Question about floatation Foam

[Mat2894]

I am currently replacing the deck on my 94 bayliner capri 1750 and have all the wood back in place and it is all glassed in. Could i put the boat in the water to test my outdrive and motor without the floatation foam shot in yet or would that be unsafe. I am not sure if the boyancy would be thrown off or if it will float at all. Also what type of foam should i get? I know i have to use a 2 part but there are so many out there and i am not sure what is worth a damn and so fourth.

any help would be great


Thank you,
Matthew

 

[RWilson2526]

Re: Question about floatation Foam

Displacement is what makes your boat float, not foam....foam is a safety feature so that if you get swamped your boat hopefully wont go right to the bottom before you have time to bail.

not sure about what foam to use but I would be cautious with the spray stuff....if you put in too much you are going to push you floor up

 

[Mat2894]

Re: Question about floatation Foam

So there is no structural intergrity lost without it?

 

[RWilson2526]

Re: Question about floatation Foam

in your boat, no it is just for flotation. Here is an interesting article about foam.http://www.glen-l.com/weblettr/webletters-7/wl55-flotation.html

 

[tboltmike]

Re: Question about floatation Foam

The foam sold in aerosol cans that you get in the dept stores are one component systems and are air cured. If it is cast in volumes over 1 inch thick, curing to the core is doubtful. The outside skins over and seals the inside. Also, these are very low density. Good for floatation, but crush easily. Therefore, this is not a wise choice for floatation and may say so on the can.

There are USCG approved foams. These are two component systems and have a density upwards of 2 lbs/cuft, maybe 4. The two part systems can cure when cast to any thickness. They are available in paint type cans or pressure bottles with hose end static mixers.

If too much is poured in a confined space, the vessel can be ruptured and much heat is liberated. These reactions take place quickly and this stuff doesn't come off your skin easily or exposed structures.

Good Luck, Mike

 

[tinkeringwackyone]

Re: Question about floatation Foam

Look for closed cell foam as it does not absorb water easily. Its a two part mix, just be careful not to pour to much in at time due to heat build up.

 

[BobsGlasstream]

Re: Question about floatation Foam

Hello folks,
I really do love this forum. There is just so much great information on here. I am not being sarcastic,I really mean it.
As for the foam, the exotherm on most foam systems will be between 180 to 230 degrees F in it's core. If you get it on you it is very difficult to remove. Did I say it's hard to remove, well it is. Most urethane foams cannot be remove with chemicals either. So just avoid getting it on you or you will be picking at it for awhile, Trust me on this I know. It really won't burn you if it get's on you much. Maybe a red spot but not much. Also like said in previous post make small pours and what ever you do don't try to plug the hole you are trying to pour it into to keep it from coming out. It will come out somewhere if overpacked, I have seen it blow molds open. Just wait till it cures and cut the extra off. When mixing just be ready to pour before you start mixing you won't have much time to mix and pour. Most systems less the a minute. Most foams available to cunsumers will be 2-8 lbs per square foot, that is in a free raise state. It is also not the cheapest thing either.
It is not as bad as it may sound either. The polyol is water soluble and you can wash it off with water. The Iso will react with water (The Amber looking stuff). Once mixed and cured they are very stable and safe.
1. Just wear proper PPE
2. Small batches.
3. Use a drill mixer. You may even want to have someone with a timer to get max mixing time.
4. Be pepared to pour before mixing.
5. Don't try to plug the hole while foam is rising.

Hope this helps, and have fun.
Didn't mean to be so long winded either.