Spray foam floatation?

[Suprathepeg]

Redoing the floor of my 1988 maxum 1700. I am considering using a 2lb poly iso close cell foam instead of standard floatation foam. The advantage being that it will never hold water and help stiffen the hull. Any thoughts?

 

[bonz_d]

Spray foam? Is this a 2 part foam? How is it different from standard foam?

 

[batman99]

Good reading at: http://www.rhhfoamsystems.com/marine.php and https://www.generalplastics.com/marine.html

Since my 17ft boat is either stored on sloped trailer or sloped boat lift with its rear plug removed, I'd give Marine Grade Closed Cell Spray Foam a try. In my simple world, it sounds like it should work good. Especially if rear plug is removed and any water entry is allowed to drain away - out its rear plug.

Note: I hear some closed cell formulas are now available with fire resistance additive (formula). For a boat with gasoline, wiring and battery, I'd probably use this fire resistance version. Especially if it didn't have a huge cost variance.

Hope this helps

 

[Yacht Dr.]

Welcome to Iboats Supra..

I guess whichever one you want to use. Both polyurethane and polyiso is closed cell..at about 95%. But dont think your getting a pure waterproof pour. You still have to contend with water entrapment..delamination etc. I could be wrong..but I still think water could get into the foam if left over time.

And..if your talking spraying..then it might be hard to jam the tip of the nozzle down them little pour holes :laugh:

As we say .. Whatever floats your boat.

 

[Suprathepeg]

Compared to what was in my boat this stuff is much less vapour permeable. We use it to insulate the outside of basements in wet environments. It's also really hard once installed. Future removal would be a huge ***** for sure.

 

[Woodonglass]

Suprathepeg, the spray in foam you're referencing is not 100% water proof just as the 2lb density foam commonly used in boats is not. Both foams, if left totally immersed in water for extended periods of time will eventually absorb water. It does take a long time for this to occur and unless extreme lack of care and maintenance is done to your boat you shouldn't have to worry about using either one of them. Are you planning on spraying the foam in prior to laying the deck?

 

[Suprathepeg]

I was thinking of using holes to spray into te cavity. It may be a bad idea though this stuff has some crazy force if you over do it.

 

[alldodge]

I was thinking of using holes to spray into te cavity. It may be a bad idea though this stuff has some crazy force if you over do it.

Agree with WOG, it appears your talking about open cell foam found in the spray cans, this stuff is no good. You needs at least 4lb closed cell foam. All of the foam exerts some pressure

 

[alvear747]

I am considering doing the very same to my project I recently purchased. I just bought a stinger bass boat, and i am trying to decide which product. I am looking at aeromarine products, the 2 part mix formula

 

[ondarvr]

I can't tell you the exact differences between the typical Coast Guard approved foam and what you plan to use, but......

The CG foam needs to be gas, oil and diesel resistant, not sure if yours is or not. Other than that there is probably little difference in performance.

You don't want to use spray foam in a pour foam application, it expands far too quickly, you can spray it in place prior to laying the floor down though.

 

[Suprathepeg]

Yea I'm just gonna use pour in foam. Less stressful lol.