Any tips to release fuel tank stuck by floatation foam

[havoc_squad]

Any tips on ways to safely pry a polymer permenant fuel tank out with the bottom likely stuck with floatation foam holding it on rather firmly.

Either that or any tips on ensuring safe cutting at the very bottom with oscallating tool without hitting the tank or gouging into the very bottom hull part.

I've gotten most of the wood stringer area around it removed with oscalling tool but wary of being too aggressive at the very bottom with the osciallating tool. z

Even though it is nearly 100% drained and no vapors present, gas vapors and electric tools don't mix so I'm being very careful.

I'll get photos later on when I get a little more time with oscalling tool to free up more area on the bow section.

 

[Scott Danforth]

A bit of air pressure helps the tank break itself loose. About 2 psi

If you can get straps around the tank, that helps

 

[airshot]

Yes, some air pressure might make the tank expand slightly to break the seal of the foam. Not sure how your acess is to the bottom of the tank, but if you can reach it, I would use a nice sharp fillet knife rather than a power tool. By hand, the tank would not be damaged by the fillet knife in my opinion.

 

[tpenfield]

I have used a variety of methods, including a strap underneath the edge as well as wedges made of 1x3 lumber pounded in underneath. It all depends on how much space you have to work with. Those were on metal fuel tanks. I am not sure poly will hold up to the forces need to break the tank loose. If all the side are free of foam, it still may take 500-1,000 lbs of upward force.

Can you post a few pictures as that may help with responses.

 

[Chris1956]

How about running a wire under the tank to "saw" between foam and tank. Be careful not to damage tank.

 

[airshot]

Sometimes that foam can be easily "melted/dissolved" with something like acetone. Test it on your tank but pretty sure acetone won't bother your tank material. Might be pretty messy but the foam can be dissolved with the right stuff.