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Sanding/polishing porcelain beads in a tumbler Answered

I'm looking to tumble porcelain bisque (not the final firing, still soft enough to sand off impefections), and polish the final fired porcelain beads in a tumbler. See attached photos of a final fired porcelain bead for the scale.

I'm wondering if you know what media, burnishing compound etc I should be using, and for how long.. I already have a 3lb capacity Lortone Tumbler with stainless steel shot currently for polishing metal. But I believe this tumbler also does rocks.

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Triclaw (author)2014-08-05
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caitlinsdad (author)2014-07-04

Your attempts at spamming that site all over the site are not welcome.

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Triclaw (author)Triclaw2014-06-25

ok I get what you are doing now , by hand would be a ton of work . Use grog at a 50 or smaller mesh and I would not add any compounds to the tumbler it will mess with glaze if that's what your going to do with it.. I would fill the tumbler tight with the beads then add the grog stop and check half hour intervals . As for small river rock can get a pet or craft stores its the natural polished stones . Antler is harder to get but it can be cut and shaped to fine blunt point to smooth clay and burnish it

http://ceramicartsdaily.org/pottery-making-techniques/ceramic-decorating-techniques/going-low-tech-a-step-by-step-guide-to-burnishing-pottery/

Also I forgot that porcelain does not burnish well ,Sorry been a bit seen ive worked with porcelain

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jarris (author)Triclaw2014-06-24

Any particular type/size? And should I add any burnishing compound?

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Triclaw (author)2014-06-25

35 to 50 you will have to keep an eye on it .Why do you want to polish it as bisque you can burnish it in green state very easly and get a great polish that way with some river rock or deer antler , the tumbler is going to eat away the detail and make it round if you leave it too long I would suggest to try to burnish it as green ware leather hard either way glaze will be hard to stay put on a polished bead

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jarris (author)Triclaw2014-06-25

Burnish by hand? The idea is to be able to produce these a little more easily by incorporating mechanical methods. First, I need to take a layer off as the way the beads are created are by joining two halves, sometimes the slip spills out and I have to fix the seam. In the process the marbling is sometimes covered by a layer of the joining slip, and ends up a bit muddy. By sanding at bisque I can take off a layer and reveal the marble beneath.

So before I burnish I do need to make sure that the seam is seamless and that the marble is revealed. Because this is porcelain, I find that sanding at bisque gives me a finer surface because of the 12% shrinkage compared to no sanding. And I can't imagine the objects would lose a huge amount of detail, they are fairly abstract, no surface design.

Also if I do sand at bone dry I find it quite difficult to tell what has been sanded vs what is dust settling in surface depressions. When I sand at bisque I can at least wash the bead and see what I'm dealing with.

I'm not sure what you mean by river rock or deer antler? Where do I get these in smaller scale and with a defined edge. Most of my work does have a somewhat sharp inner line that needs to be sanded/polished.

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caitlinsdad (author)2014-06-07

I'm not sure but look at harborfreight for their sandblasing media which is also used for the rock polishing/tumbling thing. I would say getting some of each type to experiment wouldn't be too costly. I got a box of the 80 grit glass microbead media for one of my projects. I think they have stuff that ranges from soft walnut shells to progressively harder media which might be appropriate to tumble for polish. Good luck.

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