Thread lubricant?

I just acquired a 100-year old Rapid Rectilinear triple convertible lens, and I'm a bit concerned about screwing the various elements in and out to convert the lens. The barrel is made of brass - a somewhat soft metal.

I know the dangers of getting oil, etc. on the lens glass, but I'm wondering if some of the more modern lubricants might be good for the threads and not migrate to the glass itself. Any ideas?
juan

Lube...

juan said:

I just acquired a 100-year old Rapid Rectilinear triple convertible lens, and I'm a bit concerned about screwing the various elements in and out to convert the lens. The barrel is made of brass - a somewhat soft metal.

I know the dangers of getting oil, etc. on the lens glass, but I'm wondering if some of the more modern lubricants might be good for the threads and not migrate to the glass itself. Any ideas?
juan

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Do the threads bind? If not, I would probably avoid it. I would just take extra care threading and unthreading. However, you could try some dry graphite powder, applied sparingly to the threads, rubbed in, and wiped off. If that doesn't work, I can give you some info on greases made specifically for inside lenses.

Thread lubricant? A mention of digital will usually get the thread moving quickly.

While you might want to clean the threads with a bit of alcohol or naptha applied to a cloth that will compress into the threads when you wipe them down, I wouldn't actually lubricate external threads on the lens components. Lubricants tend to attract dirt and grime, which over time would do far more harm to the threads than normal brass-to-brass wear.

How about teflon tape??

Juan,
Use canning wax, rub the male thread lightly against the block of wax. It takes very little doesn't spread & leaves no noticable residue.

I have dozens of these and haven't worried about this so far.

I have never felt the need to lubricate the threads on my lenses, even my convertables.

Dave

HenceForthWith said:

... you could try some dry graphite powder...

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Graphite is a powder and will always remain a powder. It is very stable and will find its way into places you don't want powder, such as between elements, onto film, etc. I have been very successful keeping graphite away from any of my lenses. On the other hand, there is a stable lubricant which stays put and is very readily obtained, and that is Lubriplate. It is used on automobile engines during assembly, comes in a tube with a small spout, and LITTLE dab will do ya. I used it on gear rails and gears, but have only used it once on a lens--the flange for my Wide Field Ektar was a little out of round, and it helped screw the lens down completely.
Like Shaggy, I have used paraffin or even soap with good results.

juan said:

I just acquired a 100-year old Rapid Rectilinear triple convertible lens, and I'm a bit concerned about screwing the various elements in and out to convert the lens. The barrel is made of brass - a somewhat soft metal.
...

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Brass threads? No lubricant. You're not going to wear the threads in any measurable sense simply by interchanging the elements. Keep it clean. Cleanliness is next to godliness and resale value.

wfwhitaker said:

Cleanliness is next to godliness and resale value.

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For the former that may be true, which is good to know because according to Nietzsche faith ain't going to get it:



HenceForthWith that is a great signiture!

As for the question I agree with a few of the others: get it clean, keep it cleanand carefully remove any burs. Teflon tape would be good if you wish to seal the air inside, but probably would not otherwise be helpful.

Thinking about this some more after DE brought up lubriplate. At work I have dozens of movie magazines that I am in charge of. They hold 1200 feet of 35mm film and are opened and closed with a thread. Picture a 12" disc with threads. Well before I got there some %*&(_() sob lubed them with lubriplate. After time, that stuff turned to (sitting several seconds trying to think of an adjective to describe this stuff....). Anyways it ain't nice and I have a devil of a time to this day with a few of them. I cleaned them with pencil lead. Sharpen pencil, put deep in thread V and rotate with pressure until the dried up goo is gone. Pencil lead is graphite and actually leaves a very dry very slick residue. Most of my big lids can be spun effortlessly now. Give it a try. Can't beat the price. Most of my pencils are stolen.

Thanks, guys. I'll try a through cleaning first.
juan

Deckled Edge said:

Graphite is a powder and will always remain a powder. It is very stable and will find its way into places you don't want powder, such as between elements, onto film, etc. I have been very successful keeping graphite away from any of my lenses.

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Yes, if you dump a large quantity in a lens you will have problems. The key is to know what you are doing: get the finest graphite you can find, put a tiny amount in the lid of a 35mm film cannister. Take a Q-tip and roll it in the graphite. Apply it sparsely with pressure. Take several other Q-tips and clean off any visible graphite. Now you are left with graphite particles in the pores of the brass.

I just repaired a cine lens (I'm a lens tech in the movie biz) and employed this method. Works great. I'll have to try the pencil trick! Thanks Jim...

Deckled Edge said:

On the other hand, there is a stable lubricant which stays put and is very readily obtained, and that is Lubriplate. It is used on automobile engines

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That would be a big mistake. As pointed out, that will eventually gum up and make a huge mess. The key term here is "automobile engine"--keep that stuff away!

I have lens grease from Zeiss, Canon, and Fuji. They are very specialized--and you won't find them on automobiles!

mrcallow said:

For the former that may be true, which is good to know because according to Nietzsche faith ain't going to get it:

A casual stroll through the lunatic asylum shows that faith does not prove anything. ​

HenceForthWith that is a great signiture!

As for the question I agree with a few of the others: get it clean, keep it cleanand carefully remove any burs. Teflon tape would be good if you wish to seal the air inside, but probably would not otherwise be helpful.

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Thanks--I did philosophy in college and have been reading him ever since. It isn't easy reading and I don't agree with everything he wrote--but on faith, I'm with him 100%...