Uv glue for lens repair

[monkeymon]

http://www.ebay.com/itm/UV-Glue-LOCA...-/111116833201

Is this kind of UV glue suitable for lens recementing? I have one lens i would like to try to repair, and would like to find some cheap UV glue that gets the job done.

[Kevin Crisp]

It might work. If the lens has any potential, I'd get the real McCoy:

http://www.optical-cement.com/cement...l#anchor669157

[imagedowser]

Monkeymon,
Reversibility may be your best friend. I did my first recementing 3x before I was satisfied with the work. Canadian Balsam is much more forgiving than UV... I've done over ten lenses and still haven't found a need to use UV cement. I understand UV is a pita to get apart if you need to.... besides this is supposed to be fun, so introducing any unnecessary level of stress is counter to my good time. Mike sells Canadian Balsam at Artcraft Chemicals.

[Steven Tribe]

Having done more recementing than I can remember (30 plus?), my advice is to use Canada Balsam - even where the original cement is synthetic.

-Optical cement has a short shelf lifetime. Months rather than years.
- Canada Balsam in sealed, cool containers, keeps for decades.
- Optical cement will not be easy to remove if you make a "scrap" join.
- Mistakes with Balsam can be easily rectified with solvent.
- Balsam lasts for over 100 years and give warning of separation.
- Synthetics last ?? years and my experience is that separation occurs without warning (twice in transport in my experience).
- Balsam smells nice and is a lot cheaper, and can be used for other optical mounting activities.

[monkeymon]

The lens i'm trying to recement is Angulon 90/6.8 where the elements are cemented in the metal frame... i don't feel comfortable heating the whole thing... and the elemen i'm gluing is so freaking small, that i need something that cures fast when i get in the right position.

Actually one optician commented that i can use just regular cheap hardware store UV glass glue, so this is what i'm probably going to get... he said that the chemical composition is the same in these types of glues.

[Kevin Crisp]

If you just tack it in place (45 seconds or minute or so of UV from a CF bulb) it isn't that hard to get it apart if you check it out and decide you are off center. Unless this cheap cement cures in the sunlight range, in which case it takes sunlight or a sun lamp.

I have never used balsam, but the UV cure cement from Summers has worked well for me.

It is hard to get right the first time. Or the second, or third. But once you get the hang of it this isn't that hard. Cleanliness is everything before applying cement. Use really clean fresh acetone to get the lenses surfaces clean.

[Jody_S]

Dunk the whole assembly in paint stripper, it will come apart in a day or two. The synthetic cements have successfully held together millions of lenses from every current manufacturer for more than 50 years; I don't really think longevity is an issue if you get the right cement. BTW, paint stripper has separated the lenses I've screwed up with my own version of UV-cure (clear-coat nail polish, UV-cured, or Krazy glue).

[Kevin Crisp]

MEK will separate the UV cure cements if you soak for a day or two. If fully cured it might take a week.

[John Koehrer]

Paint stripper is quicker. Than MEK.

[Randy]

Got an old R. R. a couple years ago, had bad separation. Soaked the group in acetone for about a week to dissolve the balsam. Didn't want to mess with glue so I put a drop of vegetable oil in the center and it worked like a charm until I sold the lens (full disclosure of course) a year or so later.