jdedini Posted December 21, 2020 Report Share Posted December 21, 2020 Hey Everyone, This past week I made my first attempt at mixing a 4321 Glaze both in clear and one with 8% Iron Oxide for a Temmoku. The glaze dipped on fairly thick but not as much so as other glazes in my rotation. My cone 10 gas firing results ended up being quite strange. The glaze seemed to crawl to the extreme but the glazes look fine otherwise. Would anyone have any insight as to how to fix this? Thanks! Link to comment Share on other sites More sharing options...
jdedini Posted December 21, 2020 Author Report Share Posted December 21, 2020 I forgot to add, this was a once fire/raw glaze firing. Link to comment Share on other sites More sharing options...
Sorcery Posted December 21, 2020 Report Share Posted December 21, 2020 What's the 4321 411? I have crawling with Dolomite Glazes. Reckon it's the magnesium, add something to do with single firing...I single fire. Maybe it's negative charges between materials. Dunno. Sorce Link to comment Share on other sites More sharing options...
jdedini Posted December 21, 2020 Author Report Share Posted December 21, 2020 Sorry, should have specified Potash Feldspar 40 Silica 30 Whiting 20 EPK Florida Kaolin 10 Link to comment Share on other sites More sharing options...
liambesaw Posted December 21, 2020 Report Share Posted December 21, 2020 I'm going to guess the clay shrunk too much during the once firing, and the glaze cracked off. There are no plastic ingredients in your glaze recipe, so it won't shrink like a clay body will in firing. That's what my suspicion is, do you know if this glaze is known for being once-firable? Some folks add 2% bentonite to their glazes when formulating for once firing, it could be something to try, especially since there is only 10% clay in your recipe Link to comment Share on other sites More sharing options...
Bill Kielb Posted December 21, 2020 Report Share Posted December 21, 2020 I like Liam’s thought although looking at the fired result, not so great either. The 4,3,2,1 I have seen in the last few years was neph sy based. Not sure it would function in a once fire environment actually and what the actual schedule was for your previous firing but the final melt does not look the best in the pictures.( ignoring the crawling of course) Link to comment Share on other sites More sharing options...
Min Posted December 21, 2020 Report Share Posted December 21, 2020 Leach's 4321 has been around for ages with spar not nepheline syenite, I don't think that's an issue. @jdedini did you measure the specific gravity of the glaze before using it? I'm wondering if you just have it with too high a specific gravity. You mentioned the glaze was fairly thick, with only 10 clay it shouldn't look fairly thick. However the iron in the one version of it can cause the glaze to appear thicker than it actually is, iron tends to gel a glaze somewhat, after sitting for a few weeks this tendency diminishes as some of the solubles in the glaze help to deflocculate it. Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted December 21, 2020 Report Share Posted December 21, 2020 I used to work extensively with 4321 base as a celadon when I was still firing at cone ten. While it makes a lovely celadon when you add 3% yellow ochre and a bit of tin, it's missing something that brings out good iron response if you want a tenmoku. I have alternate recipes for that if you want. It's sensitive to the materials used to make it, and changes in the clay and the feldspar will alter your colour response. It's a dreadful clear on stoneware. I always made it with Custer feldspar and EPK and would have not thought to use Neph Sye. It fits stoneware better than porcelain, I found. It works fantastic on bisque, and I never had any crawling, but I did notice it was sensitive to application thickness. This was the glaze I learned about the proper use of Epsom salts on. Celadons like to be thick, but not too thick. They have a sweet spot. I have seen this glaze crawl when applied too thickly, but you would have noticed the glaze cracking as it dried when you applied it. I tend to agree with Min about it possibly being a specific gravity issue. Link to comment Share on other sites More sharing options...
jdedini Posted December 21, 2020 Author Report Share Posted December 21, 2020 Thanks everyone! I tested the specific gravity on these glazes and they were at 1.82 - fairly thick. I brought them down to 1.45. I'll give that a shot on my next firing. Link to comment Share on other sites More sharing options...
Sorcery Posted December 22, 2020 Report Share Posted December 22, 2020 16 hours ago, jdedini said: next How do you glaze? I brush but been thinking of spraying. I break everything if trying to pour. Sorce Link to comment Share on other sites More sharing options...
jdedini Posted December 22, 2020 Author Report Share Posted December 22, 2020 4 hours ago, Sorcery said: How do you glaze? I brush but been thinking of spraying. I break everything if trying to pour. Sorce I'm a dipper...I love dipping. Since its raw, I just use my fingers and I don't mind the unglazed spots where my fingers were to add the human element. I've also thought about spraying. I have a mostly unused compressor in the garage I may hook up with the spray gun. Do you dip or brush? Link to comment Share on other sites More sharing options...
Sorcery Posted December 22, 2020 Report Share Posted December 22, 2020 47 minutes ago, jdedini said: you dip or brush? I brush my Rectangle pots. Since I hand build stuff my rounds aren't round and if I pour the inside they break. Reckon a nice even round allows for dipping but my jury is still out. So I brush them too. I been using a local clay as a slip first, bushed on at 141-143 SG, it never...rarely cracks anything and allows a layer for other glazes to soak into. It fires well between 6-10 so it's a mad go to. Just made some new tests with colorants. So pretty dry I don't want to fire em!lol! Added at 5 grams per 100g wet at 143SG. Yellow Ochre, Iron, Copper, Rutile, Blue Mason Stain, and one with whiting. Previous tests prove quite the earthy pallette that always works, and fires seemingly different at every temp and oxygen level combo. With Rutile at cone 7 and a stripe of something else, on Standard 547. It's like a miracle! Sorce Link to comment Share on other sites More sharing options...
jdedini Posted December 22, 2020 Author Report Share Posted December 22, 2020 4 minutes ago, Sorcery said: I brush my Rectangle pots. Since I hand build stuff my rounds aren't round and if I pour the inside they break. Reckon a nice even round allows for dipping but my jury is still out. So I brush them too. I been using a local clay as a slip first, bushed on at 141-143 SG, it never...rarely cracks anything and allows a layer for other glazes to soak into. It fires well between 6-10 so it's a mad go to. Just made some new tests with colorants. So pretty dry I don't want to fire em!lol! It's like a miracle! Sorce Thats VERY cool! Are you raw glazing or brushing onto bisque? Link to comment Share on other sites More sharing options...
Sorcery Posted December 22, 2020 Report Share Posted December 22, 2020 On 12/21/2020 at 12:50 PM, Sorcery said: ..I single fire 1 hour ago, jdedini said: Are you raw glazing I can't not! Besides the time saved, I love not having to look at a bisqued pot. They gross me out! Sorce Link to comment Share on other sites More sharing options...
jdedini Posted December 22, 2020 Author Report Share Posted December 22, 2020 3 minutes ago, Sorcery said: I can't not! Besides the time saved, I love not having to look at a bisqued pot. They gross me out! Sorce Lol! Link to comment Share on other sites More sharing options...
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