Retxy Posted September 7, 2023 Report Share Posted September 7, 2023 Hi everyone! I have found a clay body that I like that I'm mixing myself but that is listed as a white firing body but is actually coming up rather creamy in color. I have learned that the om4 in the recipe can make it fire that way (thanks to digital fire) but to precipitate out the impurities barium carbonate is suggested and im not a fan. Any thoughts on how I can get it to burn pure white? I've got some glazes that are dulled by the creamy color but look so good on whiter bodies and I'm really enjoying the other properties of the body. Mason stains are too expensive so white body stain is not an option. I also considered a different ball clay, but Tennessee 10 for example was too refractory and I think I will lose the vitrificationof the body with a more refractory ball clay. Is there another ball clay that could work? Recipe is om4, neph sye, talc, and 3269. Thanks in advance, Ret Quote Link to comment Share on other sites More sharing options...
Babs Posted September 7, 2023 Report Share Posted September 7, 2023 You could coat your ware with a white slip if yoy cant get a white body Retxy and Rae Reich 2 Quote Link to comment Share on other sites More sharing options...
Min Posted September 7, 2023 Report Share Posted September 7, 2023 So you are making a lowfire fritware? Is this a casting body or a throwing body? Have you tried a white firing kaolin instead of the ball clay? How much talc is in the body? If there is a significant amount of talc have you tried firing some to see how white it fires? Retxy 1 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted September 7, 2023 Report Share Posted September 7, 2023 13 hours ago, Retxy said: to precipitate out the impurities barium carbonate is suggested Barium carbonate will only precipitate out soluble salts not the iron etc. impurities. I would try every clay you can buy and see which one works the best. Babs and Retxy 2 Quote Link to comment Share on other sites More sharing options...
glazenerd Posted September 7, 2023 Report Share Posted September 7, 2023 Talc has high magnesium, up to 20%: which can alter color. Ball clays need to be under 2.00% total iron and magnesium to keep the color on the white side. C&C ball clay would be a choice. Aluminum content dictates refractory limits. Tom Retxy and Callie Beller Diesel 2 Quote Link to comment Share on other sites More sharing options...
Retxy Posted September 10, 2023 Author Report Share Posted September 10, 2023 @glazenerd @High Bridge Pottery @Min @Babs thank you all so so much for the help!!! its got 15 of talc in in it, the majority is om4. Do any of you recommend any resources (already know about digital fire) that can help with tinkering with clay body formation? I understand some of the ballet of these materials in glazes, but absolutely none of the waltz that is clay body formation. I would love to take the Katz class on this, but am p*ss poor. The recipe I'm using is from an old chappelle book, so I'm not sure about posting it here because I don't want the copyright gods to smite me... but it is a throwing body and im firing it to cone 04 and its vitreous! l I really want to mix my own clay as I live in the middle of nowhere and shipping it out here is often more expensive than the clay itself. I appreciate you all and your kind help! Quote Link to comment Share on other sites More sharing options...
Min Posted September 10, 2023 Report Share Posted September 10, 2023 (edited) It’s okay to post a recipe. edit: I asked about recipes and copyright when I started as a mod, was told by admin recipes are considered as a list of materials therefore doesn’t break copyright to post them. Edited September 10, 2023 by Min Callie Beller Diesel 1 Quote Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted September 11, 2023 Report Share Posted September 11, 2023 Just an addition to Min’s comment, as we’ve been having copyright discussions in relation to other things. You can type out the recipe, and you should give proper accreditation, but you shouldn’t post photos of the book page it’s on. Min and Kelly in AK 2 Quote Link to comment Share on other sites More sharing options...
neilestrick Posted September 11, 2023 Report Share Posted September 11, 2023 Definitely try C&C. I prefer it over OM4 in terms of feel and workability. Quote Link to comment Share on other sites More sharing options...
oldlady Posted September 12, 2023 Report Share Posted September 12, 2023 yes, c&c, definitely, used it for years. it is white and stays that way. Quote Link to comment Share on other sites More sharing options...
Retxy Posted September 13, 2023 Author Report Share Posted September 13, 2023 Oooh thanks @Min for the copyright info!! @neilestrick To sub c&c in a recipe do I need to juggle the chemistry of the new body in glazy the way I would for a glaze to make them as similar as possible? Is that a good rule of thumb for experimenting with clay body formulas? Thanks!! D Quote Link to comment Share on other sites More sharing options...
Min Posted September 13, 2023 Report Share Posted September 13, 2023 Yes, I would. Chem is different between the two, OM4 has about double the KNaO and since you have a vitrified body and the ball clay makes up a significant part of the recipe it probably does make a difference. Other thing is how the clay actually feels, if it gets too sticky sub part of it with a white firing kaolin. It will help the pots dry faster too. Quote Link to comment Share on other sites More sharing options...
Retxy Posted September 18, 2023 Author Report Share Posted September 18, 2023 Thank you so much everyone for your help!! Quote Link to comment Share on other sites More sharing options...
Retxy Posted September 18, 2023 Author Report Share Posted September 18, 2023 On 9/13/2023 at 12:25 PM, Min said: Yes, I would. Chem is different between the two, OM4 has about double the KNaO and since you have a vitrified body and the ball clay makes up a significant part of the recipe it probably does make a difference. Other thing is how the clay actually feels, if it gets too sticky sub part of it with a white firing kaolin. It will help the pots dry faster too. Min I will and thank you for this awesome advice. I'm super pumped, feel like knowing you can play with clay body chemistry in glazy is going to make a difference. Can't wait to see what kind of explosions I cause bwahahaha Quote Link to comment Share on other sites More sharing options...
Min Posted September 18, 2023 Report Share Posted September 18, 2023 Glaze calc software is for glazes although some functions of it, like oxide amounts can be useful. What is still important is to know the qualities of the materials. Talc for example is good at bringing absorption down if just a few percent are used at midrange but when used at high amounts it acts as a filler. Also, COE figures are useless as clay is not a glassy matrix. Magnolia Mud Research 1 Quote Link to comment Share on other sites More sharing options...
glazenerd Posted October 5, 2023 Report Share Posted October 5, 2023 Sorry for the long step away: had eye surgery and just got released. C&C ball clay is 35-40% more plastic than OM4. So if the recipe calls for 25% OM4, then 15% C&C will have close to the same plasticity levels. You can just substitute the remaining 10% with clay. Tom Kelly in AK 1 Quote Link to comment Share on other sites More sharing options...
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