It's possible- - - -never tried that approach. We used to build up our own rims for dirt trackers and tractor pull trucks by cutting one flange off in a brake lathe, welding in an extension, and rewelding the flange. Of course, those wheeels only needed to hold air for a few hours, not months at a time. We epoxied the weld beads to seal up any pinholes and kept a close eye on the pressures- - - -usually in the 10-20 PSI range.
Jerry