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Edsprake
Tinkerer
Username: Edsprake
Post Number: 1
Registered: 07-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 12, 2012 - 03:53 am: | 
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Apologies if this is a somewhat newbie question, I've just come into possesion of a few very well used vintage cameras and was after some first time advice.
The Retina version 118 I have has clearly been very well used indeed and the spring plate that holds the film flat in the film compartment has had a lot of the original black paint rubbed away.
I assume that this will potentially affect picture quality as you will get the reflection of light from the silver metal back through the film, giving almost a redscale effect. I've not put a film through it yet though, so I don't know.
I was just wondering what would be the best method of restoring the black finish to that part of the mechanism would be.
Any help and suggested reading for the basics of resoration would be very gratefully appreciated!
Thanks,
Ed
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Glenn
Tinkerer
Username: Glenn
Post Number: 1031
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 12, 2012 - 06:35 am: |
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Most of the pressure plates I have come across are not painted, they are blackened by some form of chemical process - adonising if alloy or chemical blacking if steel. If yours is steel just go and buy a small tube of gun blue/black from a gunsmith - if you can find on in the UK! There used to be alloy and brass blackening products available in past times - model engineering suppliers used to sell them in small tubes or bottles. Try a Google search - in the 50's and 60's certain 'hobby' mags were full of DIY kitchen sink formulae for blackening all manner of metals. |
Edsprake
Tinkerer
Username: Edsprake
Post Number: 2
Registered: 07-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 12, 2012 - 09:19 am: |
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That sounds good, I shall have a search.
I was suggested by one of the engineers at work to take the pressure place back to metal then do a couple of thin coats of matt black paint followed by lapping paper to ensure a smooth coat, not sure that it would be as durable though?
Thanks ever so much! |
Glenn
Tinkerer
Username: Glenn
Post Number: 1032
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 12, 2012 - 09:56 am: |
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If the plate is alloy there are small home anodising (fingers hit keys in correct order this time!) kits available, but the dying process might be beyond kitchen sink chemistry. Still it may be worth a search online, the dying of a clear anodised surface is not a complicated process in industry. |
Hollenbj
Tinkerer
Username: Hollenbj
Post Number: 70
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 12, 2012 - 11:23 am: |
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I'm following this thread with anticipation. I too have worn film pressure plates.
I've seen the results of gun bluing and it's not terribly black. Probably enough for our purpose, but the original plates are definitely "black".
I hope someone has a good suggestion here. |
Edsprake
Tinkerer
Username: Edsprake
Post Number: 3
Registered: 07-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 13, 2012 - 04:02 am: |
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I was in the shop that I get my film processed by yesterday and was chatting to one of the guys who's been doing this for years, and apparently a worn pressure plate would have caused more problems back in the 30's than it would now as current film has a coating on the reverse which is designed to stop light coming through from the rear (to a certain extent...). I guess that's part of the reason why you have to expose a couple of stops over when redscaling film at home?
I'm thinking that I might just run a film trough it first to see what effect (if any there is) rather than tinkering without knowing whether it's making a difference first.
Of course there is always the potential that if the coating isn't smooth, you can scratch the film surface...
Might be a little time, but I'll let you know how it goes when I find out! |
Finnegan
Tinkerer
Username: Finnegan
Post Number: 189
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 13, 2012 - 12:54 pm: |
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I like the "strip it to bare metal and repaint" idea. The black on these Retinas look like paint to me. |
Fallisphoto
Tinkerer
Username: Fallisphoto
Post Number: 276
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 18, 2012 - 10:41 am: |
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Well, if it's paint, I'd use epoxy paint. Epoxy paint doesn't require baking to harden it, like enamel does and it dries really hard. You need to be careful though, and don't make mistakes, because once epoxy paint dries, the only way to get it off is to grind it off. |
Mr_flibble
Tinkerer
Username: Mr_flibble
Post Number: 90
Registered: 10-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 19, 2012 - 01:38 am: |
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Ed, you're right, most films these days have anti-halation layers that prevent/reduce light from passing through the base layer and reflecting off the film pressure plate.
Lucky film is one with a poor anti-halation layer, the result is blown highlights with brightly lite subjects.
I don't expect it will influence your photos much, as in the 1930s and 1940s Kodak 35 cameras had unpainted metallic pressure plates. |
