[LewisM]

Trying to restore an OLD doublet - SMALL - that was joined by Canadian Balsam (given the age of the optics). The lenses were spun and press fit into the assembly and CANNOT be removed to clean.

Should Xylene, given enough time, work it's way in through the microscopic gaps etc eventually dissolve the old balsam, leaving me an airspaced doublet? This would be MUCH preferred than the unusably cloudy optics at the moment!!!

I tried heating the balsam over an incandescent bulb, but got it too hot and it browned (previously white crystalline), so literally cooked it. I have been soaking in isopropyl alcohol and acetone, and it IS between the lenses (as I can see a bubble, that moves when I turn the lens), but it seems to be VERY slowly dissolving it. Hoping xylene might accelerate things.