expanding foam

[larryrose11]

All,
I have a cheetah, and I want to fill the fron section with polyurethane expanding foam.
This is the pourable AB, closed cell foam.
The function is to provide flotation, but add rigidity so WHEN a crash happens, there is a big pocket of air in the front. in a flip, the front deck will get compressed, blowing seals and such.

My question is:
What density of AB foam do I want? is 2# density enough? do I want 4# density?
I have the 2# density spray foam in my house walls, (holey hell does that stuff work!!) and Im questioning what density I should use.
any experience out there?

Thanks

[Fluid]

The SEARCH function is your friend, this has been beaten to death.

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

[larryrose11]

Thanks Fluid. The search didn't function at my workplace.

[tlandauer]

The SEARCH function is your friend, this has been beaten to death.

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

http://forums.offshoreelectrics.com/...highlight=foam

Man, I BS'ed in every one of those threads!

[kfxguy]

In my cheetah I used sheets of the pink foam you get at home depot. Its two layers thick. Its siliconed in.

[rickwess]

The 4lb foam is more structural and sands easier than the 2lb foam, but puts more pressure on the hull when expanding. The 2lb foam is better for flotation as there is more trapped air in the foam.

If you have the 2lb foam already, you can "simulate" 4lb foam by pouring it when it's cooler, say in the 60's F By it, I mean the 2 part foam, not necessarily the ambient temperature. It will expand less and be more dense. You're in Mi so that shouldn't be a problem right now.

Do small pours (~25g total) and keep a little inward pressure on the hull with your hands where the foam is currently expanding. The small pours will also allow you to ensure the entire cavity gets filled. Sometimes the foam will expand in a way that it leaves a small gap close to the hull. Simply direct a little of the next pour into those gaps.