How to encapsulate/waterproof/fuel-proof flotation foam?

[BWR1953]

Am planning on using the pink/blue/green rigid foam insulation available at my local big box stores for flotation for my Starcraft Kingfisher project boat. Link to my project is in my sig line.

Looking for ideas and options on how to keep the foam separated from water and fuel for the long term. Don’t want it to get water logged or melted (if a gas spill happens).

Seems like HDPE products wrapped around the foam and taped down tight just might work.
Trash bags?
Vapor barrier?
Aluminum duct tape?
Other options?

 

[Woodonglass]

No worries about water. It will never absorb water but... Gas and Oil is another story. I guess you have a below deck fuel tank and a I/O boat???

 

[BWR1953]

No worries about water. It will never absorb water but... Gas and Oil is another story. I guess you have a below deck fuel tank and a I/O boat???

Sorry, I forgot to add my boat info. It's the Starcraft Kingfisher in my sig line. Long ago I had a major gas spill while filling up a boat. It was pretty ugly. LOL

 

[Woodonglass]

Well for a "Tinner" since the deck is not sealed, there's always the possibility of Gas and Oil spills getting below deck. Wrapping the foam In Garbage Bags might help or vapor barrier. It's up to you I suppose.