Soldering copper onto silver

[Dennis]

That's solved that then, but at the back of my mind the question remains: what was the problem that prompted this query? If we knew, there might be other approaches you hadn't thought of. Dennis.

[susieq]

Thanks James - I seem to have ordered two thicknesses of stainless steel and thought the cross-brace was cut out of thicker. I will abandon this and revert to the thinner, which I did not try.

Dennis - its the same old same old of from me of wonky soldering - I'm trying to make a russian bangle set out of silver wire but the darn stuff keeps moving just before the solder flows. I start off with nice tight joints, just a little bit of spring to keep the wire together, heat gently opposite the join to start with and then gradually move around. Just as the flux clears and the solder looks as if it might consider flowing, the join opens up and the wire moves slightly. Hence, I thought I'd give the clamps a go. The wire I'm using is 2mm thick, although I also have 2.5mm and 3mm, as I thought I would mix in different widths for a bit more interest.

I don't yet have a torch at home (still looking for the "one fits all", which of course, does not exist) so I only get a couple of hours a week at evening class to try and solder and its driving me nuts. Yesterday I tried soldering 3mm round wire, and apart from looking like the whole thing was going to melt just before the solder ran, the soldering joint although not too bad, is still not good enough for my liking.

Anyway, my trial and error at working out the size for the bangles is working out as more "error" so I have cut the joins and taken 1cm out of each. Although I didn't have time to solder them yesterday, they do look like they may hold together better, so am keeping my fingers crossed for next week.

Susie

[Dennis]

Yes, I have been making bangles lately and hope to show the results next week. It is surprising just how much heat, evenly spread, you need for these quite thin wires. What you are trying to do is to bring the whole bangle up to temperature, not just the join. I got round this by building up a kiln with bricks to retain the heat. You might also have better results using easy solder which flows at a lower temperature.

It looks as if James’ cross brace will do the trick for holding the ends together, although I ended up tying the wire to a perforated brick with binding wire instead.

For home use you can get away with a minitorch for small items and links, plus a DIY plumbing torch which uses canisters of propane butane mix from ironmongers or DIY stores. Either Campingas or Go System will do, but if you can afford it get a self-igniting one. The size of the canister only affects the length of time it will stay alight, and which make you choose depends on local availability. For extra heat you can sometimes use them together like toting two guns.

You also need a hearth such as a stout roasting tin and nothing flammable behind it. Dennis

[susieq]

Thanks Dennis

I have one of the self igniting plumbing torches but have only used it for annealing - the flame doesn't seem to adjust sufficiently for soldering jobs. In the instructions it says there is a finer nozzle available, but I've yet to track one down.

I've only ever used hard solder - my stubborness tells me that I need to master it, and as my joints are less than perfect easy solder joints will show more and annoy me.

On a positive note, at least soldering and resoldering will give me more practice - and I have platinol to hide the firescale if necessary!

If I summon up the courage I'll post a photograph of the copper bangle I was trying to solder yesterday - I sweat soldered part of it and tried to use a pair of reverse action tweezers to hold it for the second part of the soldering. Needless to say it hasn't soldered, but I have a rather bent and singed pair of tweezers that I need to replace!

Susie

[Dennis]

I forgot to mention, that for this purpose, a few pallions of strip solder work best. In reply to your comments:

1.Once alight, it is possible to reduce the flame to about three quarters of its full size by turning down the gas, so reducing the heat.
2.The hottest part of a flame is close to the tip of the blue cone, so by using that part of the flame furthest from this you can reduce the working temperature further.
3.Lastly by moving the flame around continuously, you will not over heat any part of your work. This is best monitored in subdued lighting.

As for the difference in colour between hard and easy solder for these small joints, you will be hard pushed to tell the difference.

I did originally have a pencil attachment for my torch, but never found it much use and soon gave it up.
Dennis.

[Patstone]

I am glad someone else has problems soldering wire bangles with the plumber type gas cylinder torch. I already had one from before that I bought to solder a pipe once, and thought "ideal, I wont have to buy one", but found the same as you the flame is ideal for annealling and heating big items quickly but useless for soldering, and I couldnt find a smaller nozzle either. I bought a small cooks torch, which I still find very good but needs refilling often and the heat is very intense and sometimes too much, and at the same time I bought a torch similar to the Sievert one, which is marvellous. The only pain is that it isnt self igniting, and uses a big bottle which isnt ideal for spare bedroom soldering - but saying that I use it out of preference, but it was expensive to buy to start with. The gas bottle is a bit bulky tho, (but mine has lasted about a year), standing about a foot across and a foot high, but under the bench its fine and out of the way.

[Patstone]

Hi Dennis, I like the idea of the roasting tin, it would be ideal in my situation, no more burnt carpets where balls run off the desk and make nasty black marks, and the stink of burning wool - yuk. Pat

[Patstone]

Hi James, I used some stainless steel staples that I had left over from re-upholstering a stool, they worked well but a bit small, so I too will be copying your idea of making your own. As you probably know I am blind in one eye and find judging distance a problem so I set things up nicely for soldering, but you can bet your life that by the time I go to solder it I have knocked it off, and have to start again, thanks once again for your good ideas and the help you have all given me since I started.

[mizgeorge]

I don't know if it helps anybody, but my favourite tool for holding bangles in place for soldering is a pack of 'T' pins (as used by quilters and picture framers). I place these around the outside of the whole bangle, either on a honeycomb block or directly into a charcoal brick, and they hold it perfectly in place, stop any expansion at the joint, and don't have the heat sink effect of using heavier clamps. I generally opt for two hand torches, or one propane and a second hand torch to heat from both directions rather than going in with a bigger flame, and risking overheating.

[Patstone]

Hi George, I have heard you speak of these T pins before, I think they are a good idea, I must have a look for some next time I go into town. Normally by the time I get back from walking dogs I dont have the energy to go around town as well. Not quite sure where to look for them either, any ideas would be welcome.