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Spectacles and solder.

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Robin Graham02/08/2020 23:09:58
771 forum posts
193 photos

My specs broke a few weeks ago:

img_2368.jpg

Because of lockdown I couldn't get an immediate appointment with with my optician, so I soft soldered the join. For reasons too tedious to explain, when I did get to see him he advised me to wait six months before buying new specs and live with the bodged ones until then. "You're obviously very good at repairing things" he said, but I'm not - the soldered join has (predictably) failed.

To get to the point - I'm now thinking about silver soldering, but I seem to remember reading somewhere that it's impossible to silver solder a join which has previously been soft soldered. Is this true?

Robin

pgk pgk02/08/2020 23:27:54
2015 forum posts
290 photos

Also remember something about leaded materials not taking to silver solder. Also the additional heat involved may compromise those nose plastics unless they can be easily removed/replaced. However this is more a case of practicality than restoration as original so I'd suggest resoldering the failed joint and then reinforcing with a new piece along the top of the frames. In fact my own specs have such double bars.

pgk

Mike Poole02/08/2020 23:38:38
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Moderator
2842 forum posts
67 photos

I bought a pair of titanium framed glasses but they broke rather as though they had work hardened, the first break was in the centre of the bridge which I sleeved and crimped as a temporary repair which served for a few months then an arm snapped. Neither break occurred when the specs were being stressed and so far the replacement frame is ok.

Mike

Old School03/08/2020 06:13:47
365 forum posts
32 photos

You need to get them welded, some people who do jewellery welding may be able to help.

Gary Wooding03/08/2020 07:14:10
776 forum posts
196 photos
Posted by Robin Graham on 02/08/2020 23:09:58:

To get to the point - I'm now thinking about silver soldering, but I seem to remember reading somewhere that it's impossible to silver solder a join which has previously been soft soldered. Is this true?

Robin

I don't know about lead free soft solder, but it's certainly true about leaded solder. When trying to silver solder precious metal that has been lead soldered, when the lead melts at the elevated temperature required for silver solder, it acts rather like mercury and precious metal - it creates an amalgam (or something similar) which eats into the precious metal. The attempted 'joint' just disintegrates.

I've successfully welded spectacles with my PUK welder.

Keith Hale04/08/2020 08:08:30
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282 forum posts

The problems associated with lead and silver solder has nothing to do with the formation of an "amalgam" type compound that eats into the silver solder.

The problems are that lead has the tendency to work against the fundamental principle of successful silver soldering (capillary flow) and alloy selection.

Lead and silver solder is a recipe for disaster. Simples!

Regards

Keith

Lee Rogers04/08/2020 08:33:58
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91 forum posts

First set the specs up in position with plasticine or whatever and bond the joint with a suitable cyano, loctite , superglue type adhesive. Once it has set make a splint from hard wire (paper clip or safety pin ) and bond that in place with the superglue. Once set you can then apply a thin coat of 2 part epoxy over the entire repair allow to set and repeat untill a layer of epoxy has built up over the entire repair. Superglue is useless on it's own and the area of the break is too small to repair without the splint to spread the load. My £££ varifocal ultralights are still going after 3 years.

I keep thinking that it would be a fun project to make some frames from scratch but SWMBO says I'm not allowed .

Robert Atkinson 204/08/2020 08:44:36
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879 forum posts
17 photos

The UV curing glues based on dental cement work well for this, They can be built up and mouled into a thick fully cured layer. In your case solder it again to locate and hold and then build up the glue to add support.

Do it neatly across the bridge and both sides and it won't look so much like a repair.

Robert G8RPI

Lee Rogers04/08/2020 09:26:47
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91 forum posts
Posted by Robert Atkinson 2 on 04/08/2020 08:44:36:

The UV curing glues based on dental cement work well for this, They can be built up and mouled into a thick fully cured layer. In your case solder it again to locate and hold and then build up the glue to add support.

Do it neatly across the bridge and both sides and it won't look so much like a repair.

Robert G8RPI

I've seen the miracle claiming advertisments for the UV glue . So it is good stuff? Where do you buy from?

john fletcher 104/08/2020 09:39:59
651 forum posts

If you have your prescription details, get another pair from one of the advertisers on the net. The owner of a company about 20 miles from us who made all type of spectacle frames, told me NON cost more than £1.50 and he went out of business when under cut be an Italian company. John

Danny M2Z04/08/2020 09:43:48
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914 forum posts
292 photos
Posted by Lee Rogers on 04/08/2020 09:26:47:
Posted by Robert Atkinson 2 on 04/08/2020 08:44:36:

The UV curing glues based on dental cement work well for this, They can be built up and mouled into a thick fully cured layer. In your case solder it again to locate and hold and then build up the glue to add support.

Do it neatly across the bridge and both sides and it won't look so much like a repair.

Robert G8RPI

I've seen the miracle claiming advertisments for the UV glue . So it is good stuff? Where do you buy from?

Used by fishing fly tyers so search for something like this (which I use in Australia) Loon UV Cure Epoxy

Gary Wooding04/08/2020 14:44:20
776 forum posts
196 photos
Posted by CuP Alloys 1 on 04/08/2020 08:08:30:

The problems associated with lead and silver solder has nothing to do with the formation of an "amalgam" type compound that eats into the silver solder.

The problems are that lead has the tendency to work against the fundamental principle of successful silver soldering (capillary flow) and alloy selection.

Lead and silver solder is a recipe for disaster. Simples!

Regards

Keith

I agree that lead and silver solder is a no-no, but I really have had lead form an amalgam type substance when I didn't realize that I hadn't removed every scrap of lead from a previous repair to a gold ring.

Mike E.04/08/2020 15:15:41
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209 forum posts
31 photos

Your optician doesn't seem to be worth his salt if he can't order you a replacement frame from a catalogue to install your lens in.

Edited By Mike E. on 04/08/2020 15:16:18

Edited By Mike E. on 04/08/2020 15:18:51

Neil Wyatt04/08/2020 16:41:09
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Moderator
18404 forum posts
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78 articles

I kept a pair going for years with a silver soldered join, I think I re-did it twice.

It was a silly expensive titanium frame and I used a brass tube over the two ends of the broken part.

I took the lenses and nosepieces off to do the deed.

Strange I never had a cheap steel one break like that...

Neil

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