Is it necessary to use Tank Sealer

[Can_CB1]

Hi, I am cleaning out the fuel tank as part of winter service as it had some rust and flaked off paint in it. Once I get it all clean and void of rust is it a good idea to seal with por-15? I noticed there’s two pipes inside the tank I’m assuming for overflow and venting. Is there any issues with these getting coated in the sealer?

When I emptied the gas about a cup pooled in the tank and I couldn’t remove without using rags. Is there a tip to get everything out? I wouldn’t want the sealer to pool in there and using rags before it cures would just wipe away parts of it