Lens stuck in mount

Akki14 · Jun 14, 2007

My enlarger lens is stuck in the lens mount for my enlarger. It isn't crossthreaded but it was put in the enlarger way back when it was a bit cooler weather and I'm wondering if that has something to do with it. I've put a few drops of WD40 on the thread from the inside (popped out the mount so I could get to the other side to do this) and left it overnight - hasn't helped.

I don't really want to do this but it's come to my mind that maybe sticking it in the freezer would help. We already tried warming the mount separate from the lens to try to loose it and that didn't work either.

I have a bad feeling I might need to be looking for a new mount for the enlarger if I ever want to print medium format again Then I'd have to be swapped the mounts with the lenses attached...

Nick Zentena · Jun 14, 2007

You might want to tell us some more-)

Does the lensboard use a retaining ring? Is the ring stuck?

Or is it threaded?

If the enlarger isn't rare having multiple lensboards isn't a bad thing.

Akki14 · Jun 14, 2007

Enlarger lens and thing it's stuck/screwed into:
http://www.stargazy.org/photos/enlargerlens1.JPG

Enlarger where the round thingy and the lens goes:
http://www.stargazy.org/photos/enlargerlens2.JPG

This is the first enlarger I've ever owned, I've only ever used enlargers set up for 35mm before this and when I bought this one, it came preassembled and came with instructions for assembly in german anyway:confused: It's an LPL C7700MX

Nick Zentena · Jun 14, 2007

Recessed board? What does the back of it look like? Is there a ring?

Neal · Jun 14, 2007

Dear Akki14,

Having your lenses on separate mounts can make it easier to change them in and out. On my enlarger it's almost a necessity.Personally, I would keep the lens out of the freezer and avoid further applications of oil.

Neal Wydra

David H. Bebbington · Jun 14, 2007

A couple of guesses: If I have viewed the pictures correctly, the lens AND the panel are made of light alloy. This can lead to 2 problems:
1) Electrolytic corrosion between the 2 components - in a sense, the two weld themselves together
2) Susceptibility to distortion by physical pressure (such as squeezing components while trying to unscrew them). This distortion makes the screwed connection grip all the harder.

If problem 2 applies, the best chance of separating the 2 components would be to put the panel back in the enlarger, so that it is gripped evenly all round, wrap a rubber band round the lens and try to turn this applying as LITTLE pressure as possible, preferably using both hands to make the pressure as even as possible.

If the lens is really stuck, then really your best bet is to buy another panel. I am mindful of one time when I tried to remove a light alloy spark plug from the light alloy head of my Briggs & Stratton lawnmower, where electrolytic corrosion was present. Using only normal pressure with a spark plug wrench, I "unscrewed" the plug plus a ring of surrounding metal from the cylinder head - the corrosion had made a weld-like bond which was stronger than the cylinder-head material itself. I think if you apply any real force to your lens, you will wreck it and the panel!

Regards,

David

TimVermont · Jun 14, 2007

If you decide to try the freezer option, I'd first _gently_ warm the lens and mount with a hair dryer to drive off any moisture present. Then wrap it in a couple of zip lock bags before putting it in the freezer. Good Luck!

Richard Kelham · Jun 14, 2007

This is not the first LPL C7700 I've come across with this problem. As David Bebbington says, it's probably electrolytic corrosion as the lens mount is definitely alloy (not sure about the lens): buy another lens panel is the best answer! It makes lens changing quicker and simpler even without the corrosion.

Richard

bdial · Jun 14, 2007

You could try some PB Blaster from the auto parts store (http://www.pbblaster.com/store/moreinfo.cfm?Product_ID=1). It's supposed to be a more effective thread penetrate than products like WD-40. Lots of mechanics swear by it. I'm not sure but it is probably only available as an aerosol, so I'd spray some into a container of some sort and apply it with a q-tip or small brush. Apply it, then wait several hours, then try unscrewing the lens.
Otherwise, it sounds like a good excuse to buy another lens board.

Jon Shiu · Jun 14, 2007

Hi, was wondering how you are gripping the lensboard and lens to unscrew. It seems like there is not much to grip? Perhaps just needs a bit of leverage such as strap wrenches or rubber gloves etc. Corrosion seems doubtful if it has only been screwed in for a few months.

Jon

Ed Lefkowicz · Jun 14, 2007

Try this

Corrosion is a likely guess. Try this: vibrating the assembly might work enough of the WD-40 into the threads to penetrate and loosen it. (My father was a machinist, and on less delicate assemblies, he'd often repeatedly tap a stuck nut with a hammer to vibrate the penetrating oil in. This was pre-WD-40 days!) So you could try putting it on something that shakes a lot; or sit down, watch a movie, and tap, tap, tap away with a rubber mallet for an hour or two. Then try again. Nothing to lose, and it might work.

resummerfield · Jun 14, 2007

Akki14 said:
.....maybe sticking it in the freezer would help. We already tried warming the mount separate from the lens to try to loose it and that didn't work either......

I think you are on the right track. Freeze the assembly, then use a hair dryer to heat the lens board. Then secure the lens board, either in the enlarger or something like a strap wrench, to avoid uneven pressure. Try to twist the lens by hand pressure, covering it with something like a rubber sheet for grip.

Good luck!

Cliff · Jun 14, 2007

appliance cord

Do what Eric suggested and use an appliance cord or lamp cord.
Appliance cord works better. Print dryer or ironing cord.
Use one that feels like soft rubber. Works good on lens filters.

pnance · Jun 15, 2007

Remember: cooling shrinks, heating expands. So freezing will only make it tighter. However, I would be very cautious about heating as well. You would need to get it quite hot to get an appreciable expansion.

Akki14 · Jun 16, 2007

It can't be corrosion - it's only been gently screwed in for a month or two(since April, actually). I had been swapping the lenses around no problems before that. I realise freezing/cold shrinks which is why I thought it'd cause the metal around the lens to shrink down more than the outer metal. I have been using rubberbands and a jar opener to get purchase on it to grip it.

No clue how hard it's going to be to find a replacement ring AND I'm under pressure to finish printing a friends' wedding photos and I only had two rolls of 120 film to print left

pnance · Jun 16, 2007

Looking at the first photo again, have you tried gripping the part that is projecting through the mount? And are you sure you turned in the correct direction?

Jon Shiu · Jun 16, 2007

Time to use the brute force method.

Jon

David H. Bebbington · Jun 17, 2007

Akki14 said:
It can't be corrosion - it's only been gently screwed in for a month or two(since April, actually).(

In the words of the great (albeit fictional) S. Holmes:
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth!"

In your case - if it AIN'T corrosion, which has created a weld-like bond, what else could it be? If you REALLY have to separate the lens and panel, try increased force, but be prepared to damage both components beyond repair!

Akki14 · Jun 17, 2007

pnance said:
Looking at the first photo again, have you tried gripping the part that is projecting through the mount? And are you sure you turned in the correct direction?

Yeah that part turns too easily and I think that just unscrews the rear elements of the lens so I've been avoiding unscrewing that part completely as I know nothing about reassembling a lens. I did momentarily screw it in worse (doh!) because I forgot which direction but also that moved a bit in that direction and not in the unloosening direction :confused:

I'm not sure how much more force I can get on the @#%& thing. I've already tried unscrewing it and my husband has too.

bdial · Jun 17, 2007

...I forgot which direction...

Here's a mnemonic that may help...
Righty - Tighty, Lefty - Loosey

Works for most things, but not all

As for the lens board, and lens, I think I would start shopping for another board to mount the 50 in. There are tools for plumbing that could maybe grip then lens near the board to allow you to use more force, but would surely do considerable damage to the lens in the process.
I've encountered situations on automobiles where frozen steel bolts simply shear off, leaving the threaded portion in. The aluminum components you are dealing with cannot stand anywhere near the force that steel can.

Akki14 · Jun 17, 2007

Yeah I was doing righty tighty but because the lens is up and facing the opposite way, when it's in the enlarger it's more like lefty tighty righty loosey...

I tried the freezer trick and it worked perfectly (woohoo!) unscrewed with no effort at all... except for now i have a bit of condensation but it's better than nothing or having to find a needle in a haystake looking for another recessed thingy for the enlarger. I'll just go find some silica gel and a box to stick it in since I don't need that lens immediately. I'm a strange girl, I don't own a hairdryer. I'm thinking I may have to purchase a small one just for oddjobs rather than drying my hair.

bdial · Jun 17, 2007

This is good news, contratulations, especially on beating all our dire warnings!

For the future, a tiny dab of anti-seize lubricant might help, here's one example, http://www.permatex.com/products/au...ubricants/Permatex_Anti-Seize_Lubricant_a.htm
For the lens you'd only need enough to fill an "O" however. But it is useful for other stuff.

Also, the lens only needs to be tight enough to not move around when you adjust the f-stop.

Nick Zentena · Jun 17, 2007

Hair dryer is great in the darkroom. If you do colour it's a lot more fun then waiting for test strips to dry.

Jon Shiu · Jun 17, 2007

Congrats!

I remember not being able to get my B1 head off my Gitzo 1228 column. After putting them in the freezer for a short time they unscrewed by hand very easily.

Jon

max_ebb · Jun 18, 2007

Glad to hear that you successfully separated the lens from the board. Two things I would like to point out for anybody that does anything like this in the future:

1. WD40 is NOT penetrating oil (and it's also not a very good lubricating oil). It is one of the most useless products on the planet as far as I'm concerned. Decent penetrating probably would have done the job without having to use the freezer.

2. Putting it in the freezer is not what causes the condensation. Taking it OUT of the freezer is what causes condensation. The way to avoid condensation on something when you take it out of the freezer is to not let it warm up too fast. Wrap a towel around it while it's in the freezer (so the towel is also cold), and move it to the refrigerator for a while before putting it in room temperature (keeping it wrapped in the towel).

The problem was most likely electrolytic corrosion from dissimilar metals being in contact with each other. It just wasn't very bad yet. If you live close to the ocean where there is salt in the air, electrolytic corrosion happens much faster. It doesn't matter if either of the metals is an alloy. Electrolytic corrosion can happen when any dissimilar metals are in contact with each other (aluminum and steel for example).

Lens stuck in mount

Attachments

Privacy & Transparency

Privacy & Transparency