Artisstudio Posted February 11, 2018 Report Share Posted February 11, 2018 Hi Friends! Brand new to the site and this pottery world. I have been playing around with clay and glazes but wanted to try mason stains on my white clay. My question would be, do I need to apply a clear glaze after I fire bisque for the piece to be food safe and functional? Which methods of safety should I take to be able to use the piece in my kitchen? I usually fire bisque at 04 and glaze at 05. Any tips? Link to comment Share on other sites More sharing options...
Up in Smoke Pottery Posted February 11, 2018 Report Share Posted February 11, 2018 Short answer, yes you would still need a place to seal the clay and make it able to hold water. Food safe is another issue depending on the Mason stain some could leach toxins into the clear glaze. What are you hoping to achieve with the Mason stains? Making colored clay or a wash? At earthenware temps you could do numerous things with a product like Mayco's stroke n coat. Link to comment Share on other sites More sharing options...
Artisstudio Posted February 11, 2018 Author Report Share Posted February 11, 2018 Thank you for your answer! I am looking to make mugs and bowls in a nerikomi style so I would be using the stains to male colored clay. Would you happen to know which stains would be toxic or where I can find more info on it? I've been searching the web but cant find a clear answer. Link to comment Share on other sites More sharing options...
Mark C. Posted February 11, 2018 Report Share Posted February 11, 2018 Stains contain colorants-some colorants contain chemicals you do not want to have come into contact if you are drinking said fluids or eating food from that surface. Colors that traditionally have nasty items in them are yellows and oranges -things like cadmium or not good for you.The threshold of toxicity in the USA is different or non existent for many materials. A lot of this has been covered in this forum -use the search function to find it. There has been a lot written here on this and your best resource is the search function in upper right of main page. You will find getting a crystal clear answer is going to be tough. Most folks use a clear glaze over these colorant's to make them safer. The temperature you are firing to will also affect the overall melt and fluxing of various materials-its a complex situation . Link to comment Share on other sites More sharing options...
Up in Smoke Pottery Posted February 11, 2018 Report Share Posted February 11, 2018 You can check with your supplier regarding the specific colors, some have been reformulated over the years. I know my supplier has old versions as well as the new ones. Mason stains website will give you current info, read the msds on each color. As Mark C said use the search function on the forum a visual wealth of information from some very knowledgeable and awesome potters! Link to comment Share on other sites More sharing options...
Min Posted February 11, 2018 Report Share Posted February 11, 2018 Insofar as looking at a covering glaze, it would need to fit your clay body very well, without crazing or degradation. This is harder to do with low fire clay than with mid or high fire. Getting a sample pot tested for leaching would be the only way to know if your pot is safe. If you change glazes or firing schedule, ie fire cooler, then the results would no longer be valid. It costs about 35- to get a pot leach tested for one ingredient, a little more for each subsequent ingredient. I’ve used Brandywine Science Center a few times. If you use any stains with cadmium I would definitely include that ingredient to be tested for. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted February 12, 2018 Report Share Posted February 12, 2018 you should check the mason stain reference codes which tell you what chemicals will and won't work with stains, temperatures, etc http://www.theceramicshop.com/store/content/369/Mason-Stain-Reference-Guide/ Link to comment Share on other sites More sharing options...
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