# Composite deck?



## Boneheaded (Oct 4, 2017)

After some research decided to see what you think is a good call on a composite deck material, Im putting a front deck my jonboat, trying to find the right foam core or composite material? The jig is made up I’m experienced with cloth and resin. 
What are you guys using and who is a good distributor?


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## seapro17sv (Feb 3, 2015)

Boneheaded said:


> After some research decided to see what you think is a good call on a composite deck material, Im putting a front deck my jonboat, trying to find the right foam core or composite material? The jig is made up I’m experienced with cloth and resin.
> What are you guys using and who is a good distributor?


If you go on the Bateau.com forum you'll find all the advice you'll need, and Boatbuilder Central in Vero can supply the materials. A lot of the builders on the forum switch out different composites for decks and bulkheads, but it's more expensive than plywood and you won't save enough weight for it to be worthwhile because you need more glass and resin. A sheet of Okoume, or Meranti ply properly epoxied and glassed will last forever.


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## trekker (Sep 19, 2015)

H80 divinycell. 17 oz biax on the bottom. 1 layer of 17 oz biax and 1 layer of 7 oz. Glass on top. Will be solid as a rock and will save weight.


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## topnative2 (Feb 22, 2009)

nidacore----less expensive


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## Boneheaded (Oct 4, 2017)

Thanks guys


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## Finn Maccumhail (Apr 9, 2010)

seapro17sv said:


> If you go on the Bateau.com forum you'll find all the advice you'll need, and Boatbuilder Central in Vero can supply the materials. A lot of the builders on the forum switch out different composites for decks and bulkheads, but it's more expensive than plywood and you won't save enough weight for it to be worthwhile because you need more glass and resin. A sheet of Okoume, or Meranti ply properly epoxied and glassed will last forever.


In your experience, does using a sheet of Okume or Meranti and properly epoxying/glassing it in for your decks require less bracing underneath for a solid deck that won't flex?


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## seapro17sv (Feb 3, 2015)

Finn Maccumhail said:


> In your experience, does using a sheet of Okume or Meranti and properly epoxying/glassing it in for your decks require less bracing underneath for a solid deck that won't flex?


I'm not sure what you mean by 'less bracing', but the decks on the 3 boats I've built all have 3/8" Okoume decks with 6 oz. woven on top and the underside with a few coats of epoxy, than primed and painted with Awlgrip. I've never worked with any of the composite boards mentioned, but I assume they would also need some support frames underneath. I built my hatch gutters out of 2"x2" stock Cedar, and with the 3/8" deck thickness I use a router to create a 2" deep gutter for good drainage. The hatch frame is supported by 5/8" thick by 2" tall frames, acting like an I beam, and making for a solid deck with zero flex.


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## Finn Maccumhail (Apr 9, 2010)

Bracing, framing, meant the convey the same thing. Basically, I was wondering if the marine plywood when glassed is stiffer and stronger than composites so you could cut weight with less framing support below.


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## seapro17sv (Feb 3, 2015)

Finn Maccumhail said:


> Bracing, framing, meant the convey the same thing. Basically, I was wondering if the marine plywood when glassed is stiffer and stronger than composites so you could cut weight with less framing support below.


From everything I've read on the Bateau forum, especially from Jacques Mertens, the designer, on a small boat the weight savings is very small due to the fact that more glass and resin are required. Also with some of the composite boards you may have to be concerned with compression issues and installing hardware, like cleats etc, which would need some sort of backing to distribute the load. If you're mostly concerned with weight issues, Okoume is incredibly light, not anywhere near as heavy as conventional lumber yard ply.


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## Boneheaded (Oct 4, 2017)

Forgot ive got a family friend in the composite industry, asked him, and am going with NIDA CORE, and some fancy composite aluminum glue for my angle supports. Apparently the product has been refined over the last few years. its just for my side glades jon, with the weight savings and at 60$ a bare sheet cant go wrong. Trying to figure how to get pics up when i get it going in the next few weeks.


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## Finn Maccumhail (Apr 9, 2010)

seapro17sv said:


> From everything I've read on the Bateau forum, especially from Jacques Mertens, the designer, on a small boat the weight savings is very small due to the fact that more glass and resin are required. Also with some of the composite boards you may have to be concerned with compression issues and installing hardware, like cleats etc, which would need some sort of backing to distribute the load. If you're mostly concerned with weight issues, Okoume is incredibly light, not anywhere near as heavy as conventional lumber yard ply.


Good to know.

I was planning on going with composite core material but I'm a little nervous at the idea of trying to precisely lay out the backing areas under the deck where I'll attach the various hardware like the poling platform and so on. It sounds like I don't have to be as precise if I use marine ply due to it's holding strength, correct?


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## yobata (Jul 14, 2015)

Finn Maccumhail said:


> Good to know.
> 
> I was planning on going with composite core material but I'm a little nervous at the idea of trying to precisely lay out the backing areas under the deck where I'll attach the various hardware like the poling platform and so on. It sounds like I don't have to be as precise if I use marine ply due to it's holding strength, correct?


You should always try and thru bolt if you have the access, but as with any core material including ply, it is best to over-drill, fill with thickened epoxy, and then drill to appropriate size. This creates a collar of epoxy to ensure that the core stays dry and that the attachment point remains secure.


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## seapro17sv (Feb 3, 2015)

yobata said:


> You should always try and thru bolt if you have the access, but as with any core material including ply, it is best to over-drill, fill with thickened epoxy, and then drill to appropriate size. This creates a collar of epoxy to ensure that the core stays dry and that the attachment point remains secure.


If you use plywood for the decks and sole, it will be either 1/4" or 3/8" so you still need a backing plate of some kind, whether it be a very large metal washer, to spread the load, or some thicker wood epoxied to the underside. Don't be afraid to put some large pieces of wood in the areas that you think you will be mounting hardware, if you double or triple 3/8" ply it will be strong enough to bolt through or screw into with coarse thread wood screws. Also, don't be worried about the extra weight of some wood backing, a 4'x8' sheet of Okoume ply only weighs 20 or 30 lbs. so you might add a few lbs. to the entire build, not enough to be an issue.


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