Final call for lens doublet separation.
I might have entitled this something more specific or eye-catching, but the title line cuts off on long titles. Specifically, I have in my charge the now-ewtracted front doublet from an older-style silver Hasselblad Zeiss Planar 80mm. It belongs to a good buddy, and he has faith in me to get them apart with their coatings intact and use this little bottle of Balsam Fir gum to get them back together again. He refuses to accept that the 3/32 ring of separation around the perimeter is of no concern.
I've studied hot water, a crazy light-bulb trick, and acetone. These are my final choices, excluding the crazy light-bulb trick. Because I know that the indisputable experts at the big lens re-coating company that shows up high on the google listings say: "be prepared to accept that temperatures above 200 degrees may damage lens" The glass itself can't accept that, not even considering the coating too.
So that brings us to dropping the doublet into a padded jar of acetone for about a week. I'd REALLY like to know how lenscoating likes that. Because I can't think of any other coating, including porcelain and powder-coating that can stand a long soak in acetone.
I intend to do the separation in the next few days. Last call for a bright idea. Thanks.