Argentium silver fusing and soldering problem

[Molek]

Hello
Hope someone will have an insight into what is happening with my project. I am making an Argentium silver bangle that will feature a Tahitian pearl in the middle. The design is to have a sort of thick silver halo around the pearl (bead) which will be fixed on the halo with a wire. From the halo two fairly thick, 4mm wide, oval silver wires (more like bars) form an open cuff.
All was good for a while - I made the halo, soldered it perfectly with extra hard solder (Argentium) finished it beautifully, drilled the wholes and then proceeded to add the two wires, one at a time, on each side. And this is when everything went haywire.

The solder wouldn't flow, no matter how much I heated the piece, and when it seemed like it did flow the joint was so weak that it came off with no effort. I tried several times to no avail, and to the point where the halo got a few cracks and ended misshapen.
As a side note, I worked with the alloy a few times but on a much smaller scale and never had a problem. Duh, I even sang praises to anyone willing to listen about how amazing it is to work with Argentium (I usually work in gold, and dislike working with silver).

After I did read up on working with Argentium, I corrected my mistakes - laid the piece flat to support the fragile hot Argentium, obsessively cleaned and aligned the parts, and made sure I wait for the Argentium to air-cool before quenching. At first, I fused instead of soldered, which only worked on the remade halo and one side of the bangle. After trying to fuse the remaining side three times I decided to use solder. This time it worked for the remaining side BUT the fused side (which until this point was super strong) AND the fused joint of the halo decided to come apart. When I tried to fix that by soldering them a new crack appeared and the soldered bit came off.
I added support (only after it was clear that without it, the joints are not 'close' enough) on each side of the bars/wire part to make sure the joints are tight, but there was not much pressure to make sure the halo isn't squashed.

I am at a loss as to what to do now and thinking of switching to normal sterling as I'm 100% sure I wouldn't have this many problems with it...

I do not understand why the fused joints came apart - I thought the fusing is permanent and won't be as fragile as soldered joints??

Any suggestions will be welcome :'(

Exhausted and clueless
Monika

[china]

My observations - joints were not properly fused, you overheated the joints causing the joints to fail, fusing that type of structure is bound to fail if you heat it up to fusing temperature all the joints will be heated. My opinion is it would be better to use solder, Extra Hard/Hard Solder-highest melting point, then Medium Solder-medium melting point will not melt the Hard Solder joints, followed by Easy Solder-lowest melting point will not not melt the previous two grades plus with all due respect when you use solder you are using flux.

[Molek]

My observations - joints were not properly fused, you overheated the joints causing the joints to fail, fusing that type of structure is bound to fail if you heat it up to fusing temperature all the joints will be heated. My opinion is it would be better to use solder, Extra Hard/Hard Solder-highest melting point, then Medium Solder-medium melting point will not melt the Hard Solder joints, followed by Easy Solder-lowest melting point will not not melt the previous two grades plus with all due respect when you use solder you are using flux.

Hi China

Thanks for your response, flux was used when fusing and soldering. What baffles me is that fusing supposedly creates a seamless/solid structure, unlike soldering - unless that's not the case at all?

Also my understanding of Argentium, so far it worked with smaller projects, is that you are more flexible with using the same solder grade as the alloy behaves more like gold than silver in this respect?

[CJ57]

I’ve never used argentium but done properly a solder joint should be invisible if the edges are good, I use it on cuffs

[china]

Yes it does produce a seamless structure if you get it perfect, fusing is a bit of an art and takes some practice to get right, never heard of using only one grade of Solder with Argentium if that were the case why would they make 4 different grades of solder.
99% of my Silver work is Argentium the joints on any precious metal should be very tight and clean before you solder, the better the joint the better the end result will be, same goes for fusing.

[Molek]

Yes it does produce a seamless structure if you get it perfect, fusing is a bit of an art and takes some practice to get right, never heard of using only one grade of Solder with Argentium if that were the case why would they make 4 different grades of solder.
99% of my Silver work is Argentium the joints on any precious metal should be very tight and clean before you solder, the better the joint the better the end result will be, same goes for fusing.


It's not that you don't need different grades of solder - there's definitely a need for them. What I meant was that argentium, like gold, requires heating the seam only, rather than the entire piece which means you can successfully use one grade of solder without having to worry that you will ruin an entire piece.

Anyway, something is fishy about my silver because it is not taking the solder at all...

[china]

I have been using Argentium for 10 years without any issues to speak of I do not like the Argentium flux, although many people seem to be fine with it.
Where did you buy you Silver or your Solder, from a reputable supplier ? purchasing from Ebay etc. is like a lucky dip. Have you tried just soldering a couple of pieces of scrap to prove the point.

[Molek]

I have been using Argentium for 10 years without any issues to speak of I do not like the Argentium flux, although many people seem to be fine with it.
Where did you buy you Silver or your Solder, from a reputable supplier ? purchasing from Ebay etc. is like a lucky dip. Have you tried just soldering a couple of pieces of scrap to prove the point.

I bought it from cookson here in the UK. I will experiment with some scrap - that's a good idea.
Can I ask if you make large chunky pieces? Have you ever had any problem with misshaping when heating your pieces? how do you support them?

Thanks

[Molek]

I also use auroflux, which I use for all my soldering, what solder do you use?

[china]

I use traditional borax based Flux, I have used Auroflux in the past and with Gold although I don't see any advantage. I did have problems in my early days of Argentium if is collapsing you have most likely overheated it, also always let Argentium cool for a Bit before you pick it up, re support I use anything that works, binding wire, titanium clamps. (see Link) broken fire bricks self lock tweezers etc.
https://www.cooksongold.com/forum/showthread.php?t=10951&highlight=titanium+clamps

[Molek]

Thanks for the info, I will experiment some more.

[alastairduncan]

This may not help you with your soldering problems but it may be useful for you in the future.

Cookson's are supplying argentium 940. This version of argentium is more robust at high temperatures.

https://www.argentiumsilver.com/post/new-argentium-940-silver-metallurgical-improvement

[Molek]

So just a quick update - I resolved my issue by soldering twice - with the same grade of solder (medium) instead of extra hard- on both sides.
I watched Nancy Hamilton video about fusing argentium, in which she turns the piece (after letting it cool enough so it doesn't fall apart) and heats the portion of the pieces that was previously resting on the soldering block. This gave me the idea that only the top side of my bracelet gets sufficient heat to take solder. The bottom was usually too cool and therefore had not appropriately adhered resulting in a weakened joint. So I flipped my piece, soldered again and it's as sturdy as it should!!
Hurrah!

[Molek]

That's really interesting, Thank you! I had to order the Argentium from Birmingham branch and asked for 940, but somehow they send the 935 instead, which might explain my problems!