Can I seal a small crack in an aluminum wheel with epoxy or something similar?

I have a 16 x 7 , 4 lug wheel that has a 3/4 inch crack on the inside. I am leaking about 5-7 psi a day. The type of wheel I need is nearly impossible to find. I just bought 4 new tires and don't want to just throw them out by getting a different sized rim. I was wondering if anyone knew if there was anything I could use to temporarily seal the small crack until I could find a new rim?