Rob MacLennan

... like embedding it in open-hang 4-in-1, with tension on it.

Which is why the location of the electrodes on the TRL welder is particularly good. A roughly 45 degree angle redirects half the force into pinching the ring's gap during welding.

I typically don't hold for more than a second or two, but Lorenzo would be the expert.

My only experience has been hosing off a finished piece with a soap dispensing car cleaning nozzle and the inside was soaking wet. Then again rain doesn't hit at 90 degrees, under pressure.

If they're already reasonably close, then you're minimizing the heavily heated area. I was afraid that you might have them quite far apart.

Are your electrodes placed fairly close together, as in the TRL welder?

There's likely some form of adjustment hidden in its carcass. Perhaps both duration and strength of pulse. If so, then the 'conversion' would be easy. *EDIT* In my searches I've turned up more than a few Chinese dental welders that have very similar cases to the old TRL welder.

I've wondered if something like this might be adaptable to ring welding. https://www.harborfreight.com/120-volt-spot-welder-61205.html

I'd say your assumption of high current, low voltage is correct. I don't see any arcing. Thanks for the safety recommendations. I'm usually using darkened safety glasses, if not an actual mask.

Couldn't tell you the output current, because it doesn't have a rating for it that I can find. I can tell you that it's rated at 2000W and two quick pulses will blow a 16 gauge mild steel ring like a fuse. It can be tuned with a digital setting over 30 steps from barely a tingle, to melt into slag. This is my video of it in use.

The most common method for ring welding is resistance welding; essentially with a purpose made spot welder. The RingLord used to sell resistance welders (I got one of the last three before they were discontinued), bu some people have built their own using coils from microwave ovens. It can be plenty strong if it's a weld right through the material, but this video shows little more than a tack weld.

There are a few possibilities, depending upon what you mean by "big." You could taper down to a single "big" ring on each side and then only use 1 lobster claw, though this would mean the bracelet doesn't have a uniform width. If your rings are sized appropriately you could use magnetic "tube clasps", though these tend to be for smaller rings rather than beefy ones. If the rings are an appropriate size you could use EPDM rubber rings in one of the sizes, thereby making a stretchy bracelet that could be solid, without using a closure.

And it's back up now.

Unfortunately there's nothing that can be done to fix external links. It looks like their forum is down and that's where the stuff is stored.

I can't speak for their composition but I welded rather a lot of TRL's 5/16". 16 gauge stainless rings for the shirt in my user pic, and I'm still here.