Kennedy Posted July 29, 2023 Report Share Posted July 29, 2023 I am a beginning ceramics student at a university. I just finished a number of projects that had the intention of holding water for periods of time, very small. I dipped them in glaze and I have been using low fire clay. I recently noticed that the water is soaking through to the back which is unglazed. This part is hung against a wall. Any ideas of what I might be doing wrong? Any ideas of how to not have to deglaze but solve the problem another way? Quote Link to comment Share on other sites More sharing options...
Hulk Posted July 29, 2023 Report Share Posted July 29, 2023 Hi Kennedy, Welcome to the Forum! Are you glazing the insides (liner glaze)? A good liner glaze should melt well; not craze (crack); come out be smooth and shiny (easy to clean); not cutlery mark (again, smooth and shiny); stand up to wear, tear, acids and alkalis; and not leach colorants. Typically, advice for functional ware includes choosing a clay that has very low absorption when fired to its target cone, around one percent absorption or less. Still, a sound liner glaze, no cracks, no pits or holes, should hold water! Hope that helps. If you are glazing the outside only, then expect water to soak into the clay, saturating the entire piece! The exceptions would include clays that are fully "vitrified" - that do not absorb any water. Can you post images of the liner glaze and the recipe/formula as well? liner glazeLiner glazes (digitalfire.com) Functional glazeFunctional (digitalfire.com) See the links to vitrification and maturity at the bottom of the article. Callie Beller Diesel 1 Quote Link to comment Share on other sites More sharing options...
neilestrick Posted July 29, 2023 Report Share Posted July 29, 2023 Low fire clay remains porous even after firing. If the glaze has any crazing (crackling) in it, then the water can seep through the small cracks in the glaze and soak into the body. Callie Beller Diesel, Babs and Rae Reich 3 Quote Link to comment Share on other sites More sharing options...
PeterH Posted July 29, 2023 Report Share Posted July 29, 2023 Rubbing indian ink (or black felt-tip pen) over a glaze, then wiping it off is a good way of revealing unnoticed cracks in your glaze. See from about 1:49 into this video Quote Link to comment Share on other sites More sharing options...
Babs Posted July 30, 2023 Report Share Posted July 30, 2023 (edited) Wrt @neilestrick point, you can use a slate sealer or other product to seal the surface which contacts the wall . If seepage significant on other surfaces, i.e. dripping moisture to a floor then may have to seal inside of pots as well. Damp clay pots can harbour molds, some folk may be sensitive to this. Sealing the inside should prevent this. Edited July 30, 2023 by Babs PeterH and Rae Reich 2 Quote Link to comment Share on other sites More sharing options...
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