Would the zinc in Sterlium Plus mean that it’s unsuitable for
enamelling (zinc causes pitting in the glass) Or would depletion
gilding solve that? For that matter, does Argentium support enamel,
or is the germanium a problem?
Janet
Janet-I like Stuller’s Continuum for enameling. It’s my fav silver
alloy.
Jo Haemer
timothywgreen.com
Sterlium plus, it's alloyed with 4% copper and 3% zinc,
I hadn't seen the Sterlium composition before
I was a bit surprised too. I had assumed for a while that Sterlium
was closer to Argentium, alloyed with Germanium among other things
(?not sure there). But I recently bought some sterlium casting grain,
and the paperwork from United Precious Metals listed the composition.
So it differs more from Argentium than I’d realized. But no matter.
For me, it does what I need it to do, which is not form fire stain
and much less fire scale. And it’s a bit cheaper, at least direct
from United. The lower amount of copper helps, and the zinc does the
same job of deoxidizing the metal when melting as it does with zinc
deoxidized gold alloys. Makes sense.
Peter
Would the zinc in Sterlium Plus mean that it's unsuitable for enamelling
Call up United Precious Metals who makes it, or Stuller who carries
it, and ask.
I’m sure someone would know. I’m guessing it might cause problems,
but don’t actually know.
Peter
And be sure to get “Lab” grade boric acid, it’s much finer than what
you getat the drug store so it mixes better. This also makes an
excellent anti-firescale (unless you overheat the metal.)
If you don’t use heated pickle, all you need to do to get “those
balls” of boric acid off your piece is to run it under HOT water for
a couple of minutes.
I should have said "enough of the needed copper" or some such. Frankly, the exact details of these alloys I don't have handy, but the basics is that they don't form that fire stain. In the case of Sterlium plus, it's alloyed with 4% copper and 3% zinc, rather than the germanium in Argentium. I'm guessing much the same happens, with the zinc keeping the copper from oxidizing as well.
From a JCK online article.
HOUSE BLENDS
A rundown of the most popular germanium- and platinum-based sterling
silver alloys on the market, who makes them, and what’s in them:
GERMANIUM-BASED ALLOYS:
Argentium International Ltd.
(London; 44-207-433-2572; argentiumsilver.com)
- Argentium 935 Original
93.5% silver; copper; germanium - Argentium 935 Pro
93.5% silver; copper; germanium - Argentium 960 Pro
96% silver; copper; germanium - Argentium 960 Pure
96% silver; copper; germanium
United Precious Metal Refining (Alden, N. Y.; 800-999-FINE;
unitedpmr.com)
- Sterling Super
93% silver; 3.9% copper; 3% zinc; germanium - Sterlium Plus
93% silver; 4% zinc; 3% copper; germanium
ABI Precious Metals (Carson, Calif.; 310-769-0600;
abipreciousmetals.com)
- Sterilite Sterling #122
92.5% silver; copper; tin; zinc; germanium; silica
PLATINUM GROUP ALLOYS:
Stuller (Lafayette, La.; 800-877-7777; stuller.com)
- Continuum
92.7% silver; 2.8% palladium; 2.8% copper; other proprietary metals
Hoover & Strong
(Richmond, Va.; 800-759-9997; hooverandstrong.com)
- Palladium Sterling
92.5% silver; 3% palladium; other metals
United Precious Metal Refining
- Silvadium
93% silver; 7% palladium; germanium - Platinet
92.7% silver; 5% platinum; other metals
ABI Precious Metals
- Platinaire
92.5% silver; 5% platinum; other metals - Elite Silver 950-3P
95% silver; various combinations of palladium, gold, and other
proprietary elements - Palladium Sterling
93% silver; 1% or 3% palladium; other metals"
James Binnion
Hello Everyone,
I have a question about firecoating and fluxing when using Sterlium. This is a new metal for me as I have been using 925, but got frustrated with it due to the amount of firescale I was getting. The pieces I make are generally made from .60 mm or 22 gauge sheet metal. It is annealed, hammered for texture, annealed again, bent and attachments are soldered on. With 925, recently I began using Dandix paste flux to coat my pieces as a fire coat and then used Batterns flux on areas I was soldering. It seemed to work pretty good and the metal was really clean after heating. However, I recently tried this on Sterlium, as I just did a series of pieces with it. It seemed to be working, but when I polished I swear I have some kind of firestain or even firescale. I am a pretty new silversmith and am still learning the appropriate size of flame for the right job, but I feel for these pieces I did not overheat them, but I must have! Sometimes I have to solder 2 or three times on a piece as I am using a a rounded wire as a bale for my piece, with 2 joins, and one doesn’t run properly on one side or it starts to get hot so I stop, pickle and resolder. I use a cold pickle of sodium bisulfate. It takes a bit of time to get the dandix off but metal is white. Also some of the piece had a yellowish staining, perhaps from the Dandix or the Batterns, I used Dandix it for a fire coat for annealing to. To finish my last solders on a few of these pieces I just coated the whole thing in Batterns flux as a fire coat and for soldering my joins to see if that would stop the staining. In the pieces I finished, I noticed a slight stain on a few, that seemed to polish off pretty easily. The pieces looked great, but today I looked at them and the high polished areas are stained. Any ideas on how I can prevent this in the future. In the past with 925, I had used the alchohol, borax fire coat, but here in Canada it is mainly methyl hydrate that is available and the reading I have done on it says it is highly toxic. Also my studio is in my house so I am trying to minimize fumes and will be putting in a fume hood this year. I appreciate the forum so much! Thank you in advance for an ideas or feedback on this, Nicolina
Hi Nicolina,
I think you’ll find everyone has their own alchemy that they use. I have great success with the old alcohol and boric acid fire coat/ flux. When possible I try and high polish very smooth things before I solder. I. Lay on or dip the piece in the fire coat and then I flame it off. ( Flammable so take great care and stay safe) Then I solder through the coat and I do it with green flux. Use Battern’s but use it as a flux only. The fire coat comes off with hot soap and water and it polishes up pretty OK. Give it a try.
But try what my brother Rob suggests, or Aurora, Jo, Ted Frater, Jim Grahl, Sharon… Don’t miss the chance to get advice from everyone.Have fun.
Don Meixner
Thanks Don! So using a flux as a fire coat could cause firescale maybe? Not enough protection for the whole piece while heating for annealing or soldering? So should the firecoat be visible after annealing or soldering? Thanks Nicolina
Hi again Don, I am interested in trying this water method fire coat you mention here. Does this recipe also work with Boracic Acid or do I need to buy pure borax if mixing into boiled water? Thanks again!
Sorry another add on to last post:
Also is it boiled after the powder is added or it water boiled then turned off and powder added? Thanks again!
This is the handout I give people about the flux I use. I really like this style of flux for silver, copper, and brass. You mileage may vary depending on the size torch you use. If I use a very small torch, then I will also use a drop of Battern’s on the seam.
http://livingstonjewelers.com/library/fluxrecipes.pdf
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Hi Nicolina,
More Likely to much prolonged heat has burned of the fire coat. Using Battern’s in my experience as a fire coat has sketchy results. That’s why I use the boric acid and alcohol solution. The results for be are more dependable.
I can’t even tell you the ratio of the mixture. I use it as I make it. A couple ounces of alcohol at a time with enough boric acid to have the consistency of milk.
Some one will come in with a recipe for Pripps flux. Try that,. It is used all over to universal success.
Don
Hi Nicolina,
I use boiling soapy water to clean off the flux after it is soldered. Other flux mixtures use water but mine doesn’t.
D
Thank you so much Don!
Thanks Gerald I will try this recipe, much appreciated!
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Hello Nicolina,
If you are working with the alloy Sterlium from Stuller or United Precious Metals, download the tech sheet from them. Then call Stuller’s tech folks with specific questions. I have found them to be very helpful. Sterlium is touted to be free of fire-scale, so the use of some sort of “fire coat” should not be necessary. Your photo shows what does look like fire scale - are you sure you did not grab a piece of standard sterling? I do note that the tech sheet specified using hot (not cold) Sparex for pickling, but the temperature should really only reflect the speed of reaction and not whether or not it occurs.
Although the tech sheet indicates that Sterlium can be fused without brazing/using solder, there are some joints that just beg for solder! I’d suggest fusing as much as possible and adding solder only when necessary. And again, do call Stuller’s tech folks for that actual human voice!
Just an aside regarding using alcohol to carry borax - ethanol will work and is not toxic…unless one drinks to excess. 
Around here, it’s sold as Everclear and college students use it for all manner of alcoholic punches. TMI!!
Judy in Kansas, where it’s time to take photos for jurying. Ugh. Not nearly as much fun as making the pieces to be photographed!
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Hi Judy, No it wasn’t 925 I used, I keep all my sterlium in the labeled bags it came in as I do have lots of 925 in my studio. Great advice will do. I will call them today. As I am still learning, I feel the overheating could be the issue and I remembered today the first piece I worked on of the Sterlium I did not use any coating as I didn’t think I needed it. But a few of the other ones have the same staining. I will confirm all this Stuller and see what they say. I did try making the Prip’s yesterday the metal did seem clean, but I am not at the polishing stage ;). I will look into fusing, I have never done it, so I will look into this and try it out.
Many thanks and best of luck on your jurying! Love to see your work.
All the best, Nicolina
The following is a good solution, originally taken from the Goldsmiths’ Co special report no.15 in 1972 by Peter Gainsbury, and good for inhibiting firestain on silver. Also effective on gold, copper and brass.
Boric Acid Powder 106.4g
Di Sodium Hydrogen Orthophosphate 12 Hydrate 70g
Sodium Hydroxide (Caustic Soda) 7g
Borax Powder 70g
Washing up liquid 28.4ml
Purified water 1.5 lit
Weigh out the chemicals and slowly dissolve in warm distilled water. The solution doesn’t seem to deteriorate with age, althoug less effective if dirty.
Best - the metal should be warmed and the solution sprayed or brushed all over so that is hisses & dries on the surface. Can be also used cold for both annealing and soldering.
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