Total fail-soldering problems

[enigma]

Ive just spent the entire day trying to solder rope edging around bezels on a wide cuff and so far am getting nowhere :'(

I think the problem is to do with the size of the cuff ( 1.2mm thick by 40mm wide and 170mm long) and my torch ( Sievert on propane) is struggling to heat the whole piece enough.
Whats slightly odd though is that I did ( just) manage to solder the bezels on yesterday- couldn't get hard solder to flow at all but managed to do it with medium on about the 6th attempt of the day.
Any suggestions clever ones?

[Dennis]

You've really answered your question, Sarah. Cuffs often disperse the heat as fast as you can supply it and already you had trouble getting the bezels on with medium solder.

If you build a piece up bit by bit, the heat required increases with each addition. This is why where possible you try to assemble two equal parts and then join them.

In this case if you had added the decorations to the bezels first, you might just have managed'

Your recourse now is to use easy or very easy solder (if available for this metal) and possibly a bigger burner made bushy.

My favourite way to get heat there in this situation is to use two flames together: a large very bushy flame to provide the background heat, so that the piece barely glows in subdued light. Keeping this going allows you to home in with a smaller flame to do the soldering. Dennis.

[Patstone]

I had the same problem trying to solder gold squares on silver cuff, I used a big plumbers torch, but you have to be careful because its a bit of a beast and will melt if not very careful, but its worth a try.

[metalsmith]

Soldering on charcoal will lower the melting point of both solder and metals. Use of a wig or other insulating material will contain the heat. I sacrificed a jam-jar by covering it with fire-cement in order to make a small igloo like kiln. With that I managed to melt a small amount of copper with just a relatively small torch.

[enigma]

Thank you!, its reassuring to know its not just me :)
I hadn't thought that the bezels would make that much difference but I suppose given that it did only just flow before that does make sense.
Trying with easy solder now but that really doesn't want to flow either :(
If I were to buy a new torch what would be best for the job? one of the oxygen ones or?

[ps_bond]

Soldering on charcoal will lower the melting point of both solder and metals.

Um. I'm afraid I'm going to have to challenge you on that - would you like to rephrase it?
(While "engineer" is not a synonym for "pedant" there's some overlap... :) )

[Goldsmith]

Soldering on charcoal will lower the melting point of both solder and metals. Use of a wig or other insulating material will contain the heat. I sacrificed a jam-jar by covering it with fire-cement in order to make a small igloo like kiln. With that I managed to melt a small amount of copper with just a relatively small torch.

I must agree with Peter, on this statement. Perhaps you mean that soldering on heat containing materials will increase the efficiency of the torch, there is no way you could alter the melting point of solders or metals.

As to Sarah's question, I find the Sievert system torches good for general annealing of larger pieces and for melting scrap. But I like to be able to change the flame quickly when soldering certain items, as for the bangle Sarah describes I would use a large soft flame to heat the whole bangle close to solder flowing temperature, then when ready would make my flame more intense over the solder area and the solder will flow nicely. This is something learned when I was taught using a mouth blown blowpipe.
I must admit that using my ancient model Smiths little torch with propane and oxygen has been great for most soldering jobs in recent years. I used to get my oxygen from BOC, but recently found this supplier much cheaper;http://www.adamsgas.co.uk/hobby-gas-welding/hobby-gas-oxygen-gas-9l-137bar-new-bottle-detail

James

[enigma]

Thanks James

Im in France so can't get quite the same as you guys, do you think something like this would work?
Sorry its in French
http://www.mr-bricolage.fr/outillage/materiel-d-atelier-2/soudure-1/poste-bigaz-oxypower-r500.html?magasin=Gueret

I did get one to solder eventually last night with easy solder but then tried doing the next one in exactly the same way and totally failed again, gave up and went to bed at 3am…..

[Aurarius]

Im in France so can't get quite the same as you guys, do you think something like this would work?
Sorry its in French
http://www.mr-bricolage.fr/outillage/materiel-d-atelier-2/soudure-1/poste-bigaz-oxypower-r500.html?magasin=Gueret


It probably would, but before you buy it or something similar, could you try making a more heat-conserving soldering station? For instance, by surrounding the workpiece closely on three sides (you could even add a "roof" that projects part way over the work). This will reflect a lot more of the stray heat from the torch back on to the work. I do this myself on larger pieces and the difference in heating efficiency is huge. I think Dennis posted an illustration somewhere of his own arrangement.

[metalsmith]

Um. I'm afraid I'm going to have to challenge you on that - would you like to rephrase it?
(While "engineer" is not a synonym for "pedant" there's some overlap... :) )

Of course, there is 'engineering tolerance', yet to be observed :snowball:

Challenge accepted. I was trying not to be verbose. Since both solder and metals are of course... metals.

But of course what I meant was ... semi-precious metal alloys (1) intended as facilitating or expediting the joining of other metal alloys (2), usually enriched in precious metal and normally assumed to have a display, construction or supportive role in the wearing, transportation or other carrying of jewellery items ... as well as those other metal alloys in 2.

Is it the heat retention that does it? I was told the locally de-oxidised atmos had an effect, but the retention makes sense - I was always perplexed by the de-oxy.

My charcoal is usually made in-situ by starting with a short length of wood and the torch does the job, but smokes too. In this case, the burning certainly adds to the heat retention!

[enigma]

It probably would, but before you buy it or something similar, could you try making a more heat-conserving soldering station? For instance, by surrounding the workpiece closely on three sides (you could even add a "roof" that projects part way over the work). This will reflect a lot more of the stray heat from the torch back on to the work. I do this myself on larger pieces and the difference in heating efficiency is huge. I think Dennis posted an illustration somewhere of his own arrangement.


Thanks, I tried that last night and still failed.
I think if my techniques were perfect I might possibly get away with it as I did manage to eventually get one done that way but I need all the help I can get :/
Ive been out and bought one this afternoon so fingers crossed….

[enigma]

Well its very hot…..
Melted a hole in the edge of the cuff with it last night :rofl:
I don't mind too much tbh as I already had all my christmas orders posted out so less rushed now at least and can play around with this ruined one before starting again.
Its rather tricky trying to work out how much gas to oxygen you need and very different from the Sievert, Im guessing its just practise?

[Dennis]

Many years ago I inadvertently melted a large brass tap using a gas and oxygen mixture. As it was miles from any suppliers, I was in the dog house. I haven't ventured down that route since. Dennis.

[enigma]

Its hot stuff Dennis thats for sure!

[Tabby66]

Well its very hot…..
Melted a hole in the edge of the cuff with it last night :rofl:
I don't mind too much tbh as I already had all my christmas orders posted out so less rushed now at least and can play around with this ruined one before starting again.
Its rather tricky trying to work out how much gas to oxygen you need and very different from the Sievert, Im guessing its just practise?

I found it was trial and error at first with the Little torch Sarah, generally needing less gas pressure than you would think. Propane on first and add oxygen once lit.

[ps_bond]

And oxygen off first, then gas off.

[enigma]

Thanks both, still getting the hang of it….