Fusing Argentium to sterling, how to minimize fire scale?

I’ve never soldered nor fused. I have been working with Argentium and sterling wire for cuff bracelets and other things. I wanted to learn mounting gems and cabochons so I planned to see if I could mount one on rectangular silver wire (think 5-8mm wide rectangular wire cuff bracelet with a stone on top).

There isn’t rectangular Argentium wire yet (or at least from Rio) so I needed to use sterling. But Argentium bezel cups are available. I’ve read that Argentium readily fused to other metals and alloys like sterling so I decided to try to fuse the Argentium bezel cup to the sterling wire.

I used Rio’s My-T-Flux (good to 1700), although right off the bat, silver obviously isn’t absorbent and the flux seemed to just pool and bead on the silver. Is that how it is supposed to be? It does not seem to give a “nice thick coating”. I both dipped it and used a q-tip to try to spread the flux around. What is the proper technique for flux?

I used a good butane torch. The fusing took longer than videos I’ve seen. I think I did not do a good job of concentrating the heat on the tiny 5mm bezel cup and ended up heating the entire piece too much. I fire-scaled the living hell out of the wire, it was even black underneath. I managed to sand it all out, but had to remove a lot of material as the fire scale went MUCH deeper than I would have thought.

It sounds like there is no way to 100% prevent fire scale on sterling but that it can be minimized. Any advice on that end, in particular when heating to fusing temperatures? I know my torching technique has to improve, what else I can do?

Hi there,

from what you wrote, i have a few thoughts:

  1. metal must be clean in order for flux to coat fully. to test for cleanliness, run water over metal…it should “sheet” and fully cover piece…if it beads up then metal is not clean enough…
    (i use dawn dishsoap and a soft toothbrush, or nail brush, and then water and pumice powder (made into a little bit of paste)

  2. try searching archives for Prips flux/ Pripps flux recipe… it is a barrier flux to protect, not a (solder) flow flux… it is formulated to achieve great results…stays active longer and at higher temps…

  3. for your wire cuff bracelet, a butane torch may “just” not provide enough heat…especially if you are moving flame over a large area…there are several sizes on the market…you nay need to add the slightly larger torch to your arsenal of tools.

  4. i have personally found that it is not neccessary to heat the whole piece up to flow temp…try concentrating the heat on the the thicker bracelet wire near and under the bezel cup…wire will transfer hear to bezel cup…when both areas are at temp, the solder will flow, or metal will fuse
    julie

Hi Julie,

Thanks for the insight! I wonder if there is a pre-made barrier flux product out there vs having to make it? (I’m lazy). I’ve checked some videos of people making fluxes and they seem to make them pasty. Is a barrier flux basically a thicker flux? Any commercial brand you recommend?

Hi,

Pripps/ Prips is the best in my experience, 3 powdered ingredients (borax, boric acid, TSP) plus boiling water (make in a jar to store, use a spray bottle to apply, flush sprayer at end of day). cheaper than proprietary brands.

heat metal a little, spritz on, should immediately dry to a white powder coating.

search archives

boric acid/ denatured alcohol as a dip/ brush on also works but does not stay active as long, and at lower temp.

trick is also to to get in and out hot, as quickly as possible, reducing amount of time heated piece is exposed to oxygen

julie

Hi again,

forgot to say:

flow flux like borax cone, handiflux, dandix, griffiths, etc is needed for solder flow

barrier flux like Boric acid and denat alcohol, Pripps/Prips, cupronil, firescoff, etc help protect metal from oxidizing

( all kinds of detailed technical info in archives)

firescale surface oxide formation
firestain below surface oxide formation

sorry no comments on fusing, as i dont have experience there…

julie

Prip flux is really easy to make and use. Rather than looking for ready made, and spending lots of hard earned money, just make a batch. Ganoksin archives has a recipe.

I ordered a bottle of firescoff for now. That will give me a baseline for comparison when I try making a batch of prip

awesome! hope you like it!

julie