resilvering a mirror, making gg

[jnanian]

aside from buying a parts camera and
harvesting original parts from it ...
what is the best way to resilver the mirror in an old rolleicord TLR ?

i also want to make my own ground glass
to replace what i have in there ...

maybe for both the mirror and gg i have to measure what i have and match it ?

any shortcuts are greatly appreciated !

thanks!
john

[holmburgers]

I don't know much about this, but in Wall & Jordan's Photographic Facts & Formulas there are a multitude of recipes to silver glass. It sounds quite difficult and finicky, but intriguing nonetheless.

You can also by first-surface mirrors for reasonable prices and you could cut them to size.

[Bob-D659]

You could send it to one of the places that silvers telescope mirrors.

[Ian Grant]

There's a supplier of new mirrors for Rollei's on ebay and I bought a very reasonably priced new focus screen for a Rollei off ebay 2 or 3 years ago, it's better than a plain screen as it has a focus spot bit in the centre. I had wanted to use it on my Yashicamat but it's not feasible. It was a lot less than those currently listed about $30, I think you can cut a Mamiya 67 screen to fit as well.

I do prefer yo make what I can for myself but these are two items that aren't expensive.

Ian

[Roger Thoms]

http://www.apug.org/forums/forum147/...r-mirrors.html

John, check this out, might be worth a try.

Roger

[ntenny]

Stained-glass supply stores will have first-surface mirrors, along with the tools to cut glass cleanly. I would think you'd need to measure what you have and match it.

I don't know what controls the mirror position in a Rolleicord. Are there rails that it sits on, or something? If so, the thickness of the mirror would be critical, since it would affect the length of the light path.

As far as the ground glass, I've done it and it worked fine, but my grinding compound was too coarse. The results were usable but not very attractive. It's not hard to do, but unless you have a specific desire to do it yourself, the eBay replacement screens seem like a win to me. I've got one on my Rolleiflex---I can't remember which seller, but one of the usual suspects---and it's fine, I'd say comparable to the OEM screen.

-NT

[holmburgers]

There are also ways to acid etch ground glass. Does anyone know if the results are better or worse?

This company sells all kinds of glass, including front-surface mirrors & opal glass... http://www.howardglass.com/home.htm

[Sethasaurus]

jnanian,

You can get mirrors re-coated here.
I just checked their link and they may have website trouble at the moment..
Here's their contact info:
Vacuum Coatings Ltd (Scientific Mirrors)
66 Barrett Road
Walthamstow
London E17 9ET
Telephone / Fax 020 8520 5353
enquiries@scientificmirrors.co.uk

There are places in the US that I looked up a while back but I used the English guys as they were closer to me.

I actually got a mirror for my Pilot 6 recoated by these guys. They did a good job, albeit a bit slow, and it came to around 12 pounds, I think.
Unfortunately, I broke it in half while reinstalling it! My first ever glass breakage. Oops.

The mirrors from compact cases are very good. Some of them have paint on the back that will not come off with acetone or paint-stripper - Chanel is one brand to avoid for this job.
I spent a lot of time trying to cut the ~1mm glass but didnt do too well. I think the best thing to cut thin glass is a Dremel with a cutting wheel (which I don't have).

In the end, I ordered 'dolls house' mirror from a seller on ebay. It's 1mm thick plastic with a mirror surface and it works perfectly (also, you can cut it with a knife or scissors!)

Ground glass is easy if you can get the thickness of glass that you want - small picture frames often have quite thin glass ~1mm also.
Get some valve-grinding compound from an engineering supplier or walk down the road to your nearest motorbike mechanic and see if he'll give you a blob of it
If you do a google search, you'll find a description of the process (fairly easy).
I have also used wet&dry sandpaper after the grinding paste, to get a finer grain on the glass. I use it to sand cracks or chips off vintage glassware, starting with about 400 grade, and 1200 will almost give you an unnoticeable finish.

One other thing - I bought some A4 fresnel lenses for a few bucks each and cut the center out to place under the ground glass in my Pilot 6 (which is known for it's dim finder at f6.3) and it brightened up quite a bit.

There's always a trade-off with DIY vs BIY

[John Koehrer]

Homemade GG is pretty easy and i may have some compound left over. Want it and it's yours. I used a Dremel with cutting disc for the corners and surprised how easy it was.
I also had one that was a fraction of an inch to large on one dimension and used 400 grit wet and dry sandpaper to sand it down. 10-15 minutes and a bunch of trial fits.

[waynecrider]

I have a friend that is a retired glass artist. Apparently they know how to silver glass as he told me the process quickly, and which I immediately forgot. Maybe check a forum if there is one on the subject.