Re-mirror advice sought

[dbailey56]

I’m having the time of my life restoring a circa 1936 medium format SLR the Werkstatten Pilot 6. Earlier this year “tunalegs” posted a great overview here in the forum of his Pilot 6.

Mine showed no image at all in the ground glass and when I dismantled things far enough I realized why. The mirror sort of forgot how to be a mirror. Happy to say I got the mirror out without damaging it. Had to hold my tongue just right to do that one! Slid it into a bowl of my favorite grime cleaner – Simple Green. Before it hit the bottom of the bowl the mirror and every speck of junk on that glass was gone.

I was so amazed I almost laughed out loud. I now have a perfectly clear, perfectly clean piece of glass. It was amazing how fast it took all that off. Not exactly what I had in mind but I can work with it.

They make a “spray on mirror” product that reviewers think is pretty good, although I doubt any of them have used it to re-mirror a camera. But I ordered a can of it last night and will give it a try. It's interesting that to make it even more reflective you overcoat the mirror product with two coats of flat black paint. Kind of makes sense I guess because when you look at the back of a mirror you don't see mirror.

Here is where your collective brilliant mind comes into play. Advice please? The mirror seems to be made from the same glass as the ground glass – smooth on one side and matte or textured on the other. This re-mirror product is sprayed on the back of the glass. So which side should receive the mirror paint – smooth or matte?

I have a theory but won’t pollute your clear mind with it until I hear your ideas. And please forgive the crude drawing but it helped me think.

Thanks for any feedback and ideas!

 

[Dwig]

The smooth side of the glass should receive the silvering AND that side needs to be the top side of the glass and not the back. The image needs to reflect off of the top side.

 

[dbailey56]

That does make sense Dwig, but won’t work with the product available. Hummm.. this is going to be more challenging than I thought since all mirrors I know are reflective on the back of the glass.


I assume I would be throwing the focus off if it came from the back of the glass, using the matte to hold the texture and the smooth side on top?

 

[Dwig]

... this is going to be more challenging than I thought since all mirrors I know are reflective on the back of the glass...

All reflex mirrors used in all SLRs and TLRs are "front surface mirrors", silvering on the top surface of the glass. The only exceptions I've encountered are a few ancient large format SLRs which used rear surface mirrors. For many, many years this silvering (whether silver or aluminum) was left unprotected and was exceptionally easy to scratch and became oxidized in a moderate period of time. Most "modern" reflex mirrors (since the late '70s or early '80s) are overcoated using a process similar to lens coatings.

 

[Jerevan]

If the "spray and pray" solution goes pear-shaped, maybe this seller (no connection, etc) could help out with making a new mirror:
http://www.ebay.com/sch/marty1107/m.html?_nkw=&_armrs=1&_ipg=&_from=

As far as I've understood it, you could contact him and ask for a price on a new mirror - you still have the exact measurements available since you have the glass that once was a mirror.

🙂

 

[Dan Daniel]

If the "spray and pray" solution goes pear-shaped, maybe this seller (no connection, etc) could help out with making a new mirror:
http://www.ebay.com/sch/marty1107/m.html?_nkw=&_armrs=1&_ipg=&_from=

As far as I've understood it, you could contact him and ask for a price on a new mirror - you still have the exact measurements available since you have the glass that once was a mirror.

🙂

Yep- send marty a couple of photos and the dimensions of the existing mirror, and he'll make you a new one.

The reason your old glass was able to be ground on one side and smooth on the other is that the silver was applied to the smooth surface and the ground surface was behind it and never used. Your present glass will not work as a second surface mirror- the ground surface will dfiffuse either the silvered/sprayed area or will diffuse the de=second surface reflection coming and going.

 

[dbailey56]

all excellent ideas.. thanks a ton. Looks like I better get in touch with Marty!

Maybe I can use that "spray and pray" for a decorative vase, lol.

 

[dbailey56]

Jerevan and Dan – you are magic! I contacted Marty on the auction site as you suggested. Sent him the dimensions yesterday and he’s already put my new perfectly cut front surface reflective mirror in the mail coming back to me today. Woot!

 

[Dan Daniel]

Jerevan and Dan – you are magic! I contacted Marty on the auction site as you suggested. Sent him the dimensions yesterday and he’s already put my new perfectly cut front surface reflective mirror in the mail coming back to me today. Woot!

Great! When it arrives, you'll notice that one side looks pretty darn mirror-ish while the other side has a blue film on it. The blue film side is the actual front surface mirror. I'll usually take the film and peel up sections of it, then fold it onto itself so it sticks in a center pile. I can then handle the mirror with this plastic tab, push down there if need be for installation, etc. Then just peel the blue film off completely.

His mirrors have a protective top coat of some sort that reduces oxidation and such (this is standard for optical mirrors these days). Although you should try not to touch the front surface mirror, if you do it can be very gently wiped with a cleaner like naphtha.

 

[Jerevan]

dbailey,

good to hear! 🙂 Report back on the progress, I am curious to see how it all looks.

 

[sevo]

The only exceptions I've encountered are a few ancient large format SLRs which used rear surface mirrors.

And even there, chances are that that is due to a later crude DIY repair - a rear coated mirror angled at 45° creates a very prominent double image and makes focusing really hard.

The few rear coated mirrors I've seen on LF SLRs were coarsely cut or broken into shape, and unlikely to have been a manufacturer part. Even the pre WWI SLRs that I own all have a front coated mirror if they are in original condition - often faded to invisibility, as that was in the era prior to vapour coating, when they had to use chemically deposited silver, with a thin shellac paint coat that provided no good protection against oxidation.