recementing lens

[dxq.canada]

Anyone tried recementing a lens using UHU Glas ?

... and another question concerning this product ... I can't seem to find anyone in Canada/USA that sells this stuff. Is this a European only product ?

 

[Sarcophilus Harrisii]

Anyone tried recementing a lens using UHU Glas ?

... and another question concerning this product ... I can't seem to find anyone in Canada/USA that sells this stuff. Is this a European only product ?

I see no mention at all of any optical properties anywhere in the makers information page about the product (thanks for including a link to that, very helpful) so that is a red flag for me. Since there are other adhesives specially made for the process, I'm not sure why you'd want to use something that's obviously not tailored for bonding optical glass and is therefore going to yield unknown results.
Regards
Brett

 

[Steve M.]

Here's someone that used it successfully. The second link is a UK seller that has it. I have no experience personally w/ recementing optics, but would use a balsam cement if I had to. Just because it has been used for a long time I guess. All the sellers on eBait were not on the North Atlantic continent.

http://www.4photos.de/camera-diy/Delamination-Separation-Repair.html

http://www.ebay.com/itm/UHU-Glass-S...969246?hash=item33c1a244de:g:-SIAAOSwB09YDgaR

 

[RichC]

This isn't aimed so much at the OP but more as a side note...

Before anyone takes apart elements cemented with balsam in an older lens to fix minor separation, it's worth heating the compound element in an oven to soften the cement, letting gravity gently fix the fault. I've done this for a couple of lenses, including a Leica and a Nikon: 100% success with no untoward affect on optical performance (at least that I noticed).

• Support the sides of the element with heavy, heatproof items so that the top element can't reposition by sliding when the cement softens (I used large pebbles!)
• Put the element into a cold oven - you want to heat the glass slowly to prevent stress, which might crack it!
• Temperature - been awhile, but 150°C rings bell, possibly 120°C. Can't harm to start at the lower temperature and work upwards!
• I left it for an 30 minutes at max. heat, then turned the oven off and left the elements to cool for several hours.

Obviously, if things go pear shaped, it's entirely on your head! I found out how to do this through Googling. I'd suggest a thorough Google before going ahead! And don't forget that not all cements soften with heat, notably in modern lenses.

 

[Mr_Flibble]

I have 'baked' some cemented groups and laminated glass used in motorcycle goggles with success before.

But in some cases the balsam had yellowed, become opaque and cracked over the years, baking won't work to restore it.

When re-cementing elements I've had good luck with Norland Optical Adhesive.

 

[radi(c)al_cam]

This isn't aimed so much at the OP but more as a side note...

Before anyone takes apart elements cemented with balsam in an older lens to fix minor separation, it's worth heating the compound element in an oven to soften the cement, letting gravity gently fix the fault. I've done this for a couple of lenses, including a Leica and a Nikon: 100% success with no untoward affect on optical performance (at least that I noticed).

• Support the sides of the element with heavy, heatproof items so that the top element can't reposition by sliding when the cement softens (I used large pebbles!)
• Put the element into a cold oven - you want to heat the glass slowly to prevent stress, which might crack it!
• Temperature - been awhile, but rings bell, possibly 120°C. Can't harm to start at the lower temperature!
• I left it for an 30 minutes @ at max. heat, then turned the oven off and left the elements to cool for several hours.

Obviously, if things go pear shaped, it's entirely on your head! I found out how to do this through Googling. I'd suggest a thorough Google before going ahead! And don't forget that not all cements soften with heat, notably in modern lenses.

Thank you, that's actually a very very sensible idea!

 

[David Hughes]

Hi,

I once asked about restoring a Summar and was told that it would have to be boiled to 200 degrees in some liquid to get at the lenses.

Anyway, I don't think it's the sort of thing to play around with. Chances of destroying it and you are my main worry and there are people who will do it for a fee who know what they are doing.

There's too much DIY today and a lot of restorable stuff gets ruined. Then it gets sold off cheaply and people think they're so cheap they can try and repair it themselves and so it gets worst...

Regards, David

 

[johannielscom]

Hi,

I once asked about restoring a Summar and was told that it would have to be boiled to 200 degrees in some liquid to get at the lenses.

Anyway, I don't think it's the sort of thing to play around with. Chances of destroying it and you are my main worry and there are people who will do it for a fee who know what they are doing.

There's too much DIY today and a lot of restorable stuff gets ruined. Then it gets sold off cheaply and people think they're so cheap they can try and repair it themselves and so it gets worst...

Regards, David

Euhm... no.

http://tunnel13.com/blog/cleaning-e-leitz-wetzlar-summar-haze/ tells you exactly how to get to the Summar elements without boiling anything!

 

[sevo]

It probably is European only. I have used it to attach cover glass bits, eyepieces and the like. But while it is the most easily obtainable UV curing cyanacrylate cement hereabouts (off the shelf in large supermarkets and drugstores), I would not really recommend it for critical components like lenses, for the reasons mentioned by Brett - the more as dedicated lens cements are easy to get hold of in the era of internet mail order.

 

[dxq.canada]

Thanks for the info/discussion (opps forgot about product link).