I have a ‘76 Shasta with an aluminum roof that needed new sealant along the roof seams. I applied (probably too liberally) a good amount of proflex along the seams. A couple of days later I looked to see some brownish-orange discoloration in certain areas of the proflex. Is this some sort of rust? The plan was to paint over everything with Rustoleum oil based white, but I want to make sure the seams are good to go first. Any idea what this might be? Thanks
Proflex should always be painted so that is correct. The orange discoloration is caused by contaminants from previous sealants.
The seams should be cleaned of old sealant before applying Proflex. It may or may not work if over old sealants. Also, it's rarely the seams that leak. The edge trim (J rail, awning rail, etc) should have new putty. The wood underneath should be sound so the screws grab well and ooze the putty.