enbarro Posted November 25, 2014 Report Share Posted November 25, 2014 Hi, my local store is out of epk. I rather wait until I run out of other materials before placing an order. I have a few #s of tile 6 and plenty om#4... The recipe I want to try is the one Niel posted a few days ago... cone 04-03 siglefire. I'm ok with cloudiness and will also try 10% zircopax Ferro 3124 90% EPK 10% + veegumt/bentonite Anyone knows which would be a better sub or have any advice? thanks, Link to comment Share on other sites More sharing options...
bciskepottery Posted November 25, 2014 Report Share Posted November 25, 2014 Tile 6 is a kaolin, as is EPK; OM#4 is a ball clay. A kaolin for a kaolin might be the better substitute. Or, make a test amount of both and see which turns out best. Link to comment Share on other sites More sharing options...
Mark C. Posted November 25, 2014 Report Share Posted November 25, 2014 #6 tile as noted above is kaolin OM4 is not. Mark Link to comment Share on other sites More sharing options...
Tyler Miller Posted November 25, 2014 Report Share Posted November 25, 2014 Tile #6 is pretty close to EPK. Like 0.25% less iron, and +/-1% Alumina and silica. OM4 has more a bit more silica (10-12%) and less alumina, and like twice the iron of EPK. Tile #6 is probably your closer bet, but test tiles to be sure. Full disclosure: I've subbed in Om4 before in a recipe like this, didn't really matter--maybe a slightly warmer hue due to the extra iron, and very slightly glossier. Link to comment Share on other sites More sharing options...
TJR Posted November 26, 2014 Report Share Posted November 26, 2014 You guys didn't think of this.. What kind of pottery supply store runs out of EPK.? This is a pottery supply that will soon be out of business. Tile 6 is a kaolin, Om4 is a plastic ball clay. If you are raw glazing, the ball clay would be a better substitute for glaze fit, but it is not a kaolin. Why not test both? TJR. Link to comment Share on other sites More sharing options...
enbarro Posted November 26, 2014 Author Report Share Posted November 26, 2014 Thanks to all, I'll try both... One of the reasons I'm considering om#4 is because I thought it might help solve the powdery unfired surface typical of high % frit glazes... Why would a ball clay help with raw glazing? Link to comment Share on other sites More sharing options...
Mark C. Posted November 26, 2014 Report Share Posted November 26, 2014 Its shrinkage will be similar to the raw pot as it is clay causing less issues as it dries. Mark Link to comment Share on other sites More sharing options...
TJR Posted November 26, 2014 Report Share Posted November 26, 2014 Like Mark said, it's the shrinkage. It will shrink more than the kaolin and will adhere to the pot better. It also has a harder surface. TJR. Link to comment Share on other sites More sharing options...
neilestrick Posted November 26, 2014 Report Share Posted November 26, 2014 You guys didn't think of this.. What kind of pottery supply store runs out of EPK.? This is a pottery supply that will soon be out of business. TJR. Having been a production manager for a clay company, I can say that it's not that difficult to run out of EPK, or any other type of clay or glaze material for that matter. There is a finite amount of space for each raw material in the warehouse, and there fore you have to carefully time the purchase and delivery of the materials, especially those which you buy in large amounts like full truck loads. You have to track your clay mixing schedule to make sure you have enough of the needed raw materials on hand to keep production moving, and place the order 'just in time' so that you have space in the warehouse for the new material as the old one gets low. If the mine gets behind schedule filling orders, or there's a problem with trucking while you're using up to several tons of the material each day, you could easily end up with a day to a week or more where you run out. Also, it's possible someone came in and bought a whole bunch and wiped them out. It happens all the time. So yes, at those times you have to be wiling to substitute. This question could also be posed by the pottery supply company to the potter/customer- why did you wait until you were out before you ordered more? I know it's easy to vilify the pottery supply store every time something affects you in your studio, but there are a lot of factors at work here. If huge companies like Target or Home depot can run out of things, why can't the pottery supply store? Link to comment Share on other sites More sharing options...
enbarro Posted November 27, 2014 Author Report Share Posted November 27, 2014 Thanks Mark and TJR. I might just try the om#4 version then. It seems to be what I'm looking for. I try to order everything, all at once, several months in advance of high seasons. Thanks Niel for the recipe. Other cone 04 industry recipes are highly welcomed. Link to comment Share on other sites More sharing options...
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