Do brand new gas tanks need to be sealed?

I recently purchased a brand new gas tank for my thunderbird and have prepped and painted the outside. Before I install it do I need to seal the inside with something like POR-15 or should it be good as is?

Thanks!

 

No no no! Edit, to be clear, don't seal it.

 

I thought the sealant was only for restoring an old tank, just wanted to check. Thanks!

 

Yep, it's a last resort kind of deal and quite often doesn't work out well.

 

For many years OEM type tanks were protected by a solder-like layer called Terne coating. Due to environmental concerns tanks are now plated with zinc or other metals. If you wanted to seal the tank, proper adhesion of the sealer would require acid etching or completely removal of the existing plating. Sealers sometimes fail, so it wouldn't make sense to compromise the factory coating to apply a sealer. Methanol attacks the platings used on gas tanks. So no matter what coating/plating the tank has, be sure to avoid fuels and fuel additives(like cleaners and dry gas) containing methanol. A little Isopropyl alcohol won't hurt anything, so be sure any alcohol containing products are isopropyl or ethanol and not Methanol.

 

My buddy sealed his brand new tank in a '32 3 window. One day, the car wouldn't run. The sealer was flaking off and clogging the everything.

 

Painting the outside is a no-no from what I was taught, but I forget why.