Who can re-cement lens elements?

Here's a place that offers that service:

http://www.focalpointlens.com/fp_intro.html

 

I too would recommend Focal Point. I have had work done by John VanStelton and he is among the very best.

Richard Wasserman

 

I see they also provide anti reflective coating work too, I'll have to book mark them for future work.

 

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Since a lens of that vintage is probably cemented with canada balsam, there is a way to heat the lens, very gradually, in a normal oven; allow it to reach the proper temp (I think it was 350F hold for a time; then gradually reduce to room temp. I did this once with an enlarging anastigmat.

 

I have a pair of Mitchell Baltar primes I sold to a man in China that were returned with separation in the exact same element on each lens. The separation was not there when it left and I have a strong suspicion it was induced by the buyer, who seemed to have buyer's remorse upon winning BOTH lenses in separate auctions!

In any event, one of the lenses mounts has a big ding in it, but Paypal refused to accept the auction pictures as before and the returned lens pix as evidence. Said I could have manipulated them, so therefore, I couldn't be trusted...

Now, 3 months later, I am out $700 USD (they issued a payback refund despite my tons of evidence and objections)AND and a pair of Baltar Primes!

What makes me crazy is the lenses were returned with very well defined and heavy separation that looks suspiciously like someone dipped their finger in a mild solvent and ran it around the elements (middle doublet that is VERY easy to remove).

I cannot believe the temperature variations between here and China during air mail caused the separations.

Regardless, I will never use paypal or Ebay again!

I might try that heating in the oven trick and see if it works; I have little more to loose...

 

cooltouch,
I just use acetone as a solvent for the Balsam. Let the elements sit in the acetone for a few hours or overnight & they come right apart. Any glue remaining on the glued surfaces can easily be removed with a Q-tip & Acetone. Alignment is critical when reassembling Use a pair of "V" clamps "<O>" wood with a notch in the ends works to hold the glass while the glue sets.
I use "Crystal Clear" which is available at Ace hardware, it's around $5 for a lifetime supply. When using it the surface to be glued have to be clean. ONE drop in the center of the concave lens is all it takes. Apply the drop, make sure there are NO bubbles, & gently set the convex lens on the drop of glue. Use the lens to spread the glue evenly by rotating & sliding the two lenses together. The cement will actually hold the glasses together, all you need is the clamping action from the sides. If they're not in alignment, they won't fit back into the barrel. You will need to clean the excess cement from the edges of the elements before they've set. I just use a glossy black spray from the hobby shop to blacken the edges. VERY light coats.

 

I think I might line the V with some felt or something to keep from scratching the lens elements, but it's just a guess since I've never done this type of repair.


Some UV cure glue would be great for this, all you would need to to is take it out in the sunshine to cure it.

 

UV cure cement would be better, or you could just use Canada Balsam again. CB is a slow cure cement, UV cure is A. fast, and B, PERMANENT. Ie, mess up the alignment and it will stay that way. Also, look for scribe marks on the edges of the element before you solvent soak them. It's not uncommon for them to be there to mark proper alignment of the doublet before it is cemented. If there aren't any, mark the edges so you can put them back in alignment. Also check if the two lenses are in cylindrical alignment. They might have been cemented off axis to make them align optically, or maybe they were ground to form a cylinder after being cemented which may have removed the scribe marks.

 

Surplus Shed has chunks of 'Canada Balsam':

http://www.surplusshed.com/pages/item/b1077.html

 

Michael,
That's exactly what I meant by "V" clamps. They don't have to be anything fancy, ply or pine works fine. It just has to be thick enough to keep both pieces aligned not to apply pressure of more than a couple of ounces. I just us small clamps with the squeeze trigger.
I should have mentioned that when I have the elements together I do apply pressure with my fingers initially for a firm bond.
Make sure there's no residue from the cement on the surfaces of the glass. If you use the UV stuff it's imf**king possible to get off.

 

You might try Camtech Photographic Services
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They will do a great job at much less than your other quote ( not to mention your dollar will go a long way up here again)
They did my first Wolensak lens that was totally separated and it is fantastic. Give them an email. Can't hurt

 

Sunlight works just fine.
Sometimes the engineers at Summers and just too specific. For fine, highly critical work you may need that kind of specificity. 90% of the time ,,,,NOT! Kinda like the argument that you need a collimator to reassemble or focus a lens.
The standards to which equipment is made both recently and not so recently make alignment errors pretty negligible. Unless you're the guy that uses test charts and microscopes.

 

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They are in Croydon, south London, England.

 

Good morning, Windscale;

A quick request for a confirmation of an old memory:

Isn't Croydon on the A-26 south "of" London? Or has London grown that far south now?

 

Croydon is in Surrey. But London has stretched out so much in the past few years that many would regard Croydon as south London as one can get there by using a London Transport all zone ticket by train.

 

The dividing line between London and Croydon was hard to find 40 years ago when I lived there.

 

shipped lens separation

I THINK IT HAPPENS WHEN SHIPPED BY AIR IN AN UNPRESSURIZED, UNHEATED COMPARTMENT, SO I ADDED THE FOLLOWING TO THE START OF "MY POLICIES" IN BLACKTHORN AND CURRENT LISTINGS.

LENSES SHIPPED OVERSEAS HAVE SUFFERED SEPARATION OF THE CEMENTED ELEMENTS, ESPECIALLY OLDER LENSES. I SUSPECT IT HAPPENS WHEN SHIPPED BY AIR IN AN UNPRESSURIZED AND/OR UNHEATED COMPARTMENT. THEREFORE, IF YOU BID ON A LENS TO BE SHIPPED OFF THE US CONTINENT, YOU MUST AGREE, BY EMAIL, THAT YOU ACCEPT THE RESPONSIBILITY FOR THE DAMAGE, WILL NOT MAKE ANY CLAIM OR COMPLAINT ABOUT SUCH DAMAGE, AND WILL NOT MAKE NEGATIVE OR NEUTRAL FEEDBACK. WE WILL HELP YOU FILE A CLAIM THROUGH THE US POST OFFICE AND SEND YOU ANY RECOVERED MONEY VIA PAYPAL.

 

I dont think do it yourself seperation procedure is a good idea. There is a big Leica forum at the web and there is a woman repair person who is trusted with most Leica owners. She said different glasses and their expansion rate in the heat tend to break the lenses. I am not remembering now , did I read here or there but there is special chemical baths which do the seperation without heat.
Recementing is expert business and I dont think you can do it well without a optical setup for this purpose.
Your lens is seem to worthy to pay for repair.

Umut

 

Just checking the forum title... This is the camera repair forum, isn't it? Not the "you're not clever enough to do it, so you should send it to an expert" forum...

I successfully separated an eyepiece doublet recently, and after a few false starts successfully re-cemented it using Canada balsam.

The procedure isn't particularly difficult. Sure, some patience is required, and you might need adult supervision as you'll be using acetone and xylene, but otherwise it's not so hard, and can be done in most any kitchen.