Will this Coosa Board work?

[Capt.Joe]

I came across a good deal on 3/8” 20lb density Coosa Board and was wondering if this would be sufficient for my boat floor? My take on it was that it should be stronger and lighter than the 1/2” marine plywood. Any feedback would be appreciated.

[mshugg]

What boat?  What are your distances between supports?  3/8” is a bit thin for a floor.  Coosa recommends that you use the same lamination thicknesses as in the original boat.  I believe most AquaSport’s used half inch cores in floor. 

You can probably get away with 3/8”, but you will probably need to use mare glass in the skins most likely offsetting any cost savings.  Keep in mind that with any cored construction, the thickness of the core is important for stiffness and strength.

[Capt.Joe]

What boat?  What are your distances between supports?  3/8” is a bit thin for a floor.  Coosa recommends that you use the same lamination thicknesses as in the original boat.  I believe most AquaSport’s used half inch cores in floor. 

You can probably get away with 3/8”, but you will probably need to use mare glass in the skins most likely offsetting any cost savings.  Keep in mind that with any cored construction, the thickness of the core is important for stiffness and strength.

It’s for a 74’ 22-2. I haven’t started on my bulkheads yet and won’t know exact distances between supports. Buying it at this price should save me about $500-$700 dollars, but you get what you pay for.

I figured it would be better than marine plywood but not as durable as the Bluewater Coosa. It is the Nautical series coosa board.

[mshugg]

The 20 pound density isn’t the problem.  At 20 pounds it’s four times denser than h80 divinycell that is commonly used for decks.  It’s the thickness that will limit you.  Now if you could double it up, so your thickness is 3/4” it would make an awesome deck core.  Of course the bond between layers is critical.

[Capt.Joe]

Thank you for the feedback mshugg! In reality I know a 1/2” deck would let me sleep in peace, but my wallet keeps saying, “It’s only a .125” difference”.

[BradC]

Thank you for the feedback mshugg! In reality I know a 1/2” deck would let me sleep in peace, but my wallet keeps saying, “It’s only a .125” difference”.

Yip ... but it equates to a 33% difference

[Tampa Bay Mike]

I used the 20lb coosa in 1/2". I did one layer of 1708 on the bottom and two on top and it's plenty stiff with the bulkheads I used. I think you could get away with it but I would add at least one more layer of glass. My question would be is the cost savings enough to offset the extra glass and resin and still be a good deal? If so, I'd do it.

[Capt.Joe]

I used the 20lb coosa in 1/2". I did one layer of 1708 on the bottom and two on top and it's plenty stiff with the bulkheads I used. I think you could get away with it but I would add at least one more layer of glass. My question would be is the cost savings enough to offset the extra glass and resin and still be a good deal? If so, I'd do it.

Thank you, Mike. I think the savings would be enough to offset the extra glass. How many 4’x8’ pieces did you need to use for your floor?

[Tampa Bay Mike]

I used the 20lb coosa in 1/2". I did one layer of 1708 on the bottom and two on top and it's plenty stiff with the bulkheads I used. I think you could get away with it but I would add at least one more layer of glass. My question would be is the cost savings enough to offset the extra glass and resin and still be a good deal? If so, I'd do it.

Thank you, Mike. I think the savings would be enough to offset the extra glass. How many 4’x8’ pieces did you need to use for your floor?

I used five total. Three for the sole and two on the casting deck and had enough left to make the bulkheads.