Raising and Annealing Sterling Silver

[Matt Ferrari]

Hi, guys. I wasn't sure where I should post this, but the "Vessels and Bowls" section seemed to make the most sense, since I'm trying to raise a silver cup.

A local metalsmith recently taught me how to raise a copper cup. The results were quite encouraging, and I'd post some pictures of the piece, but I haven't had the opportunity to take any yet.

I'm going on vacation, and want to try raising a sterling cup. But that also means that I want to take along the least amount of equipment I can.

So here are my questions:

1) Do I need to flux the sterling each time I anneal it? (I didn't with the copper.)
2) Do I need to pickle the piece after each annealing? (I did with the copper.)
3) Can a Prest-O-Lite propane torch deliver enough heat to anneal and solder the work?

I'm accustomed to having hot pickle and acetylene at my disposal. Are there alternatives that I can get at, say, the local Home Depot? And is it best to anneal sterling with flux to prevent any fire scale, or can I anneal it untreated?

Thanks in advance, and I promise to post pictures of both pieces,

Matt

[bherman]

Hi Matt, I'm not an expert but, I have worked with sterling silver. There's some examples in my gallery. The flux helps prevent oxide development during the annealing process. If the oxides are allowed to develop, surface damage is the result. Depending on the degree of damage extra work planishing, burnishing or sanding in the extreme case will be required. In silver or goldsmithing sanding anything but a casting is considered a faux pau.

The pickling, which helps to remove the flux and the oxides can be accomplished by using your pickling solution in an old crock pot. Pickling after each operation is quick if you keep your pot hot and helps keep the surface free of contaminates. Be sure the flux is completely removed form the entire part before you work it. Flux is HARD, it gets shocked loose by your hammer and ALWAYS finds it's way under your hammer face!

It's been a while since I worked with sterling and I don't remember the annealing temp, but it's easier although somewhat tedious to get an even anneal with a heat source that is closer to your ultimate temp. Your propane if it gets hot enough may be a better choice.

Good luck and show us photos of your progress.

[kerrystagmer]

pickle need not be hot! IT was a suprise to me when I first worked with a silversmith who doesn't hot pickle. We just keep our pickle in a plastic tub (with lid of course!) and pickle for about 6 min and check.

Always pickle after annealing or you will pay the price when you try to get a good finish.

I have never fluxed when raising, but perhaps it could help?

If your using sterling you will need to anneal often, basicly each time you completely hammer the part over once. If your working in Fine silver half to 1/3 that.

you will love the results that silver gives once your planishing, its much like a jeweled surface

[Matt Ferrari]

Thanks for the replies, guys.

Because I'm driving, I'm probably going to take a lot of stuff with me. And now that I think about it, I've used propane to anneal aluminum before. The annealing temperature of aluminum is close to sterling's. As I remember, it was slow going, but it'll do.

Brian, do you know of a little street in Royal Oak named Hawkings? It runs one block off of Woodward, parallel to it, perhaps around 12 mile road, or wherever the old FIAT dealer was? That's where my grandfather, Amerigo Ferrari, lived, although he passed on a good number of years ago. He was a master tool-and-die man.

Kerry, you make a great point about pickle temperature. It works at room temperature, but takes a litlle longer. Do you happen to know what kind of plastic container you use? Could the pickle eat through some types, and not others?

I should also say that both of you described the process I'm using very well. If anyone reading this wants some more information, I'd recommend the book "Silversmithing" by Finegold and Seitz. I'll also post a how-to later, along with pictures.

Thanks again. This is one great forum!

--Matt

[Matt Ferrari]

By the way, I'm having troubles uploading pictures into "My Gallery". Is there something going on, or am I doing something wrong?

Thanks once again,

--Matt

[Matt Ferrari]

By the way, I'm having troubles uploading pictures into "My Gallery". Is there something going on, or am I doing something wrong?

Anyone? I think I need a primer on MetalMeet picture work (even though I've gotten it to work in the past....)

[jvo]

Matt, there's lots of info on the main page, at the top, tutorial on how to use the site, and photo gallery problems, or just wait long enough, and Anders will pipe up and show you. John V.O.

[wtowns01]

Matt, I have not been reading the post as often as I should, hope it is not too late.

As far as annealing. What ever you use for a torch it should have a bushy flame so you do not get "hot spots". A propane torch will work if the piece is small enough and the gage of sterling silver. Here is a little movie I made a long time ago. I am using my rose bud here and oxy/actylene.
https://home.comcast.net/~wtowns01/Movies/annealingmovie.WMV

To protect the silver from fire scale or fire stain (ugly gray stuff) you must protect the silver during annealing. For this I am using 2 parts denatured alcohol and 1 part roach kill (boric acid). Apply with brush, light the alcohol and then heat with the torch.

As far as pickle, what are you using? I get a lot of people tell me they are using swimming pool PH down. I have never tried, but in order for it to work it must be warm (150F) which I think is not very safe in the first place. So I stick with my battery acid pickle (sulfuric acid) of 10 parts water one part acid, and use in a regular rubber maid tub with a lid at room temperature. The pickle will not harm the rubber maid container but a little rough on the clothes (eats holes or fades outs) and you should wear rubber gloves. As long as you had a container that could seal up tight during transportation you should be okay.

Matt are you from Royal Oak, MI?

[butch foster]

Warren - Great movie. Couple of questions though. I've never annealed sterling before but read that you need to achieve a certain color as you heat it and I believe they talk about doing this under very low light so you can see the subtle color changes in the piece as you heat it. The background in the movie seems to go dark at some point. Did you turn off the lights in order to see the color change and if so, what color are you looking for? I believe the book described it as a straw color, but I honestly can't remember. Second question. You wash the piece in two solutions. Is the first pickle and the second water or the other way around?

Thanks. Nice piece of work BTW.

Butch.

[wtowns01]

Butch, thanks on the movie, I was just messing around one night and taking small clips with the digital camera.

On the color. The sterling silver will actually glow a dark red under darker lights. I tried to show that but my timing might of been a little off. The straw color is referance to the color the flux, like in Pripps fluxs gets after it comes to the correct temperature, it will become hard and like a coating then. Pripps is a special mixture of TSP, borax, and boric acid used to coat the silver when soldering, and can also be used to solder. The straw color lets you know that you can let the piece cool and do any wire tying or adjust of the pieces and the flux will not rub off in your hands.

What you will actually see, if you use the roach kill and alcohol mixture, is the mixture will be white to start. Low heat to just kind of glaze or melt some, then with a hotter flame and when the silver is close to turn red the mixture will look like glass or really wet. Kind of if you braze how the flux glasses.

On the two containers, the first is water, the second is the pickle. You do not want to put the hot silver in the pickle. Makes a nice stingy fume and ain't good for you. I also use the water to rinse off the piece after pickle.

[butch foster]

Thanks Warren. That helps.

Butch.

[Matt Ferrari]

Great video, Warren!

In the 2:1 alcohol to roach kill, is the "roach kill" 100% boric acid? Or 100% Raid, or whatever is commercially available? Isn't it a little nasty to breathe?

Also, where exactly does one purchase sulfuric acid? Is it readily available? Aside from working better at room temperature, is there anything else to consider? Is it possible to leave sterling in H2SO4 for too long? Does it eat at solder?

And what music are you listening to? ;)

(My father grew up in Detroit; I gre up in Pittsburgh, and live there now.)

Thank you very much,

Matt

[wtowns01]

Matt, okay the radio station is WCSX, classic rock. I was really surprised how much the camera picked it up.

On the roach kill, go to Home Depot or Lowes and they have the roach kill, $1.98 for a bottle of it. Probably be 99% boric acid. No not really that bad because you are not really inhaling it. When you light the alcohol make sure you have good ventilation because it can get you drunk, not really but the fumes are not good for you.


The sulfuric acid is just battery acid. Murrays or any other auto parts store sales it. Under $4 for a small box/bottle.
If the pickle is heated and the piece left it there a couple of days it will eat at the solder some. I have left stuff over night many times and no effect.

Happy hammeriing

[Matt Ferrari]

Thank you very much, Warren!

[MattV]

Just saw this thread and thought to throw a couple things out.

When doing all of this you definitely want to ventilate well. For keeping your silver clean there are some commercially available sprays out there as well, check out Rio Grande they are a jewelry supplier. For sulphuric acid there is a drain cleaner available at most hardware stores that is 98% sulphuric acid, it works fine (various names, usually is bagged) in dilution. If you are not thrilled with the acid there are commerically available pickles or an old fashioned method use vinegar and salt. It makes a nice, but smelly, pickle. Takes a little longer but works well.

[kerrystagmer]

I'm having trouble keeping the acid powder in solution. (denatured alky)

any suggestions? or is that just the way it is?

from a 6" round I'm 3 anneals into it and its down to -5 1/2" and about 2.5" deep. The cup will be around 3" at neck (18 or so anneals?) and slightly curved, perhaps with a light flair at the top. It will be completely chased by monday a week from now so i better get moving on it! 18ga sterling..

[wtowns01]

Kerry, sounds like you are moving right along. Just getting past the first three rounds is the hardest.

The boric acid settles all of the time. I usually stir it up before I use. Also the alky evaps and you have to add a splash now and then.

[kerrystagmer]

I'm planishing now but racing my deadline. I'm under 4" across at the top and about 5" tall with a slightly bulbus shape. I have to have it completely planished ANNEALED, polished and filled with red german pitch sometime around noon tomorrow (today as its 227am!). Doable but I have my entire weeks shipping to finish at the same time.

stupid camera is broken, but while im in NYC with Valentin I should have access to a camera at the palce I'm staying.

thanks for the info on the coating, seems i was doing it right.

Kerry Stagmer