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John Schneider
5-Oct-2009, 00:37
I have two lenses that have some separation that I'd like to recement: a Wollensak Series 1a convertible and a 19" Dagor. And now is the right time to do so, as I still have the facilities (reagent-grade chemicals, fume hood, UV lamps, programmable industrial oven, etc.). I've settled on Summers J-91 UV-cure adhesive (thanks to Kevin Crisp), and have the basic knowledge of marking the cells on the rim to maintain proper orientation, using magnets and a steel plate to align the elements by the rim, etc. But in my relative ignorance I don't know how much I don't know. Is there a published protocol etc. that I could use? E.g., should I cement and cure all three elements at once, or only do two at a time?

Tim Deming
5-Oct-2009, 10:45
Hi John,

Having done a few of these (although using Canada balsam), I'd suggest cementing in steps (2 at a time). This will make it easier to align the pieces, and you can always put the part you are cementing close to the light source, rather than having to illuminate through multiple layers of cement.

cheers

Tim

Glenn Thoreson
5-Oct-2009, 11:48
Not having any fancy equipment to work with, I do it this way: First thing upon removing the glass from it's mount, I use a little diamond bit in my Dremmel tool to cut two reference marks on the edge of the glass, about 90 degrees apart. Then it's into a jar of lacquer thinner for a few days until they slip apart.
Next comes a good cleaning, then a drop of cement, line up the reference marks, press 'em together good to spread it and get all bubbles out. Then comes a couple of minutes under the UV light bulb. Good as new, or better. When using UV cure cement, be very careful about what kind of light you work under. With the wrong light you can get a nasty surprise. It's not as easy to get it back apart, either. :D

johnschlicher
11-Oct-2009, 18:30
What kind of cement to use Glenn?

I have figure out how to get them apart--but I don't know what cement to put them back together

Thanks John

Pete Roody
11-Oct-2009, 19:39
What kind of cement to use Glenn?

I have figure out how to get them apart--but I don't know what cement to put them back together

Thanks John

Steve Grimes has some info on how to get them apart. See:

http://www.skgrimes.com/popsci/index.htm

sanking
11-Oct-2009, 19:41
I have two lenses that have some separation that I'd like to recement: a Wollensak Series 1a convertible and a 19" Dagor. And now is the right time to do so, as I still have the facilities (reagent-grade chemicals, fume hood, UV lamps, programmable industrial oven, etc.). I've settled on Summers J-91 UV-cure adhesive (thanks to Kevin Crisp), and have the basic knowledge of marking the cells on the rim to maintain proper orientation, using magnets and a steel plate to align the elements by the rim, etc. But in my relative ignorance I don't know how much I don't know. Is there a published protocol etc. that I could use? E.g., should I cement and cure all three elements at once, or only do two at a time?

I don't know if there is enough detail for you but there is a page on the S. K Grimes site about re-cementing lenses. http://www.skgrimes.com/popsci/index.htm

S.K. Grimes no longer offers this service but the article may be of some use to you.

BTW, I once had Paul Ebel re-cement a lens for me. He did a nice job for a reasonable price.

Sandy King

Glenn Thoreson
11-Oct-2009, 20:04
What kind of cement to use Glenn?

I have figure out how to get them apart--but I don't know what cement to put them back together

Thanks John

John, I use UV cure cement from Edmund Optics.
The label on the bottle says: Type J-91 Lens Bond Optical Cement. It is made by Summers Optical of Hatfield, PA. They have a web site:
www.emsdiasum.com
Phone: (215) 412-8380
Be aware that working in light with even a small amount of excess UV can cause this stuff to set up in an instant. Good stuff.

Mike1234
11-Oct-2009, 20:14
I've heard that some of the UV cements can turn yellow with age and/or repeated exposure to light. Anyone know which ones don't?

IanG
11-Oct-2009, 23:42
I've heard that some of the UV cements can turn yellow with age and/or repeated exposure to light. Anyone know which ones don't?

I think your referring to certain lenses like the early Pentax Takumar 50mm f1.4's which have glass that yellows and can be corrected by exposure to UV or bright sunlight.

The balsam cemented turns yellow with separation with some early lenses.

Ian

John Schneider
12-Oct-2009, 00:37
I don't know if there is enough detail for you but there is a page on the S. K Grimes site about re-cementing lenses. http://www.skgrimes.com/popsci/index.htm

S.K. Grimes no longer offers this service but the article may be of some use to you.

THAT'S the webpage I was looking for. I've been racking my brain to find that page, and for some reason I never thought to search the SK Grimes site.

A quick search of the MSDS shows than Canadian balsam is soluble in xylene (which I use in my research and have plenty of), so I'll try that first, rather than heat. I also have a laminar flow hood in my area I can use, so it looks like I'm all set to go. I have one cell of a Dagor that I'll practice on before I try to recement something good. Thank you to everyone for your help.

johnschlicher
12-Oct-2009, 06:02
John, I use UV cure cement from Edmund Optics.
The label on the bottle says: Type J-91 Lens Bond Optical Cement. It is made by Summers Optical of Hatfield, PA. They have a web site:
www.emsdiasum.com
Phone: (215) 412-8380
Be aware that working in light with even a small amount of excess UV can cause this stuff to set up in an instant. Good stuff.

Thanks Glen!!!, I'm going to order this

eddie
12-Oct-2009, 08:12
hey john,

you may want to look into using balsam. easier to get back apart if you need to. this is what G. Berliner uses. the UV stuff does not come apart from what i know.

that 19 inch dagor is a fairly valuable lens.....it may be prudent to get some practice before you hit that one.....or maybe even pay a pro to do it for you.

keep us posted.

eddie

Mike1234
12-Oct-2009, 08:13
I think your referring to certain lenses like the early Pentax Takumar 50mm f1.4's which have glass that yellows and can be corrected by exposure to UV or bright sunlight.

The balsam cemented turns yellow with separation with some early lenses.

Ian

Thanks, Ian, but it's the new UV cement that yellows and/or does something else odd. There are some that do and others that don't. I just cant remember which ones. This darned feeble brain of mine...

John Schneider
12-Oct-2009, 10:57
hey john,

you may want to look into using balsam. easier to get back apart if you need to. this is what G. Berliner uses. the UV stuff does not come apart from what i know.

that 19 inch dagor is a fairly valuable lens.....it may be prudent to get some practice before you hit that one.....or maybe even pay a pro to do it for you.

Hi Eddie,

Point well taken. I haven't given them a call, but based on their website, Summers UV-cure cements are resistant to most chemicals, including the xylene/MEK/acetone etc. that typically allow removal of elements cemented by balsam. However concentrated acids (6+M, yikes) do soften the UV cement (but no idea on how vintage glass would respond to 12M HNO3).

Do you know a source for optical-grade Canadian balsam? That might be the better route to go.

Glenn Thoreson
12-Oct-2009, 11:16
Edmund Optics should have Canada Balsam, too.

Peter K
12-Oct-2009, 11:21
Do you know a source for optical-grade Canadian balsam? That might be the better route to go.
Eukitt (http://www.emsdiasum.com/microscopy/technical/datasheet/15320.aspx) works also with lenses. And can easily removed without concentrated acids but with xylene.

Peter

IanG
12-Oct-2009, 23:14
Thanks, Ian, but it's the new UV cement that yellows and/or does something else odd. There are some that do and others that don't. I just cant remember which ones. This darned feeble brain of mine...

Only problem I know of with the new cements was the separation issue with the early Rodenstock Sironar's, Grandagon's etc that used them. But then you have one of those :D

Ian

Mike1234
13-Oct-2009, 07:09
Only problem I know of with the new cements was the separation issue with the early Rodenstock Sironar's, Grandagon's etc that used them. But then you have one of those :D

Ian

Yes I do. Wanna re-cement it for me? :)

Robert Hughes
13-Oct-2009, 08:23
Microscopy supply houses also stock Canadian Balsam - that's where I got mine. They use it for permanent slide mounts.

Phil
13-Oct-2009, 09:32
Surplus Shed has it in stock, too:

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

imagedowser
2-Nov-2009, 17:57
Ordered a qt/lb from surplusshed last week, came today. I use resins for varnish making and this looks very nice.