Try Surplus Shed. They sell a 1/4 lb. chunk (enough for the rest of your life!) for $25: http://www.surplusshed.com/pages/item/b1077.html There is a rather generalized description of working with balsam in ATM book 3 (Amateur Telescope Making, by Albert G. Ingalls, et al), beginning on page 69. I know I've read a more detailed description somewhere but at the moment the source escapes me. There are also modern cements, some utilizing a U.V. cure that are much easier to handle than balsam. I have cemented small lenses using plastic cement decades ago, and I can't recall the brand, sorry! On 5/31/07, Tom Davies <oremguy@qwest.net> wrote:

I just recently bought an old telescope and the 25mm eyepiece has crackling that obscures most of the field, apparently caused by dried cement. I took the lenses out of the eyepiece housing and can remove the old cement with a solvent but am at a loss on to how to proceed further (i.e., obtaining Canada balsam, melting it, and recementing the lenses). Has anyone done this and able to give me some advice?