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Quote Originally Posted by drdreww
so paint the top side? this system is outdoors too..
Yes...just the 'top', seems best.

Quote Originally Posted by rfeiller
what type of time frame, before it breaks down. i've never heard this before and i've never seen styrofoam break down in water, it's used in boat docks, building foundations. amazing.
It's the UV that does it. In a foundation or a boat dock it's protected from the sun.
I have a few extra rafts in a stack (stored outside), the painted tops are doing fine...I noticed the edges are showing a slight break down, after a few months.

I've been trying the expanded white styrofoam....concerned about the fire retardant in the blue stuff....the pink, I've heard, has bug poison in it too. As much stuff we are exposed to, am I being too cautious ?
I've been getting 'virgin foam' made (no fire retardant/bug poison) ...I've tried 1# , 2 # and 3# ( all 2" thick). (FL guys...it's made in Lakeland)
The 1# is too weak and it quickly gets water logged. The 2# is OK, does get 'some what' water logged. The 3# is surprisingly heavy and I think it's stronger then the blue stuff. I think I'll try 2 1/2 # on the next order.