I have performed complete re-seals on all of my past campers on both types of siding: meal and Filon.
These sidings are pretty durable, but I found more potential for scratching the finish on the metal siding so it need more care in removing old caulk. The Filon is quite durable and I had no issue using a regular putty knife and other steel scraping tools. In some areas I will even use Brak-Kleen as a solvent.
I have resealed metal and membrane roofs. These require MUCH more care in removal of old as those coverings are more delicate. Often plastic putty knives were used as well as metal with a lot more “easiness” of scraping.
As far as applying new sealant when all prep was performed, I would use acetone as a de-greaser. Formerly I used Geo-Cel on the walls. But on my last camper I used a different sealant:
OSI Quad-Max. I would still use Dicor self-leveling on the roofs because the OSI does not self level.
I did not use any profiling tools… moist finger was sufficient to smooth it out. When applying, be sure to not apply too much. If the bead was too big, it would really booger the appearance when smoothing. Use painter's tape in areas where a more critical line is desired.
Also- throw way that old cheesy stamped-steel caulk gun and get a decent quality one. The new ones with better materials are the same principle as the old but with much better results. The rotating barrel makes it much easier in tricky places:
Improved Caulk Gun.(edited for clarification.)
