tag:blogger.com,1999:blog-6574046592294768817.post1919987810382895932..comments2023-11-30T09:42:16.566-05:00Comments on Whynot Pottery Blog: Bare with me or the naked truth about our glazes....cookingwithgashttp://www.blogger.com/profile/11456258592273328486noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-6574046592294768817.post-85428330722989518672009-06-18T12:55:20.385-04:002009-06-18T12:55:20.385-04:00I believe I've narrowed the fault down to an o...I believe I've narrowed the fault down to an overly fine material in the cover glaze. It's and albany/ash glaze and I sieved the ash thru a sixty mesh screen. The glaze underneath has bone ash and magnesium carbonate in it as well as soda spar, flint and kaolin. I've been thru a lot of testing with that glaze because of problems with 3 of the five ingredients. First it was the "free" soda spar that turned out to be finer than 400m . Then it was the bone ash that wouldn't crush well and thus became suspect. (now using synthetic) After that it was the magnesium carbonate that turned out to be at least a third denser than any I had bought previously. It took me almost five months to work through all this just because we don't fire any more often than every 4 or five weeks. I'll get back to ya'll after next firing when I've had a chance to try going back to totally unfiltered ash. It might be a while - I'm building a smaller kiln.<br />MarkMHhttps://www.blogger.com/profile/00183467353061364288noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-65020221346110166902009-06-18T12:54:51.203-04:002009-06-18T12:54:51.203-04:00man, it must be the f##king MOON o something becau...man, it must be the f##king MOON o something because I had some stinky problem pieces in the kiln load I just unloaded....maybe it isn't the glaze but the kiln gods are unhappy!!!!!!!!!!!!!!!!!!!!!!Gary's third pottery bloghttps://www.blogger.com/profile/07113249576164428106noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-5309503832937322402009-06-18T12:51:03.114-04:002009-06-18T12:51:03.114-04:00kinda wonder if the glaze is mixed thoroughly or t...kinda wonder if the glaze is mixed thoroughly or there are clumps of somethingAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-18736998120414001592009-06-18T09:49:28.534-04:002009-06-18T09:49:28.534-04:00sorry for your troubles... diagnosing glaze faults...sorry for your troubles... diagnosing glaze faults is got to be one of the most difficult endeavors because there are so many variables and each potential solution takes so much time and introduces new variables. without knowing and without adding more speculations i would agree that some compound in the glaze has probably changed. i have had trouble with water too before... lime leaching out. good luckAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-58845345414231335042009-06-18T09:04:27.833-04:002009-06-18T09:04:27.833-04:00Ugh. That totally BLOWS! I hope that your detectiv...Ugh. That totally BLOWS! I hope that your detective work pays off and you're able to find out what's going on!<br /><br />In the meantime, I'm with Jay -- I'd buy those seconds! Please don't chuck them in the pond just yet! :)Annapants!https://www.blogger.com/profile/05206078280018922596noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-6090750057882601022009-06-18T08:33:17.041-04:002009-06-18T08:33:17.041-04:00I've had a couple of pieces where the glaze cr...I've had a couple of pieces where the glaze crawled, complicated sgraffito designs on them. This particular glaze seems to crawl unless I raw glaze. Raw glaze, and no crawling. Bisque and glaze, crawling.<br /><br />Very disappointing.<br /><br />Sorry for your losses.<br /><br />MichaelMichael Mahanhttps://www.blogger.com/profile/09178266405071704355noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-7025865483968675072009-06-18T08:19:56.619-04:002009-06-18T08:19:56.619-04:00PS - - I'm old-fashioned and remember when Sea...PS - - I'm old-fashioned and remember when Seagrove potters would sell just about anything that came out of the kiln in one piece - - I would buy those "seconds"!Jayhttp://www.backcountrynotes.comnoreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-11058922937227468732009-06-18T07:55:49.165-04:002009-06-18T07:55:49.165-04:00Meredith, I am so sorry! This is the most frustrat...Meredith, I am so sorry! This is the most frustrating part of being a potter. <br /><br />I agree with Jay that it's probably a chemical in the glaze -- that seems far fetched when it only happened on some of the pots. But because you've determined it's not placement in the kiln, I would look at chemicals first. <br /><br />Have you recently purchased new chemicals? I've been hearing from other potters about the feldspars changing & I know my recent order of talc is grey instead of white. <br /><br />I sure hope you determine what's going on soon. Your work is so wonderful!Judy Shrevehttps://www.blogger.com/profile/13817638135856406785noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-69111623176098460842009-06-18T00:15:24.406-04:002009-06-18T00:15:24.406-04:00I had problems with a glaze I'd used for years...I had problems with a glaze I'd used for years, mixed exactly the same as always. The problem turned out to be the water - the chemical changes in the tap water I used to mix it up when they started adding flouride to the water supply acted with the glaze to ruin a perfect mixture that had worked for years. I now only mix my glazes with distilled water. It's expensive when mixing a large batch, but much less trouble than ruined pots and all of the disappointment and time trying to reduce all the other variables to fix the glaze. I'm so sorry for your disappointment!Juliahttps://www.blogger.com/profile/08077677066902349111noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-11116404024389557992009-06-17T22:20:32.693-04:002009-06-17T22:20:32.693-04:00From the pictures it looks as if there is a proble...From the pictures it looks as if there is a problem with the bisque, because there are such large crawled areas. Maybe the bisque is developing areas that are not sufficiently porous. <br /><br />Assuming that you are confident of the bisque and that you are not seeing drying cracks on the glazed ware before firing - - if nothing else has changed, there may have been a change in the composition or preparation of one of the materials going into the glaze. If something is milled finer than it used to be, that can cause crawling. It is rare to see a glaze high in iron oxide crawl due to shrinking or cracking; iron oxide glazes usually apply very well. Since the color of the glaze is changing - - too muddy - - I suggest looking first at the whiting or other calcium carbonate source in the glaze, since calcium has a tendency to bleach the color out of iron oxide.Jayhttp://www.backcountrynotes.comnoreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-79743391272439611512009-06-17T21:48:36.296-04:002009-06-17T21:48:36.296-04:00It's great to have discovered this blog and th...It's great to have discovered this blog and the forms on this post are just gorgeous. Hope you find out what you want to know about the glazes; sounds so frustrating!Amyhttps://www.blogger.com/profile/14113529511743405120noreply@blogger.comtag:blogger.com,1999:blog-6574046592294768817.post-32414770294811628942009-06-17T20:53:40.738-04:002009-06-17T20:53:40.738-04:00BUMMER.BUMMER.Shortstuffhttps://www.blogger.com/profile/14167435548266949958noreply@blogger.com