Open cell foam in fuel tank?

Just bought a ‘75 CB400 tank off EBAY to slap onto my K8, fits great! I removed the fuel cap and the tank is full of rust and weird spongey foam. I had never seen that before and after doing research learned that it is open cell baffle foam that supposedly helps with performance and reduces sloshing.

My question is, when I pour metal rescue in there to clean out the rust, Will it affect the foam? Is it worth leaving the foam in there or should I try and clean it out somehow? I’ve never encountered this before so any advise is appreciated.

Best!

Pics would be a great help. You could test the foam reaction with Metal Rescue if you can get some of it out.

I doubt Metal Rescue would damage it, but you should test a sample first. Looks like, if it isn't attached and you are patient, it should compress enough to permit removal.

yeah, that's just racing baffle to keep the fuel from sloshing around.

I expect if fuel won't kill it, Metal Rescue won't either. I'd go for it. But it doesn't look like your tank really needs much work - why the Metal Rescue at all?

Fuel filters and off you go