Problem soldering large tubing

I am having a problem soldering tubing. I drew 6.5mm tubing from
0.8mm sheet Argentium. It had a tight seam.

I heated it from below with the seam and hard Argentium solder on
top. Theseam keeps spreading open. I’ve annealed, redrawn the
tubing, same problem.

I have made tubing before, including with Argentium, have not had
this happen. Why is this happening? Is this metal too thin for this
size tubing?

I need tubing of these dimensions, also 8.5mm Argentium tubing,
1.2mm wall thickness or heavier (for a hinge). Can this be purchased
anywhere?

Nick… try using binding wire on the tubing before soldering.
People are still trying to figure out argentium and the way it
reacts to heat. Chris

You’ve 2 options,

  1. bind the tube with titanium wire .5mm dia.

  2. use my designed spring soldering clamp see my previous post on
    this.

Ted

Nick- When you redraw after annealing it gets work hardened again.

When I solder things that have been work hardened I anneal very
slowly with a large softish flame starting at the apex of the bend
opposite of the seam. I slowly heat and watch it open up. As I
continue to heat around the rest of it, it should relax and go back
to being closed. I rarely have a problem with it. Sometimes I just
need to hand burnish the seam a little to snug it up.

You may want to try wrapping with binding wire, anneal, remove the
binding wire and then fuse rather than solder if you can.

I love making tubing just to my specs. It’s a good skill building
exercise, you get exactly the tubing you want and it’s cheaper than
buying it too.

Have fun and make lots of jewelry.

Jo Haemer
timothywgreen.com

Thanks for the help! This was really getting me down because I
thought that heating from the opposite side of the join would expand
that side first, help close the join tighter, not make it open up.

I do not use binding wire so I never thought of that. Thanks for the
suggestion. Titanium binding wire seemed hard to locate, but I tried
Amazon and what do you know? They have it.

Thanks again.
Nick