Rangefinder film handling - tips?

[Murray Kelly]

With a couple of cameras needing attention to the mirror in the eyepiece (not the moving mirror) I managed to get some film to attempt a repair. My question is: How do you handle these tiny pieces of film without ruining the stuff?
One I have measured has a rectangle 5x8mm and the thought of handling it gives me pause to start the job.
I have thought of a piece of bluetack on a toothpick and apart from tweezers, nothing else comes to mind.
Maybe I should put on a bigger piece and try to trim it down with a scalpel.
Anyone with experience offer some help, please?

Murray

 

[Murray Kelly]

I have some 35% film (passes 35%) used in commercial window reflective glass. The camera I have has a piece of glass which corresponds to the 'd' in the diagram. No prism.
At present it appears as if someone has tried to clean this patch and suceeded only in removing two stripes off it and the result is it can't be used at all. The original reflective patch is gold coloured but I couldn't get that so have to make do with plain silver.
The glass is about as thick as a microscope slide and with a loupe I cannot see any sign of a joint between two separate sheets of glass. Under a light I can just see the reflection of the patch on the back surface when looked at one way but not the other, which leads me to believe it was scintered on somehow on one surface.
My film is supplied on a thicker support sheet which one peels it off from before application. I have to get the rest of the patch off but before I go that way I would like to think I can replace the patch, even tho the r/f is useless as is.
Murray

 

[FallisPhoto]

I have some 35% film (passes 35%) used in commercial window reflective glass. The camera I have has a piece of glass which corresponds to the 'd' in the diagram. No prism.
At present it appears as if someone has tried to clean this patch and suceeded only in removing two stripes off it and the result is it can't be used at all. The original reflective patch is gold coloured but I couldn't get that so have to make do with plain silver.
The glass is about as thick as a microscope slide and with a loupe I cannot see any sign of a joint between two separate sheets of glass. Under a light I can just see the reflection of the patch on the back surface when looked at one way but not the other, which leads me to believe it was scintered on somehow on one surface.
My film is supplied on a thicker support sheet which one peels it off from before application. I have to get the rest of the patch off but before I go that way I would like to think I can replace the patch, even tho the r/f is useless as is.
Murray

If I am understanding you, you'll probably want to clean off the rest of the gold stuff, and then, well, you were right on track with your tweezers idea (I'd use polished shovel-tipped stamp tongs, designed to handle old and delicate stamps without damage). If possible, I'd remove the glass first, cut the film oversized and trim down the edges with a really sharp X-acto knife. This isn't always possible though.

Stamp tongs: http://www.linns.com/howto/choosingtongs/choosingtongs.asp?uID=

 

[Murray Kelly]

Fallis - the glass is indeed out. All the elements in the viewfinder seem to have been stuck in with something like shellac which has become 'tired' over the last 50 years. As a consequence I have to put them all back in with something similar. Luckilly I noted where they all go before I fiddled.
Since the glass has the old gold on one side I thought to experiment with a patch on the other side first and if it shows enough promise, then remove the old patch somehow.
Can't be hard - someone with something has already started it, seemingly.
Trimming a larger piece with a scalpel will be my first attempt as you suggest.
Those tongs look remarkably like the tweezers my good lady wife uses to pluck eyebrows! 🙂

Thanks for the input.
Murray

 

[FallisPhoto]

Fallis - the glass is indeed out. All the elements in the viewfinder seem to have been stuck in with something like shellac which has become 'tired' over the last 50 years. As a consequence I have to put them all back in with something similar. Luckilly I noted where they all go before I fiddled.
Since the glass has the old gold on one side I thought to experiment with a patch on the other side first and if it shows enough promise, then remove the old patch somehow.
Can't be hard - someone with something has already started it, seemingly.
Trimming a larger piece with a scalpel will be my first attempt as you suggest.
Those tongs look remarkably like the tweezers my good lady wife uses to pluck eyebrows! 🙂

Thanks for the input.
Murray

Shellac is probably exactly what that is. You are probably right about using more shellac to glue it all back into place too -- the obvious substitutes, contact cement, Duco and epoxy, are not exactly meant to be removable.

Removing the old patch indeed should not be difficult. Usually the semisilvering is deposited aluminum vapor and it just rubs off. A lot of people have found out the hard way that it usually sticks to fingers better than it does to the glass.

Your wife uses stamp tongs to tweeze her eyebrows? Mine came with a set of 4 hobbiest's tweezers. I think it was a good investment. The needle-pointed ones are great for handling small screws, I have a pair with angled tips (also good for handling small parts, in tighter spaces), and the stamp tongs..., well..., you already know about those. There is also a pair of self-gripping tweezers.

 

[Murray Kelly]

Haven't had a chance to get at the camera in question. But I agree that getting a wife that came with a set of tweezers was a very good investment ! 🙂

The shellac I have, so that was what made me look at it hard enough to decide that it just could be what they originally used. I have heard it was used for the leather trim glue, but not the setting of lenses.

More to follow.
Murray

Shellac is probably exactly what that is. You are probably right about using more shellac to glue it all back into place too -- the obvious substitutes, contact cement, Duco and epoxy, are not exactly meant to be removable.
Your wife uses stamp tongs to tweeze her eyebrows? Mine came with a set of 4 hobbiest's tweezers. I think it was a good investment. The needle-pointed ones are great for handling small screws, I have a pair with angled tips (also good for handling small parts, in tighter spaces), and the stamp tongs..., well..., you already know about those. There is also a pair of self-gripping tweezers.

 

[FallisPhoto]

Haven't had a chance to get at the camera in question. But I agree that getting a wife that came with a set of tweezers was a very good investment ! 🙂

The shellac I have, so that was what made me look at it hard enough to decide that it just could be what they originally used. I have heard it was used for the leather trim glue, but not the setting of lenses.

More to follow.
Murray

My stamp tongs came with (in) a set of four hobbiest's tweezers. My (ex) wife came with pink curtains and was not a particularly good investment.