Removeing the foam from around gas tank

[poengine33]

Hey guys. I started to remove the foam from around my aluminium tank in my 1979 V20 today. I see some posts that say do not refoam the tank. So I have a couple of questions.

1. Does the foam eat away at an aluminum tank?

2. In 1979 did Wellcraft foam the entire floor or just around the tank.

Thanks.