Club 80-90 Forums

Hi guys n gals doing some prep work before my van gets
Rollered.now I'm dealing with some rust on the seames justnow.I know they have some kind of filler in them.
Does anyone know what the stuff is called or is there an alternative I can use or is it even required ?I am not taking panels off of van.

A pu sealant will do it, some use sikaflex others tigerseal