Soldering 4mm diam. silver bangle-Help!

[silvanian]

Hi
I'm new to soldering and trying, not very successfully, to learn out of books. I have a Sievert pro86 soldering kit with all the usual nozzles but whatever I try I can't get the above bangle up to soldering temperature. 2bar and propane. The bangle is held in a wood fitting (ie not a heat sink) and the seam is in 'free air' ie it is held vertically rather than laying horizontal. I don't know whether I'm trying to heat too much mass for that type of soldering system or if my technique is wrong. I am heating the seam at the tip of the blue innercone of the flame- which I believe is correct. Could the solution be to lay the work horizontally- does this generate much more heat by reflection?
Thanks to anyone who can help.

[MuranoSilver]

Could you put a picture in your picture gallery (available from your profile)
Not sure what you're trying to get to solder...
Nic xx

[mizgeorge]

I think you might get better results working flat, using a charcoal block or soldering mat to get more heat reflected back onto the piece. Raise the area being joined very slightly with a piece of copper or iron wire and start by heating the whole piece before concentrating on the areas either side of the join. You should be able to heat this size of wire enough with a propane only torch. Alternatively, use a tripod and wire mesh to allow you to heat from above and below more efficiently. Using any holding mechanism will stop the heat from flowing freely throughout the piece - I suspect I'd just set fire to a wooden fitting!

[silvanian]

Hi
Thanks for your feedback. I'm trying to solder the seam of a 62mm diameter bangle made of solid 4mm diameter silver round wire. I'll try laying it flat as suggested on charcoal blocks and see if I can concentrate the heat. I guess I wanted some pointer that the torch is Ok - I just need to work on my technique!
Thanks again

[ps_bond]

What diameter nozzle are you using on your Sievert? The 17mm needle flame might be pushing it a bit for the heat required even with reflection.

[silvanian]

Hi
I have tried 5 different nozzles: 1x the small needlepoint(11mm), 3x what sievert call 'pinpoint' ranging from .2 to 1.2 kw (17mm) and some monster 28mm nozzle probably of better use to a paint stripper. I did contact Sievert and they weren't able to throw much light on the problem - just said propane burns at 1900c and so it should be ok , but obviously it also depends on the mass you are trying to heat.

[ps_bond]

11mm? I can see some uses for that on mine... Smallest I've got is the 17; my general heavier one is a 22mm. Could you describe how you're actually heating the thing? You've mentioned the blue cone; the hottest part of the flame is indeed just ahead of that - are you progressively getting the rest of the bangle up to a reasonable temperature to avoid the metal conducting all the available heat away from the joint? Laying it flat on the firebrick will help - far more of the heat will be retained & reflected back to the wire that way.

Have you tried doing this with thinner wire successfully?

There are a few soldering videos on Youtube that might be of use - I can't see one that really matches the weight you're trying to do, but this set is pretty good:
YouTube - Silver Soldering by Andrew Berry - Jewellery Repair Bench Tips Techniques Part 1
YouTube - Silver Soldering by Andrew Berry - Jewellery Repair Bench Tips Techniques Part 2
YouTube - Silver Soldering by Andrew Berry - Jewellery Repair Bench Tips Techniques Part 3
YouTube - Silver Soldering by Andrew Berry - Final Part - Jewellery Repair Bench Tips Techniques

[Petal]

Those Youtube Vids are well worth watching. I had a look at a few yesterday, prior to doing my first soldering joints and learnt loads, along with the peeps on here offering excellent advice, of course! Let us know how you get on.

[ps_bond]

Just noticed he's got another one on Sievert torches specifically.

[silvanian]

Thanks to everyone for their help. I've tried heating the whole bangle to stop heat being drawn from the seam - it's a bit like chasing your tail but I will persevere , watch those videos, build me a mini furnace and lay it flat. I'll let you know how it goes.