View Full Version : Dismantle spun-in lens cells?

John Marriage
3-Feb-2012, 10:02
Has anyone succeeded in extracting the glass from a lens cell which is secured by a thin metal lip being spun over the edge of the glass? I have a ~100-year-old wide angle rectilinear by C Burr, generally good but with badly separated and yellowed cement holding the rear cell together. I can easily unscrew the whole thing - a brass ring unscrews from the barrel. But to get the glass out, to re-cement it, requires the curled-over metal to be curled back. Or cut off, but then what? It would be all too easy to make things much worse here! Any past experiences, good / bad, welcomed.

John Koehrer
3-Feb-2012, 16:02
The lip can be carefully unfolded, but will be somewhat marked when you reassemble, I use a very small dental probe with a flat edge. The edge is on the order or an X-acto blade. You need to work around the perimeter several times, very gently.
The edge can be folded back with a plastic tool or knife of some sort

4-Feb-2012, 08:39
I'd cut it like a can opener and make a new threaded front mount for the barrel...cut from outside with nice precision tool and you don't mess up the glass...of course i've never done it, but that's what I'd do

Jason Greenberg Motamedi
4-Feb-2012, 10:01
I have opened them at home using small tools, as John Koehrer describes. The result is functional, but looks crappy when folded back. With more valuable lenses I have sent them to John at Focal Point to do the work and re-cementing. I am sure that the Grimes boys could do it too.

4-Feb-2012, 12:47
The ONLY safe way is to use a lathe and a 4 jaw chuck to cut it off. I turn the chuck by hand. never use the motor. thats called a burnished mount