Samantha.Weber Posted March 20, 2012 Report Share Posted March 20, 2012 Hello! I am pretty new to the firing process. By new I mean that I have fired my kiln a total of 4 times. I bought 4 different glazes that are all meant to come out matt but they all are turning shinny. I fire to cone 6 (mid fire). Also, in the last firing I did there were little holes in the glaze on some of my pieces, what are they from? Any help would be wonderful!!! I am lost! Link to comment Share on other sites More sharing options...
TJR Posted March 20, 2012 Report Share Posted March 20, 2012 The little holes are called pinholing.They come from the following; 1.Firing the kiln too fast so that the glaze does not have time to mature. 2. Dust on the surface of the pot. To solve this you wash the pot[dip in a bucket of water] only if bisqued. Let dry overnight. Then glaze. TJR. Link to comment Share on other sites More sharing options...
Mark C. Posted March 20, 2012 Report Share Posted March 20, 2012 The shiny matt or lack of matt can be a few things- over fired or the clay body its on or a combo-My matts at high temp. look best when fired with a slow glaze melt at maturing temperatures (not to fast) They are dry when under fired-shiny if over fired. What's your firing schedule total in hours? Mark Link to comment Share on other sites More sharing options...
neilestrick Posted March 20, 2012 Report Share Posted March 20, 2012 Slower cooling may help develop mattness. Link to comment Share on other sites More sharing options...
Nelly Posted March 20, 2012 Report Share Posted March 20, 2012 Slower cooling may help develop mattness. Dear All, I think Ron Roy's book said that to develop good strong shiny surfaces to not soak too long at high temperatures and to let the kiln cool rapidly. Also, with pin holing, I think ensuring you have a slow bisque is also helpful. Sometimes not over stirring the glazing and applying with bubbles in the mix can also create these annoying holes. I now stir and then let my glaze sit for a moment or two before dipping. This, along with slower bisque firing is important I think. I don't mean really slow bisquing but rather not going at lightening speed to reach temperature. Nellie Link to comment Share on other sites More sharing options...
neilestrick Posted March 20, 2012 Report Share Posted March 20, 2012 The pinhole issue is a glaze flaw or firing flaw. A well formulated glaze, when fired properly, should not pinhole. The list of possible causes is long, but all can be fixed with some reformulation or with alterations to the firing schedule. If you are not comfortable with reformulating, then you'll have to adjust the firing schedule (slower, hold time). Link to comment Share on other sites More sharing options...
Samantha.Weber Posted March 21, 2012 Author Report Share Posted March 21, 2012 Thank you all for your advice! I will surely use all of your tips!!!! My kiln is very basic, it has two knobs thathave settings for low, med and high. Ithas a kiln sitter, but it doesn’t have a thermometer. My firing schedule for bisque firing is: Bottom low for 12 hours w/ the kiln lid and peepholes open Low and low for 4 hours w/ the kiln lid and peepholes open Med and med for 4 hours shutting the kiln lid and peepholes High and high until the kiln shuts off on its own The schedule for my glaze firing is: Low and low for 4 hours w/ the kiln lid and peepholes open Med and med for 4 hours shutting the kiln lid and peepholes High and high until kiln shuts off on its own Link to comment Share on other sites More sharing options...
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