Spectacles and solder.

My specs broke a few weeks ago:

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

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

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

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

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.

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

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 .

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

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

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

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.

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

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