[myfriendis410]

I've tried just about everything, up to and including picking pine resin off of neighborhood trees. The best I've found is plain old sawdust/chips. Rouse it, let it smoke up and leave on the melt. It turns into activated charcoal and absorbs impurities while protecting the top of the melt.

Sorting wheel weights IS a pain. I never can get a magnet to work, and it only works on the steel weights; not the zinc and aluminum ones. Also, the stick-on weights need to come out too. I just eyeball the good ones after spreading 'em out on the garage floor and trash the rest.