TypicalGirl Posted January 27, 2012 Report Share Posted January 27, 2012 OK, simple question time... Firing a downdraft kiln to cone 10. I have some flat pieces that I want to be able to move on the shelf during the firing and I hear tell one can sprinkle sand on the shelves to facilitate that. Is this special Potters Magic Sand, or something I can get at the hardware store? Anything I need to be aware of? Link to comment Share on other sites More sharing options...
Mark C. Posted January 27, 2012 Report Share Posted January 27, 2012 Yes its not hardware store sand which can be not clean enough(can flux)-The silica sand I have used is from Laguna Clay co-its cheap enough but also clean enough so it does not flux to things I have 100#s of it and will ups ship you some(5-10#s) if you pay the shipping?I think they only sell it in 100#s as ordered 50 they sent 100# an charged me for 50# If you are firing alot you should test any hardware store sand 1st before committing work to it. Mark Link to comment Share on other sites More sharing options...
TypicalGirl Posted January 27, 2012 Author Report Share Posted January 27, 2012 Thanks Mark! Let me check with Quyle and see if they have any hanging around, and if not, I'd love to get some from ya! And thanks for the heads up - I'd hate to screw up Precious or her new shelves Link to comment Share on other sites More sharing options...
neilestrick Posted January 27, 2012 Report Share Posted January 27, 2012 Silica sand only. Your local clay & glaze material supplier should have it in stock. It's a great way to go with large or sculptural items. Just a fine dusting will do the trick. Keep it from the edges of the shelf so it doesn't fall onto pots below and get stuck in the glaze. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted January 28, 2012 Report Share Posted January 28, 2012 OK, simple question time... Firing a downdraft kiln to cone 10. I have some flat pieces that I want to be able to move on the shelf during the firing and I hear tell one can sprinkle sand on the shelves to facilitate that. Is this special Potters Magic Sand, or something I can get at the hardware store? Anything I need to be aware of? I don't like sand nor grog because it can end up inside other work below. I find using small extruded coils work well for allowing movement and heat circulation for flat pieces as well as large pieces like footed serving trays, bird bath stems, etc. Marcia Link to comment Share on other sites More sharing options...
TypicalGirl Posted January 28, 2012 Author Report Share Posted January 28, 2012 Thank you all for the input! I've also heard of folks using "wads" of kiln fiber under flat pieces to allow them to move. I don't usually have a problem, but I'm starting to play with some tray and plate forms and so am looking for ideas. Have a great weekend everyone! Link to comment Share on other sites More sharing options...
neilestrick Posted January 28, 2012 Report Share Posted January 28, 2012 OK, simple question time... Firing a downdraft kiln to cone 10. I have some flat pieces that I want to be able to move on the shelf during the firing and I hear tell one can sprinkle sand on the shelves to facilitate that. Is this special Potters Magic Sand, or something I can get at the hardware store? Anything I need to be aware of? I don't like sand nor grog because it can end up inside other work below. I find using small extruded coils work well for allowing movement and heat circulation for flat pieces as well as large pieces like footed serving trays, bird bath stems, etc. Marcia For high fired work (cone 6 and up), pyroplasticity (pieces warping as the clay approaches its melting point) can be a real problem. Sand is ideal because it provides an even surface for the piece to sit on. There are no pressure points or unsupported areas. If you choose to use wads or coils or such, use a lot of them and make sure the piece is evenly supported underneath. This is always an issue in wood and salt/soda fired pieces that have to be perched atop refractory wads. Platters and plates love to warp if you don't get enough wads under them. I've even seen slab pieces slump down over each wad, leaving little peaks in the surface. Link to comment Share on other sites More sharing options...
Mark C. Posted January 28, 2012 Report Share Posted January 28, 2012 In cone 10 work this has worked for meI made a thin clay slab same size as large piece-in my case this piece was 36 inches long x 22 wide-fired on top shelve of car kiln I also have a baily power slab roller so it was easy- I bisqued and glaze fired them together and the both shrunk together-this worked well to bridge the gap between the 3 12 x24 shelves for support The only down side is the slab is pretty much useless afterward The silica sand works well just be careful about letting it get loose Mark Link to comment Share on other sites More sharing options...
perkolator Posted February 9, 2012 Report Share Posted February 9, 2012 OK, simple question time... Firing a downdraft kiln to cone 10. I have some flat pieces that I want to be able to move on the shelf during the firing and I hear tell one can sprinkle sand on the shelves to facilitate that. Is this special Potters Magic Sand, or something I can get at the hardware store? Anything I need to be aware of? a little late but... when we fire large-scale flat pieces (24"x36"), we like to set it on lots of small balls of kiln putty/wadding so it is evenly supported and won't drag on a shelf when it moves. it also helps solve the dilemma of schmutz falling on work down below. our wadding is equal parts silica, kaolin, and grog, and we make balls about 3/4-1" diameter depending on how large/heavy the slab is, or how warped the shelf is, lol. if you're talking about physically sliding a large, heavy object into the kiln - we like to use grog underneath to reduce the friction and facilitate sliding, silica sand would work too. put newspaper under the shelf if you're not sliding onto the floor shelves, to catch anything that wants to fall on a piece below. Link to comment Share on other sites More sharing options...
Diana Ferreira Posted February 9, 2012 Report Share Posted February 9, 2012 We use Alumina on our kiln shelves. Put the alumina on the shelve before you stack it. I use a shoe brush to make sure that there is no alumina lose to the edge. I normally just remove my shelves, with the alumina on it, and stack it on 15 mm shelve stacks. that way the bottoms does not become contaminated with the alumina. And for a new range I cut some supports out of plaster, and casted them in the same clay that I use. When I re-use them I sprinkle Alumina on the support to ensure that my piece can slide/move on the support. Alternatively you can use a lot of alumina - make a little mountain of it on the shelve, and twist your piece into it, so that it is embedded. Obviously you will not do this if the outside of your work is glazed. I rarely glaze the outside of my work ... Link to comment Share on other sites More sharing options...
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