3 pinhole leaks on the bottom of the tank. The kind that take a minute for the tiniest droplet to appear.
At least I know now. I'm taking the tank to a recommended heliarc expert who works mostly on planes.
Rodknock - I've got a few weird shots of the Autokraft in a gallery on my page. I haven't polished her all up for a decent picture yet.
In the words of Florida Evans from Good Times, "Damn, DAMN DAAAMMNN!"