I’ve been experimenting with fusing fine silver. Before I begin sharing, here's a bit of background info on the differences between fine silver, sterling silver, and Argentium silver.
Fine silver (also known as pure silver) is 99.9% silver.
In comparison, sterling silver is 92.5% silver and 7.5% mixed alloys. Usually copper is the majority of the 7.25% metal alloy added to silver to strengthen it enough for manipulation and duration. But copper oxidizes, which is why sterling silver tarnishes much more quickly than fine silver and why sterling turns black (or oxidizes) when you heat it (soldering, fusing, etc.).
Not only can fine silver be fused (bonded to itself) without the use of solder, it doesn't need to be pickled afterward ("pickling" is a process of soaking heated metal in an acidic solution to remove oxidation).
Fine silver, however, is very soft or malleable since it doesn't have any copper to strengthen it or stiffen it up. That makes it both easy and difficult to work with, depding on the project or design.
A lot of the silverwork coming out of Thailand is on fine silver because it's easier to manipulate, stamp, and texture. But you don't usually make structural pieces from it (bracelets, rings, etc) because it bends too easily.
Argentium silver is like sterling silver (and may be referred to as sterling silver) except that the added 7.5% alloy includes a substance called germanium. Since the different additive alloy isn’t all copper, Argentium doesn’t get firescale (in other words it doesn’t turn black when heated) and it tarnishes much more slowly than traditional sterling silver. It does work harden in a similar fashoin to traditional sterling silver (meaning it is not as soft as fine silver).
My set-up this week included:
- Fine Silver Wire
- Argentium Wire
- Blazer Micro Torch
- Charcoal Block
- Heat Proof Ceramic Base
- Third Arm
- Crockpot of pickle (vinegar and salt)
- Larger, unfocused torch
The things I learned are:
1) You can fuse 14 gauge fine silver with a micro-torch
2) To fuse one join, you have to heat the whole piece up (not just the join).
3) The join has to be almost imperceptible (cut flush and filed smooth)
4) If your piece is very big, it can be extremely difficult if not impossible to keep the whole piece hot enough (using a micro torch) for the join to fuse
5) Torching on a charcoal brick seems to make the process faster (the brick heats up and helps keep your piece hot)
6) Sometimes torching on a charcoal brick leaves your join mottled on the side that was against the charcoal
7) Torching with a third-arm is a good alternative, but it’s harder to keep your piece as hot as it was on the charcoal brick and it takes a lot longer to heat it up
8) It is possible to fuse with a large, non-focused torch (like a plumber's torch) but you will get different results because instead of working just a small section, the whole piece starts to go molten.
9) It’s possible to fuse pieces onto other pieces, including fine silver onto sterling silver. I attached little fine silver cut-outs to a sterling silver ring band with heat only, no solder.
10) I haven’t found a way to fuse granulation (round balls of silver) onto wire without the ball fusing to the wire in an amorphous blob. This is something I'll practice at a later date.
11) Argentium fuses in a more laid-back manner than the often frenetic quality of fine silver, making it a bit easier to get a clean, non-lumpy join
12) Argentium doesn't do well if you quench it immediately. I let it cool down before I quench or pickle it (yes, I pickle Argentium that I solder)
These photos are prior to any added patinas (I’m thinking the bead caps will particularly benefit from some LOS).
First up is my “learning bracelet”. I took 14 gauge fine silver, wrapped it several times around a 13mm dapping peg, cut the spiral into jumprings, filed both cut ends, then fused and fused and fused.
Next I wanted to see how big a circle I could fuse, so I made this 24mm one.
I continued to practice rings (some fused on charcoal brick, some with the third arm). I wanted to try light gauge too. These are 20 gauge fine silver (left and right) and 20 gauge Argentium (top). The bottom rings are more 14 gauge fine silver.
I tried adding granulation to a ring and this is the only one that didn’t blob out on me. The shadows at the bottom make it look worse than it is.
More 14 gauge fine silver.
Here's the one I was talking about earlier where I fused fine silver onto sterling (photo taken prior to cleaning).
Here are bead caps I made using sterling silver disks and fusing fine silver on top of the disks. These will look better after I add a patina.
A fused fine silver heart (25x22mm).