Babs Posted December 30, 2017 Report Share Posted December 30, 2017 I was tidying up odd pots and decided o try a different glaze. I had a recipe for Nutmeg and so I set forth, did something I NEVER do, ran a running total down side of glaze quantities to see if it was written in percentages..DOn't do this at home. I then multiplied by 10 to get a decent trial for testing..wait for it Nutmeg R.T. Wgt in gms Dolomite 23.30 233 Spod 23.30 46.6 233 called away to help :-(( Frit 3134 6.8 53.4 534 alarm bells OM4 23.30 76.7 767 bigger alarm bells Silica 23.30 100 233 and the additions to colour I was called away again, don't ever be nice, it works against you , came back and re added the tin oxide, I think,.... OM4 threw me, ball clay is what this old lady knows this by and we also have here whiting sold as OMny carb, but I was aware of this so got the right ingredient, feeling pretty pleased with self, would think knowing the total should be 1000g all up...nope, even thought, well that's a lot of frit for a "cheap" glaze.... scraped the bottom of my container getting enough....and that's a lot of ball clay... Anyway, I put it on the inside and top third outside of a single left on the shelf mug., fired it to cone 6 with a fifteen minute hold last night, woke up to be there to see kiln turn off 2.15am,, had to wait a bit, and the penny dropped onto my frontal lobe!!!!!! SO question to you guys with the chemical slant on life, what will the result be? I think the frit:clay went from a 1:3.4ish to 1:1.4sh, not even sure of that on this fine day..... so it will be on my shelf??? When applied it took a while to dry on pot and I was thinking about that too Moral of the story don't run a running tally anywhere near your recipe, put ear muffs on so can't hear other peoples" dramas. Double check your maths Don't be nice. Have a safe New Year oh what do i add to make this right? just joking but for those who like mathematical challenges. Link to comment Share on other sites More sharing options...
glazenerd Posted December 30, 2017 Report Share Posted December 30, 2017 Interesting batch of eutectic soup. Do not have my glaze calculator handy, but from the ingredients somewhere in the satin range. Calcium and magnesium from dolomite, boron from the frit; and iron, titanium, and magnesium from the Om4. Lithium from the Gwalior spod, plus a fair amount of alumina. Om4 holds 35 grams of water per 100 grams to form a pliable ball. Thinned down for glaze, nearly 50 grams per 100 grams of clay. So drying time should have been much longer. Lower expansion I would expect due to lithium, clay, and alumina content. The OM4 is going to produce the color primarily. just label the bucket: " Frankenglaze" little electricity and it will come to life. Link to comment Share on other sites More sharing options...
Mark C. Posted December 30, 2017 Report Share Posted December 30, 2017 The result will be different-thats what I predict Link to comment Share on other sites More sharing options...
C.Banks Posted December 30, 2017 Report Share Posted December 30, 2017 Everything looks within the lmits for Green and Cooper. The boron is a bit high but the alumina is neither too high or too low. The lithium might tip the melt a bit towards runny but my guess is for a happy accident. The silia:alumina ratio suggests, as GN anticipates, a more satin result but the magnesium is insufficent for a proper magnesia matte in my experience. Link to comment Share on other sites More sharing options...
Dick White Posted December 30, 2017 Report Share Posted December 30, 2017 Looking at it in Glazemaster, it should be ok, though different as Mark correctly predicts... The alkali level is higher (.26 now vs. .22), but not out of range. However, now the alkali content is dominated by sodium from the frit vs. lithium from the spod, and this changes the expansion quite a bit so there might be a glaze fit problem. The Si:Al ratio is lower (6.5 now vs 7.2) because of the added clay, but not completely out of range. The big change is in the boron - now .28 vs. .07. That will add some melting and gloss. Let us know how it looks when it comes out of the kiln. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted December 30, 2017 Report Share Posted December 30, 2017 Whoops, I predict, hmm, a lovely clear Link to comment Share on other sites More sharing options...
C.Banks Posted December 30, 2017 Report Share Posted December 30, 2017 This glaze 'adventure' reminds me of something from a Greg Daly book. He has a section on random glazes and how we can learn from odd/unexpected ratios/results. I enjoy trying understand eutectics so the perspectives here are helpful. It might be fun/educational to share a random glaze or two. Link to comment Share on other sites More sharing options...
Babs Posted December 31, 2017 Author Report Share Posted December 31, 2017 yes, random indeed. I have Greg Daly's book and have "randomly" used a few . It's interesting and as long as you use biscuits to save shelves , fun. takes away the fear of playing. Highbridge, the colorants were RIO, Tin and major Yellow Ochre by cones my kiln didn't quite get a touching toe 6 I'll place a pic, in a few mins. Rockhopper, knew there would be a maths freak lurking. Potters come with many obsessions. Thanks. All Link to comment Share on other sites More sharing options...
Babs Posted December 31, 2017 Author Report Share Posted December 31, 2017 High Bridge RIO 1.07 Yel Ochre 3.24 TIn Oxide 4.85 Bentonite 1.94. By the looks I did not double the tin oxide. The photo makes it much more shiny that it appears just sitting on a table. It's actually much more of a blah brown, no interaction with the lower glaze, a Rockingham brown. I'll try again with a batch before going to the 8000g batch though I appreciate the effort spent doing the Maths. I'll go look for an image of Nutmeg first. Link to comment Share on other sites More sharing options...
Mark C. Posted December 31, 2017 Report Share Posted December 31, 2017 Blah brown-it sounds close to nutmeg without the speckles . It could have been much worse-you would need a chisel to remove from kiln-then it may have been a different name than Blah. Link to comment Share on other sites More sharing options...
glazenerd Posted December 31, 2017 Report Share Posted December 31, 2017 Bentonite is redundant with that much OM 4 included. Not sure the tin is all that useful, would be tempted to replace it with titanium. Perhaps a little bleeding would make for a nice touch. Link to comment Share on other sites More sharing options...
Babs Posted December 31, 2017 Author Report Share Posted December 31, 2017 Yip I was smiling so wide my face ached all morning. I was hopeful because of the amount of Ball clay. It was at the side of the top shelf I had visions of it dripping all the way to the bottom. If anything it was a tad underfired. So in the scheme of things, Glazenerd was about the mark. Amazingly i get where you're at, rockhopper, with the maths. will do a test of Nutmeg to see if I really want this glaze, this batch I think is destined to be mixed with a high gloss one which I do not like, just played with randomly.. B Link to comment Share on other sites More sharing options...
Babs Posted December 31, 2017 Author Report Share Posted December 31, 2017 Just now, glazenerd said: Bentonite is redundant with that much OM 4 included. Not sure the tin is all that useful, would be tempted to replace it with titanium. Perhaps a little bleeding would make for a nice touch. Not sure I'll go mixing this again Nerd, but I may add a bit of titanium, why not, she says.., or spray some on in patches. Kiln gods must have been on my side. Link to comment Share on other sites More sharing options...
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