax tape for the seams, every surface coated in epoxy, and 6oz. weave for any wear surface that you would be standing on.


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## Mike Haydon (Dec 19, 2019)

H80 would be seriously overkill. H60 would be about $50 cheaper a sheet and plenty strong enough for decks. Where are you located? If needing to lay shipping that may change someone's suggestions. Using foam and glass would be the easiest to bond to your gheenoe and keep the weight down. Carbon core is a better priced product. Post some pics and where your located so we can help you out better.


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## j_f (Dec 15, 2021)

Thanks for all the responses, folks. @Mike Haydon I'm in New Orleans. I'm looking to build front rear decks like these:


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## Mike Haydon (Dec 19, 2019)

That's a fairly strait forward job. Just search johnson builds on here. You'll get all the pics you need. Search out carbon core and get some 1/2" foam core. 1708 , maybe 1.5 oz. Csm and poly resin. Put down the csm then a layer of 1708 with the finish cloth side up. Do this on both sides. Then cut your pieces out. Cut you some strips to tab it in and you'll be good.


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## sydngoose (Oct 1, 2017)

Either use 26 pounds Bluewater Coosa encapsulated ( top and bottom and sides) with epoxy ( thinned and painted on), then 1708 or 1808 : two layers on each side. 
OR
USE 3/4 inch marineply wood, and encapsulate that with epoxy resin then fiberglass.


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## Dobre (Nov 19, 2019)

Id go with 1/4 marine play or 1/2 foam core like divinycell. I cant get divinycell locally but found a green foam board here in Houston ive used and like alot. I believe its call Gurit kerdyn. and its like $75 for a 4x8 sheet. The gheenoeholics FB page has a ton of rebuilds there with alot of great info. some bad lol


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## j_f (Dec 15, 2021)

Dobre said:


> Id go with 1/4 marine play or 1/2 foam core like divinycell. I cant get divinycell locally but found a green foam board here in Houston ive used and like alot. I believe its call Gurit kerdyn. and its like $75 for a 4x8 sheet. The gheenoeholics FB page has a ton of rebuilds there with alot of great info. some bad lol


Yeah, at this point I'm leaning toward marine ply. I wasn't aware that I could go as thin as 1/4, but it makes sense given proper bracing. I might PM you with related questions if you don't mind. I'll buy you beers next time I'm in Texas (girlfriend is from there, so we make Houston and Austin trips fairly regularly).


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## nicholashoule (10 mo ago)

didn’t have access to marine ply so i used exterior plywood. i think it was 3/8 for the floors? don’t remember. closed cell foam poured underneath in that channel with the wood on top. lots of fiberglass added. floor doesn’t flex at all even going 25mph in chop


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## Cody Taylor (Nov 10, 2015)

Had a classic built just like that


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