Jsmall01, read " sealants summary thread " https://www.airforums.com/forums/f45...116214-14.html
and references to Tolley's. I understand is best for rivets and seams as it not topical but is absorbed (wrong word)...drawn into seams etc.
Chasing a leak is crap shoot without a verified target. 221 is the best but is best for penetrations and roof vs vertical seams. Leaks remind me of the Nicholson line in Chinatown. Loosely quoted...forget it jake, it' Chinatown...meaning it's not what it seems. My leak by the closet actually came from a near by....sorta... via rib to the wall from a crack in the fantastic vent base flange. I never saw a drop, but felt the soft spot and started to poke around. I was lucky,noticed a very small crack on the corner. 221'd it, pulled the inside flange of the FV, saw the evidence and knew i had found the leak. BTW, FV replaced the entire unit under 7 year warranty. Crack likely over torquing at mfr.
I was lucky as i found the exterior indicator and that pointed to the interior spot. Screw penetration for solar...could be dripping along a rib from anywhere.
IMO, i would call bay area Airstreams,Cordelia @ I80 in Solano county. I have heard the have pressure testing capabilities for leak locating.
P.s...curved seams can and do leak.