I'm looking for something to seal and convert rust on the interior floor pan. POR-15 was the standard once, but many failures have been documented so I'm looking for better alternatives and don't want to read countless web site pitches. The rust will be wire brushed and any porosity in the steel will be cut out and patches welded in. But I'll need something to coat the treated steel any freshly welded patches. I only want to do this once and cover it with sound insulation. Any suggestions? Thanks!