cleaning film rails

[brucemuir]

Hey everyone,
I recently acquired a cosmetically clean Nikon F but the film guides have some crud on them.

Best I can surmise is film was left loaded in the camera for a loooonnng time
and some emulsion has adhered to the film guides.

I tried cleaning very carefully with isopropyl and a q tip to no avail, so I
need to either go to a stronger solvent or buff it off somehow without damaging
the smooth rails.

Film transport is fine but it does scratch outside the image area and that cant
be good even if the image is unaffected.

I posted this to the Nikon repair yahoo group but it's a generic repair/problem and things move slow sometimes over there.
Any recommendations?

Thanks,
Bruce

 

[Pgeobc]

Emulsion should be water removable. Part of your removal strategy will be to rehydrate the emulsion and soften it, after which it can be wiped with a cloth.

Being careful to keep fluid out of the mechanism, simply ease it off with a water based cleaning solution. Maybe even just plain water, but I think that distilled water with a drop or two of dishwashing detergent would speed things up. When done, wipe with a cloth dampened with clear water to remove soap residue. Dry as needed.

Keep your hands off the shutter at all costs.

 

[brucemuir]

That's an interesting idea Pg.
I guess when I used isopropyl it just dried it further.

I set the shutter to T when I first tried and barely used any fluid.
The shutter area does indeed make me paranoid.

There is some of this gunk just past the film gate so I can work in that area safely and move to above/below the film gate if it works.

I'll try posting a picture shortly, it looks pretty bad and the only reason I think it is emulsion is there are faint sprocket holes visible.

 

[resummerfield]

Several years ago I acquired a Pentax Spotmatic with contamination on the film rails. This appeared more like corrosion than emulsion, but I’m not sure what it was.

I found a very rigid and sharp piece of metal that was wide enough to span BOTH film rails. In my case, I used the blade from a wood-working hand plane. By spanning both film rails, I hoped to keep the surface of the film rails parallel. I “pulled” this blade back and forth over the rails to smooth them, always pulling the blade in the direction away from the sharp edge, to avoid nicking or cutting the film rails.

I was unable to completely remove this corrosion, but I did smooth the rails so that the film was not damaged or scratched in use.

 

[Worker 11811]

I'm with Pgeobc.

Emulsion should be water soluble. A sponge saturated with hot water mixed with a little bit of soap should get the emulsion off, if it is indeed emulsion. Then clean up with a plastic scraper.

Once clean, follow up with trichloroethane or carbon tet if you can get it. (Highly regulated due to environmental laws.) If you can not get those ethyl alcohol or denatured alcohol will do but be sure to keep the chemicals away from any plastic, leather or other sensitive parts. Acetone is sometimes used to denature grain alcohol and that will dissolve things if you are not careful.

This is how we remove emulsion and debris from movie projector trap rails.

If it is rust or corrosion from some other source, I'm not sure what to do. I would carefully scrape to get down to the bare metal then try to determine if the rails, themselves, are corroded or if the corrosion came from another part in the camera. I can only guess what to do from there.

 

[CGW]

I'm with Pgeobc.

Emulsion should be water soluble. A sponge saturated with hot water mixed with a little bit of soap should get the emulsion off, if it is indeed emulsion. Then clean up with a plastic scraper.

Once clean, follow up with trichloroethane or carbon tet if you can get it. (Highly regulated due to environmental laws.) If you can not get those ethyl alcohol or denatured alcohol will do but be sure to keep the chemicals away from any plastic, leather or other sensitive parts. Acetone is sometimes used to denature grain alcohol and that will dissolve things if you are not careful.

This is how we remove emulsion and debris from movie projector trap rails.

If it is rust or corrosion from some other source, I'm not sure what to do. I would carefully scrape to get down to the bare metal then try to determine if the rails, themselves, are corroded or if the corrosion came from another part in the camera. I can only guess what to do from there.

If they're sticky, clean 'em. If they don't come clean, leave 'em. If it's just discoloration, I'd forget scraping anything. If the rail surface is smooth-ish, why bother?

 

[brucemuir]

this is what I'm working with.

Cgw,
It is outside the image area but scratching the emulsion and I thinking over time I don't want that scraped off emulsion getting in the shutter pulley etc.

 

[CGW]

this is what I'm working with.

Cgw,
It is outside the image area but scratching the emulsion and I thinking over time I don't want that scraped off emulsion getting in the shutter pulley etc.

Ugh...Can only think if you try scraping, make sure what you use is softer than the film rails. Marks on the shutter foil? Looks like someone's already tried.

 

[brucemuir]

Scraping will be my last resort.
I was hoping buffing somehow but then there is all the dust etc.

Yea, I never noticed the shutter marks, looks like someone squiggled a pencil eraser on the curtain.
Crazy the stuff flash can pick up.

I picked this up off the bay of course and need to evaluate if I should return it.
It's a drag cuz the exterior is perfect.

 

[Diapositivo]

Bruce, what I do in this case is to send the seller pictures of the problem and demand a partial refund, or restitution and total refund, at its choice. In this case I would demand $20 for proper cleaning by a professional (or, to state it properly, for contribution toward a CLA by a professional).

My general policy is to bring an old second-hand camera to a professional for a CLA in any case, that will cost $50 - $60, so the extra problem only means some extra $20 or $30.

I had this problem twice, and in both circumstances the seller refunded what I had requested. If the rest of the camera is in good condition I always prefer to solve the question amicably and cheaply.

Fabrizio

 

[brucemuir]

Fabrizio.
The seller is being agreeable discussing options.
It just struck me as odd because he did describe another tiny flaw that would hardly be noticeable.
He seems not to be a typical "vintage" camera seller in this regard.

I will give it some more thought before I even try to remove it myself.
I may just return it because the shutter curtains are starting to bug me even though I do have another F that has a small crinkle in the foil but works fine...

 

[CGW]

Fabrizio.
The seller is being agreeable discussing options.
It just struck me as odd because he did describe another tiny flaw that would hardly be noticeable.
He seems not to be a typical "vintage" camera seller in this regard.

I will give it some more thought before I even try to remove it myself.
I may just return it because the shutter curtains are starting to bug me even though I do have another F that has a small crinkle in the foil but works fine...

With respect, I'd just send it back. Though cosmetically pretty--which matters to me, too--it's not free of functional issues. That's a deal breaker for me.

 

[Worker 11811]

If your trap rails are smooth and dimensionally correct with no pitting, etc. I wouldn't worry about it.

Film has to move across the trap of a movie projector 86,400 times per hour and it has to do that 12 hours per day, 7 days per week for years on end. A still camera does not need to withstand that kind of abuse. A little discoloration on the rails of a movie projector is common and, if it is minor, will not hurt. I can't imagine how a little discoloration like that would affect a still camera in the least. Again, this assumes that there is no pitting, nicks or other damage.

Would you send the camera in for CLA anyway? You could ask the seller to pay for part of the cost.

I've seen cameras and movie projectors that look worse and still produce good images.

 

[richard ide]

Try putting a strip of rolled up TP dipped in water on the affected section of rail and let it sit for a half hour or so. Then take a piece of plastic (i.e. credit card) and scrape the rail. Probably best if you cut a strip of thin cardboard to tightly fit between the rails to cover the shutter opening.

 

[vpwphoto]

Windex on a q-tip. NEVER scrape. If it doesn't go away with a few attempt just leave it, it might be tarnish of some sort or wear...

 

[Worker 11811]

I use a guitar pick to scrape the crud out of projector traps.