I have been working with PMC for only a few months and purchased a tumbler to use with stainless steel shot for extra burnishing. The first time before I used it I cleaned it out well and washed the shot mix. and everything came out black.  I was petrified, so I re-fired it and it looks better but not quite like it looked when I took a class and was under my instructors supervision. could anyone tell me what I'm doing wrong.  One of the pieces actually turned kinda brownish snd looks like I patina'd it and is not so bad.  But even after re-firing the others they still look like crap.

                                                                    Thank You!

                                                                   beadmanic

THAT happened to me, once (except it was a custom order, three days before Christmas -- EEEEK!)

 I took a D-E-E-P breath and said, "this can't be happening!". Then I ran the shot through a full cycle IN the tumbler (shot, water, Ivory liquid soap for me). Three hours later, I washed the shot and it was BLACK. Did one more, shorter cycle and this time the water was clear. Retumbled my piece and life was HAPPY HAPPY HAPPY.

 
Try running your tumbler with shot, water and cleaning solution for a few hours to clean out whatever "gunk" remains from the manufacturing process. Let us know what happens.

 
BTW: I'm glad you knew the trick about throwing the piece back in the kiln. Not all instructors remember to mention that!
 

I've never tried it, but I hear you can clean your shot with flat cocoa-cola in your tumbler. Alice

I use my tumblers constantly (I have 6 - usually three or four running at a time) and always have that problem until they get broken in. The rubber breaks down slightly and deposits on the silver - but it's easy to wash off with hot water and a heavy dose of a grease fighting dish detergent such as Dawn. I also use copper in some of my pieces. and when I tumble a lot of copper and silver together, I get a reddish - black film on everything - again, dish detergent removes it.

Yup, Alice is right. I've used flat coke to tumble with my black ss shot and it worked a treat. Be certain it's flat before you do tho!

Are you saying that flat Coke removes the black tarnish on my stainless steel shot?  Will it do the same for my PMC pieces?  I just had a whole tumbler full of pieces come out with a brownish patina.  The shot is now the same color.  I emptied and rinsed everything, put in fresh water and a good-sized squirt of Dawn and ran it again for 2 hours.  Not any better.   I've been using this particular tumbler for several months with no problems at all.  I can't figure what made this happen.  Does anyone know?

I'd be interested to know as well.  I've been using my tumbler for a while and no problem - I put several pieces in (silver, but no PMC) and everything is black.  I had used tripoli in it previously, but I cleaned out the shot and tumbled alone with detergent.  Tried washing the pieces off individually, but I still have a blackish finish - not at all the nice shiny finish I'm used to.

SO good to hear that others have this problem!! Not good that we have the problem, of course, but I have asked around locally and no one knew what I was talking about!! I went with Steel Shot Restore from Santa Fe Jewelers Supply  - www.sfjssantafe.com to restore the shot - works better than soap, burnishing compound, or flat coke, IMO, and I keep a seperate canister with walnut to burnish the finished pieces. So, in other words, I do two steps - tumble with shot to work harden for 4 - 6 hours, then tumble 1/2 hour with walnut to shine - works great on my sterling and mixed metal chain.

Thanks for great topic! Sam@sterlingbliss.com

Hello, I am a jewelry fabrication teacher. We use a tumbler and have had this problem in the past as well.  Some students do make copper and silver pieces but we are not sure if this is the reason items can turn black, so if possible keep a separate barrel for silver only.  One solution to cleaning the steel shot is to make a slurry of baking soda and water and tumbler the shot for a couple of hours.  It's a great cleaner...

I banished my black rubber tumbler containers to the closet a long time ago. They were too hard to open and close. They also made me have to clean the shot more often. What do I use? A glass jar with a tight fitting, screw-on lid. My first try was a mayonaise jar which worked fine but my new jar is a winner. I think it held marinated artichoke hearts. The winning shape has straight sides. No, the goings on inside are not rough enough to break the jar. You can watch, if really bored. The motion resembles ocean waves more than anything. Load the jar with the lid towards the motor where there is a space without the plastic that shields the rotating spindles. Try it. You'll like it! Oh, a wet jar slips. If it leaks, line the cap with something.

Love that idea!! Two of my tumblers are in need if replacement, so I'll try replacing them with jars...and I love artichokes, so it's a bonus! :) I still go with Dawn and Sunsheen from Rio as a fix for the black deposits, but I'll also try the baking soda. Now I have a question - has anyone had a problem with a white film that shows up on their pieces after a day or two? I'm wondering if it's a reaction to city chlorinated water. Any ideas?

Make sure that you are not using a detergent with citrus as that will turn your silver black. I usually use regular Dawn, but one time I was out and used my dish liquid from the house which had lemon and everything was black. Tumbling it a few times with Dawn and rinsing in between got stuff shiny again.

Diane

 Thanks for the tip on using baking soda.  If it cleans the shot will it also help take the patina off my silver pieces?  I bought dry burnishing soap and tried that today and still no change.  Right now I've got my shot soaking in Coke (while waiting for it to go flat) and I'll give it all a whirl in the tumbler after a while.  Does anyone think that pickling will take this stuff off if nothing else works? I'm afraid to keep tumbling the pieces because of their becoming too work hardened.  Any thoughts on that?

I like the glass jar idea...very clever. 

Thanks everyone for the tips, I was sure glad to know my pieces were restorable. I'm going to try all idesa to see with one works best for me and the glass jar sounds pretty original and you could see the pieces as your burnishing them. I'm very visual like alot of us artist's so I would find that interesting to see. ( for a short time of course)

                                                                    Happy burnishing

                                                                                     beadmanic

 Hello,

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You never should tumble base metals like brass or copper in the same tumbler you use for silver. Also no work piece that is a combination of silver and base metals!  The copper and copper alloys are more base than the silver, so that a fine film of copper settled to the silver surface during tumbling. The silver looks less or more brown and if you use brass sometimes golden.

If that happened, you can remove this settle if you put the piece in a cleaning bath for silver.

 

Before you use the tumbler again you must remove the copper from the shot. At first discharge the contaminated water from the tumbler, put the shot in a sufficient household sieve  and wash the shot under running water and give it back to the tumbler.

A quick but a bit dangerous  method to clean the shot is to use a pickle like 10%  sulphuric- or hydrochloric-acid.. But you should use acids only, if you are familiar with the use of acids!! Put the diluted acid for only 2 minutes so in the tumbler, that the shot is acid-capped. Discharge the acid and fill and remove water 3-4 times in the tumbler with the shot. After that let the tumbler run with water and neutral-soap ( curd soap works well) for ½ hour. Remove the soap water and rinse again 2 times with water.

An other more safe method is to use a 10% Alum-solution. Alum-salt you get in drugstores.

Fill this solution in the tumbler and let the tumbler run for an hour. The solution works better, if you warm it up to about 50-60 degree Celsius = 120-140 degree F. Remove the solution and clean tumbler and shot as described before.

I hope this is understandable and sorry for my bad English.

Edmund  

http://www.emailkunst.de

I hate to be a naysayer, but I simply don't believe that firing/tumbling mixed metals is that big a problem. I've been doing it for quite a while, and although I do see a SLIGHT copper residual on my silver pieces, it's not that difficult to remove. I tumble everything with a combination of Dawn dishsoap and Rio's Sunsheen Burnishing liquid, then rinse well. I oxidize at that point with liver of sulfer, and rinse again. Polishing comes next, with a handheld tool - I actually have a Dremel tool with a flex attachment - and a block of red rouge. A final wash in the tumbler for a short time (Dawn, again) and everything comes out sparkling! Another thing that I was led to believe ( I am inclined to call these the old wive's tales of AC) is that no piece can touch in the kiln when you fire, or the pieces will be inseparable. Simply not true. I have a number of small pieces - charms and tags - that I can't take the time to lay out on the shelves because I fire 150 - 300 at a time. I sprinkle them on the shelf, and fire them as they lay - and guess what? They pop apart easily, and often I just toss them in the tumblers and let the shot do the work.

Hello LZ,

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I hope my English is not so bad, that I get misunderstood.

 

I hate to be a naysayer, but I simply don't believe that firing/tumbling mixed metals is that big a problem

 

Firing base metal and precious metal in the same kiln or also together at the same time is no problem, if the both metals are not in contact. If both metals are in contact, an alloy is produced far below under the melting points of the both metals. A simple example: The melting point of fine silver is 961,78 degree Celsius ( about 1763 Degree F); the melting point of Copper is 1084,4 degree C ( about 1983 degree F) But the alloy Sterling silver = 92,5% fine silver and 7,5% copper has a melting point of 779 degree C ( 1434 degree F) So the melting point of this alloy is round about 182 degree C ( ~360 degree F) lower than the melting point of the fine silver.

And such an alloy get formed if you fire copper in contact with silver by temperatures of about 800 degree C (1472 F), so much lower as the melting points of the both pure metals! Many enamellers knew that from her experience if they use fine-silver-wire direct on a copper surface.

 

But I think that was not the primarily question. The question apply to the brownish shine on silver surfaces after tumbling and how to remove it. And so as you wrote, you also get a light brownish deposition on your work. That is not a problem, if you sulphidize the work after tumbling, but if you want to have a silver white shiny surface, you must remove the brownish. And that you can do as I described before.

 

Why did you get the deposits? If you tumble the work with water and stainless steel shot, little parts of the metal surfaces get rubbed off. And because of the electro-chemical downward gradient between base metal and precious metal, the rubbed off base metal deposits to the precious metal. That is an electro-physical law!!

 

Another thing that I was led to believe ( I am inclined to call these the old wive's tales of AC)

I think this is a bit unfriendly and unqualified sentence!

is that no piece can touch in the kiln when you fire, or the pieces will be inseparable. Simply not true.

That is only a question of the temperature. If the kiln temperature is higher than the melting point of your charms and tags, you get a nice chunk of that!!

I have a number of small pieces - charms and tags - that I can't take the time to lay out on the shelves because I fire 150 - 300 at a time. I sprinkle them on the shelf, and fire them as they lay - and guess what? They pop apart easily,

I think your charms and tags are all from the same metal and you fire it well below the melting point of that metal. Or if you have a mix of precious and base metal the kiln temperature is so low, that no alloy get formed!  But if you mix precious and base metal and fire the tags at the same temperature as before, you get a nasty surprise!

Edmund

http://www.emailkunst.de

 

 

 

 

Edmund, I am not trying to argue with you - you obviously know your metallurgy. And I understand the principles you cite. All I am doing is letting everyone know MY experience with mixing metals. It's my observation that too many people starting out with silver clay are scared away by the long list of "do's, don't's and nevers", and it took me three years of experimentation to realize that rules are meant to be broken sometimes. I fire for 1 1/2 hours at 1350 F. My copper and silver clay pieces are made and fired with the clay affixed to the copper. I tumble silver and copper together, and when I say that there is a SLIGHT film, I mean it. It's almost imperceptible. Once I oxidize the pieces (and most areas are not oxidized - I use a brush to control where it happens) I polish them with a cloth wheel and red rouge. Any copper on the surface comes off with the buffing. This is not unusual - I made the mistake a while ago of polishing my wedding rings this way, only to find out the hard way that 'white gold' is electroplated onto yellow gold. My rings are now in need of a new coating of white! My pieces are very shiny and have no trace of a brown or yellow cast. Now, perhaps this will not be everyone's experience, but it's worked for me.

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Hello Lee,

You are right. In some so-called “reference books” you find a lot of bosh! Particularly if they were written by laymen, who believed, they would be specialists after some weeks of experience. But it will transfer also much nonsense from one technical book into the other one, since some authors save self-experiments. I do it like you, I try out the “do’s, don’ts or nevers” by myself. And if it works for me, it is o. k., if not I try to change the technique and to find an other way.

With friendly regards from the today hot Bavaria/Germany

Edmund

  

Hello Edmund,

I am so grateful to read your information.  I just bought a tumbler and would have been horrified with this "unspoken" problem.

Also, please don't apologize for your English skills.  They are great. I am also a technical writer, and what you said was perfectly clear.

Thanks,

Norine.