Muggins
Junk magnet
Does anyone have a rear element/group* for an uncoated 1930s front-focusing model in their spares box that I could beg/buy/borrow, please?
I've just been given a Kodak Six-20 Model C with a Compur shutter and said Xenar, with quite an interesting history, that I'd like to use if possible, but the rear element has a nasty spall on it where it has obviously been hit at some time, and some dodgy looking scratches. Conversely, the front element is clean as a whistle - make sense of that!
If anyone has a lens or part lens that I could have I'd be very grateful.
Thanks!
Adrian
*I've not found a diagram of the Xenar, so I'm not sure whether the rear glass is a single element or a group as in the Tessar.
I've just been given a Kodak Six-20 Model C with a Compur shutter and said Xenar, with quite an interesting history, that I'd like to use if possible, but the rear element has a nasty spall on it where it has obviously been hit at some time, and some dodgy looking scratches. Conversely, the front element is clean as a whistle - make sense of that!
If anyone has a lens or part lens that I could have I'd be very grateful.
Thanks!
Adrian
*I've not found a diagram of the Xenar, so I'm not sure whether the rear glass is a single element or a group as in the Tessar.
Dan Daniel
Well-known
Muggins
Junk magnet
Thanks, you must have more patience with the S-K website than I had!
Adrian
Adrian
Murray Kelly
Well-known
I've got an idea. Don't disassemble the lens. It's possible that a solution of Canada Balsam in xylene will cure the cracks.
Do you have access to xylene (try the local giant hardware store)? If so I can send you a quarter inch lump of balsam and with care a drop of the solution will fill all the tiny gaps.
After all the compound lenses are usually combined with balsam.
Muggins
Junk magnet
I work in the sort of lab that might well have xylene - I'll have a word with the histology types on the QT and see what I can come up with. If I can get a little (it's distinctly frowned upon to have it around these days), I'll let you know. That's a very kind offer, Murray!
Adrian
Adrian
Murray Kelly
Well-known
In that case they may have the balsam, too. Used to be used to make a circular cell before mounting a specimen. Ask. They'd be just the right people.
Let me know if you need it, but.
The solution will wick into the cracks and I'll bet you won't be able to see them.
Muggins
Junk magnet
Finally found someone in the right lab to talk to, they certainly have xylene... somewhere! I'll give you a yell if I need balsam as well...
Adrian
Adrian
Murray Kelly
Well-known
OK - we will wait and see.
citizen99
Well-known
FWIW some paint stripper types contain xylene, if I remember correctly. I don't have one to hand to check the label for content percentages, but the one I had was quite clear.
Murray Kelly
Well-known
Also lacquer thinners. It's slower to dry. And goopier. I originally used that and a small blob on a window was there for some years. May still be for all I know.
I remember Locktite have a glass glue. It's a kind of acrylic glue I used once to glue a broken vase with. It cures by UV light, meaning you let it sit in the sun. I cannot recall if it would be thin enough in consistency to 'wick' into a glass crack.
IIRC Leitz used something like that for a short period. The lenses were permanently stuck together they found out later and couldn't be separated for correction of micro cracks etc. That experiment didn't last long. They went back to the balsam glue.
Murray Kelly
Well-known
What's happening? Any news? A new, perhaps?