Compur-Rapid cleaning woes

[Geoffrey Poulton]

I am no expert in this subject but just want to say when I lived in Pittsburgh, Pennsylvania USA back in the '70s I knew a fellow who owned a camera repair shop who swore that molybdenum was the best lube for a shutter. He said it was a "dry lube" so did not attract dust and dirt and (of course) did not dry out or gum up like oil-based lubes will.

I thought I would leave this information here, which has worked well for me this year.

I had three synchro compur shutters which were stuck. I removed the lens and carefully sprayed either side of the cocking lever with silicone spray.

The shutters having been working properly now for the best part of a year without sticking or hesitation.

On one of the shutters the silicone reached the shutter blades, but had no detrimental effect at all. I think the shutters had been idol for years and years when I bought them, as the optics were perfect, so in these cases a lack of lubrication seems to have been the problem.

It was my intention initially to send them away for servicing, and using the silicone spray was a "nothing ventured, nothing gained" attempt at getting them up and running. I'm glad I did.

I tried the same process on a Prontor shutter, but did not have a positive outcome with that.

[Michael_qrt]

The Learn Camera Repair website (and associated Facebook group) is a great resource for learning how to fix and service things properly https://learncamerarepair.com/. It's run by a few professional repairers or retired professionals I believe and contains lessons, tutorials, general repair info and many service manuals.

[Geoffrey Poulton]

Thanks Mike for this contact.

The reason I tried silicone spray (with substantial success) was because I had three shutters which needed attention. That would have been a fair sized bill for all three, and I wanted to get on with taking pictures.

I've been really pleased with the result on all three Compur shutters, not happy with the Prontor response to the silicone spray.

The site is great.

[Bob Salomon]

Thanks Mike for this contact.

The reason I tried silicone spray (with substantial success) was because I had three shutters which needed attention. That would have been a fair sized bill for all three, and I wanted to get on with taking pictures.

I've been really pleased with the result on all three Compur shutters, not happy with the Prontor response to the silicone spray.

The site is great.

But if any of that spray landed on the shutter blades it would effect their timing.

[paulbarden]

But if any of that spray landed on the shutter blades it would effect their timing.

And its only a matter of time before the silicone will attract dust and start gluing things together. There are many parts of a Compur shutter that are designed to run DRY.

[LabRat]

And its only a matter of time before the silicone will attract dust and start gluing things together. There are many parts of a Compur shutter that are designed to run DRY.

The problem with old shutters is they are supposed to run dry and usually not lube failures, but what happens is a fine layer of oxidation builds where metal meets metal, and tends to be slightly "sticky" preventing totally free movement... The oxidation needs to be carefully manually removed...

Steve K

[Geoffrey Poulton]

Thanks Steve and Bob, I'm hoping that the movement which the silicone has made possible, will clean the surfaces through usage. I hasten to add that I know only a little of the inner workings of shutters!

The timings sound about right to my ear at present, and watching the second hand on a clock, the 1 second speed looks to be accurate on all three shutters, so I'm keeping my fingers crossed, but have taken on board all the advice given here.

I did at least clean off the silicone that reached the blades of one of the shutters. I put a very small amount of the silicone in the area of the slow speed escapement, the use of the word "spraying" sounds a bit reckless for what I actually did!! So I'm hoping for the best!

Shutter servicing in the UK seems to be quite an item.

[John Layton]

Given the extremely high speeds reached by the shutter blades, I'd be very careful about risking the depositing of liquids onto these blades...as this would then place adjacent lens elements at risk. Make sense?

As for lubricating a shutter...I've had good luck with a bit of watch oil or sewing machine oil, carefully/sparingly applied to pinions with a toothpick. Modern Copal slow speed mechanisms are relatively easy to remove (three screws to remove), after which the entire "cage" can be dunked in alcohol, followed by re-lubing of pinions with a toothpick as just described.

Takes a bit of patience (and lots of fingers!) to re-assemble...but very worthwhile!

[Geoffrey Poulton]

Thanks John,
Thankfully the shutter blades are all dry, I used only as much as I needed to unstick the shutters in the are of the slow running escapement, and I'm hoping they will continue operating. I put in the silicone about 7 or 8 months ago and everything is working nicely still. I hoping it continues.
One day I will take a shutter apart to clean and lubricate it, and try not to break it!!