Film-Tech Forum ARCHIVE: Repair Cement For Lens

This is topic Repair Cement For Lens in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tony Gallimore (Member # 5358) on 11-19-2009, 09:43 PM:

I was hoping some of you gents could direct me to a source for lens cement or someone who would perform the repair for me. I understand some types of cement have a hazardous materials rating and are very costly to have shipped. I have a Kollmorgen Hi-Lux Variable Anamorphic Lens that was in storage for about ten years. During that time the cement yellowed and crumbled. I discovered this when I removed it from storage and disassembled it for cleaning. Since this is one of a matched pair, I would like to repair it and return it to service. Any ideas or information from you guys sure would be appreciated. Thanks!

Tony

Posted by Tim Reed (Member # 137) on 11-20-2009, 12:35 AM:

I was going to duck and cover, until I saw in your profile you're putting together a home screening room! [Wink]

I would think Schneider could do the work, but it won't be cheap.

Btw, I have an old Hi-Lux variable from my hometown drive-in, that was used there when I was a kid. It's a paperweight on my desk, and I will never part with it. [Smile]

Posted by Monte L Fullmer (Member # 2797) on 11-20-2009, 05:03 AM:

...and you may have to make contact with a booth supply dealer to make arrangements for lens repair since the lens manufacturer usually won't deal with customers directly.

...Just a protocol these people uses..

Good luck-Monte

Posted by Frank Angel (Member # 248) on 11-20-2009, 05:24 AM:

Tony, it sure would be easier and a lot cheaper to buy a used anamorphic, unless you have a specific need for the Hi-Lux's ability to vary the expansion ratio. If not probably for the cost of the cement you can get a lens that will not be such a light hog and with better resolution.

Is there a need for the variable? If you project an SMPTE hatch test film (can't recall the PA number off hand), you will see that those variables don't vary evenly across they frame. They can have more stretch on one end than the other.

Plus, unless you have some hands-on experience in lens manufacture, I wouldn't try glueing the elements yourself. The manufacture has equipment that can apply a micro thin layer of glue evenly across the lens that you can't do by hand with a brush. Unless you just like to tinker.

Lastly, unlike Tim, there are plenty of used theatre equipment dealers who WILL part with their Hi-Lux paperweights for a very reasonable cost I'm sure.

Posted by Scott Norwood (Member # 30) on 11-20-2009, 07:51 AM:

Have you tried asking a place that repairs cameras? Most of them will work on lenses, although they probably have never seen anamorphics before. It's worth asking, anyway.

Posted by Mark Gulbrandsen (Member # 72) on 11-20-2009, 09:42 AM:

It is not worth repairing. Having Schneider repair it would cost more than a good used late model anamorphic bought off of e-bay. The elemments in an anamorphic have to be aligned to with in .01deg for the image to be sharp.

Posted by Louis Bornwasser (Member # 3063) on 11-20-2009, 12:00 PM:

50%+ light loss in a new Hi-Lux. I may well have one for you.

Oh Ya, yellow color at no extra charge. Mr Hadden must have sold 100's of these. Louis

Posted by Tim Reed (Member # 137) on 11-20-2009, 12:56 PM:

Louis, I think Mr. Hadden sold the one I have. It was from Sky-Vue, Winchester.

Frank, my love is purely for sentimental reasons. [Razz]

Posted by Gordon McLeod (Member # 33) on 11-20-2009, 02:34 PM:

Edmond Scientific optical division used to sell Canadian Balsam cement
I am not sure what the companies name is now

Posted by Pete Naples (Member # 761) on 11-20-2009, 03:17 PM:

I was once told by a man who worked on Submarine periscope optics that (IIRC) perspex dissolved in Acetone was what they used.

I don't know about the US or Canada, but here you'd have the devils own job trying to obtain Acetone these days.

Posted by Jeff Taylor (Member # 443) on 11-20-2009, 04:22 PM:

here they sell it for $2 in any hardware store (acetone)

Posted by Randy Stankey (Member # 64) on 11-20-2009, 04:49 PM:

Canada balsam cement: http://www.surplusshed.com/pages/item/b1077.html

I would look at this more like a science project than as a repair project.

Use it to study how lenses work rather than a way to rejuvenate an old lens. As the others say, you are unlikely to find anybody to repair it unless you want to pay big bucks. The equipment needed for you to do the job would also be prohibitively expensive. Unless you have some kind of attachment to those lenses, it would pay you just to get new ones.

However, if you realize that the lens won't work the way it is you will see that you have almost nothing to lose by trying to repair it yourself. If you break it, you haven't lost anything. If you get it back working, even reasonably well, you are ahead of the game. And, in the process, you will have learned something about lenses and how they work.

Look at it that way and you have everything to gain and nothing to lose.

Posted by Pete Naples (Member # 761) on 11-20-2009, 04:54 PM:

Not here! You could once upon a time buy it readily but nowadays anything vaguely useful is banned less you drink it and die.

Carbon Tetrachloride, beloved solvent of horologist. Can't get that because it causes cancer if you immerse yourself in it. Easy answer is not to be a dumbass and get it on your skin, but no, the Orwellian government of the UK banned the stuff.

Methylated Spirits, it's flammable and poisonous if consumed. When I was a wee boy we used it for powering model steam engines and camping stoves. Can't buy it in a chemists shop now but go down the road to the local outdoors emporium and you can buy it by the gallon [Roll Eyes]

Acetone is pretty much unobtainable now unless you're a lab. Last gallon I got came from France, where you can buy it in the supermarkets. I'm waiting for the knock at the door after posting that I have Acetone...

Great Britain, where you have to have a licence to get married, own a gun, drive a car, watch TV or carry out electrical work in your own home. Oh and be vetted to drive your relatives/friends/neighbours children to school scouts, football etc. About the only thing uncontrolled here is breeding. You couldn't make it up. Drive 3mph over the limit and you'll be prosecuted. Shoot a burglar in your home and you'll go to jail. Commit rape and you'll probably never be caught.

Will the last man to leave the UK in disgust please remember to turn the lights off? Probably lights will have been banned by then as someone might be offended by their brightness or strain a finger operating the switch.

Posted by Chris Slycord (Member # 4239) on 11-20-2009, 06:10 PM:

Not to be a stickler but per the rules we might want to keep this out of political areas...

Posted by Ian Parfrey (Member # 5122) on 11-20-2009, 06:37 PM:

I'm not too sure that this is particular to the UK.

Very similar things are happening here in Oz, so I guess the only "political" reference would be in the realm of "political correctness" re: mothering of the population and removing their own ability to make common sense decisions.

So, Pete, if it helps- you're not alone.

Posted by Mark Gulbrandsen (Member # 72) on 11-20-2009, 07:52 PM:

The best cement is of course no cement or just use todays modern cinema lenses. Balsam is fine for optics that are not exposed to alot of heat. You've all seen lenses that have been baked by large arc or xenon liht sources. The cement typically used today is a UV curable optical cement. It has much better properties than balsam and lenses re-cemented with the stuff actually improve. The cement also does not yellow over time.

Summers UV Curable Optical Cement

Mark

Posted by Tony Gallimore (Member # 5358) on 11-20-2009, 08:48 PM:

Thanks!! I appreciate every ones input.

As I mentioned initially, the cement source I found here in the lower 48 wanted to stick a huge shipping charge (much more than the cement itself) on it because it's considered hazardous material, at least that particular government version of balsam cement was. I'm not desperate to keep the lens, except in using the variable in my home theatre application, I really would never need to change the lens... just reset it for a flat print and change the aperture plate. Image size wouldn't be a major problem with my setup. Yes, it does sound pretty lame avoiding a thirty second lens change. I guess I became attached to it (the variable) back (in the carbon days) when I was working the cinema in the 70's and 80's before National Screen Service provided trailers in scope. We used the variable very successfully running flat trailers plus back then a cartoon as well as local commercials on film, up against a scope feature. We did a lot of curtain play with it making for a pretty nice presentation. Anyway, THANKS guys, I'll think on it a little more and then probably go for the new anamorphic.

Posted by Tim Reed (Member # 137) on 11-20-2009, 10:52 PM:

quote:
Summers Optical, Hatfield, PA 19440

Practically in my backyard.

Posted by Randy Stankey (Member # 64) on 11-20-2009, 11:04 PM:

The balsam in on the site I found is just a chunk of purified tree sap. I can hardly think of a reason why it would be hazardous. However, you are supposed to break up the chunk of resin, mix it in xylene and heat it until it dissolves. That could be tricky.

Seeing this subject come up inspired me to read up on the subject. There are several sites where people talk about repairing telescope lenses, rifle scopes and camera lenses. I see little reason why a projection lens would be much different.

From what I've read there are two main hurdles to getting the repair right. First, is the proper preparation and application of the cement. Second is getting the glass aligned correctly.

The xylene used to dissolve the balsam is flammable. If you have to heat the mixture to make the cement, that could pose a hazard.

I have also read that you should mark the lenses before you take them apart. Old lens elements are oriented rotationally as well as laterally. Before computerized grinders were invented, there were imperfections which were compensated by rotating the two elements until they aligned. More than one person said that you should mark the lenses before taking them apart so you can get them back into the correct orientation.

I also read that a lot of people still like to use balsam instead of UV curable cement because balsam is easier to remove than the synthetic. If you ever have to rework the lenses, it will be difficult to separate them again after using UV cement. With balsam, you can just drop them in hot water and they should come apart fairly easily.

I'm not saying I'm an expert, here. I'm just telling about what I read.

Like I said, you have nothing to lose by trying.

Posted by Frank Angel (Member # 248) on 11-20-2009, 11:54 PM:

Can anyone explain why older lenses had to be cemented while modern lenses don't? Is it because they can get higher tolerances in the mounting body today so they are held together more perfectly? Just guessing. Seems like a big jump from needing to be cemented together to just being held that way mechanically.

Posted by Bernard Tonks (Member # 809) on 11-21-2009, 03:10 AM:

quote: Pete Naples
I was once told by a man who worked on Submarine periscope optics that (IIRC) perspex dissolved in Acetone was what they used.

I don't know about the US or Canada, but here you'd have the devils own job trying to obtain Acetone these days.

Nail varnish remover seems to be Acetone by the strong smell of it.

Posted by John Hawkinson (Member # 1135) on 11-21-2009, 06:40 AM:

Acetone is the active ingredient in nail polish remover sold here in the US. Probably true in the UK too, though I'm quite surprised to find you can't purchase straight-up acetone at the local hardware store.

Frank, if we take Mark's explanation, it is that modern lenses are cemented with UV-curing cement, which can withstand substantially higher temperatures and doesn't crumble and degrade like the old stuff did. So straightforward advances in adhesive technology.

--jhawk

Posted by Stephen Furley (Member # 1277) on 11-21-2009, 06:40 AM:

It used to be, or at least it used to contain a lot of acetone, but I think they use other solvents now.

Posted by Louis Bornwasser (Member # 3063) on 11-21-2009, 07:29 AM:

Acetone can be purchased by the gallon at any Lowes or Home Depot. Louis