It was a real pain. I pickled them again, brushed them (no dishwashing liquid this time), cleaned them with 96% alcohol, washed them in water, dried them with fresh paper towel, fluxed them twice, used that copper solder that worked yesterday....
it took ages and a half, if not longer, in the end the solder finally melted. I definetely had the feeling it did not want to but had no choice but to give in.
I hope the other 31 bangles are done faster or I will be finished by the time I get a senior citizen pass
Btw is it correct that a blue flame is really hot, a red flame not so much ?.....what about when the flame itself is blue, the spot where it hits the copper red and a bit further away green? Got a whole rainbow here.....
Last Edit: Feb 17, 2014 11:26:00 GMT -6 by galadryl
That might be one of the problems. Sounds like you're not heating up the entire bangle. Are you only heating up the area where the solder is? What can happen is that the solder will melt but it wont flow because the copper is not hot enough. Copper tends to absorb heat throughout the entire piece.
I don't know what torch you're using but if it's propane/oxygen then there should be a slight hiss. The cone of blue, should be about 1/2"/12mm long and the flame itself about 30-35mm.
Yes the blue cone is the hottest part of the flame.
I don't know anybody who has got one. But that is ok, I would be too scared to use it anyway.
A few years back I did a gold-smithing course and I was really scared to even get the torch going, we had to do it with a cigarette lighter and the room was always smelly of gas (at least to me), it took me about 5 years to overcome that fear and get a proper torch (before only micro and max flame) and operate it on my own. Just having it for a few months now. I have got a lot of respect for fire and gas. Maybe in another 5 years
Last Edit: Feb 19, 2014 4:30:53 GMT -6 by galadryl
I had another try. I have got two "heads" for my torch, a small one and a larger one. I was told the small one is for soldering and the big one for annealing.
Ok, I used the big one for soldering one of the bangles. It did work but the solder and the surrounding reticulated a bit. That is at least what it looks like. I guess I used too much heat but at least it worked. Try to do better next time
If your copper has an anti tarnish treatment, the solder won't flow. Ask me how I know this...way to many wasted hours and hair pulling! I was using recycled 10 ga copper ( the DBF brings home bits used in electrical work) and OMG does it have an anti tarnish on some of it. Once I broke out the steel wool, pickled it, and neutralized the pickle.... the solder flowed, the heavens opened, and all was right in my little world...til the next opps momemt anyways. LOL
ETA: Love the bees wax and wintergreen oil for lubricating my saw. I use bur-life on my drill bits though.
Ok, the burr life, unless it was really really all over everything was not the problem. The most likely culprit was you weren't getting the piece hit enough fast enough or not at all. Copper also has a tendency to absorb certain grease like oils that collect in its pours (yes it has pours) if the flux doesn't go to solid glass like state fast enough (and copper heats slower than silver or gold ) the oil comes out and becomes a flow blocker. Copper also doesn't conduct as well, has a much higher melting point and it's harder to gear the entire piece and keep the entire piece hot enough to make it work. So, my advice, is clean it ultra ultra well make sure the joint seam is clean, flush, and very tight, and use paste solder (ss70 medium fluxes paste solder. Cover every surface involved in the joint, and heat effectively.