I’m at your neck AC prt 2
Following my development with the Ancient copper replication, I had another breakthrough. To recap I have decided a few things; Decided is a strong word, maybe more like… Figured out. Firstly the glaze (Ancient copper) is essentially a low end iron crystal glaze. The question was, how do I make a iron crystal glaze? I see almost none in the wild. I do realize Alumina, Zinc, and titanium are the 3 main “Crystal” developers in the glaze world but This felt different. Talked to a glaze buddy of mine and he directed me to an iron line test on digital fire https://digitalfire.com/material/iron+oxide+red . The line test shows a line test between 3-15% iron. If you look at the 13% one you can clearly see some type of crystal formation but none of the others really have for crystals I'm looking for. Same recipe, just different amount of iron. This lead me to think there is either a sweet spot of iron needed to make crystals or its all about the fluidity of the glaze. Fluidity being the ability or the glaze to run. So I did what any self respecting glaze maker would do and did a small line test with low Alumina, high silica, and a good amount of flux + zinc. This test turned out very runny but now I have a good lead in the right direction.
Pic #1 is the newly developed glaze ( I just threw together an ok red, ued iron oxide this time) just to see how runny it would be at base.
Pic #2 the same glaze with 5% zinc. This comes on the heels of reading a article abount zinc at 5% making a glaze more fluid.
pic #3 is the same glaze but with =5% more zinc, so 10% in total. And amazingly I see some crystal formation as well as some amazing color. Now this is a good lead. Reminds me of my greymon glaze but with a small amount of crystal formation. I immediately realize the glaze is too fluid. I just need to tighten up the recipe a little. Less silica, more Alumina, refire.
A small note to any glaze maker in the future. A glaze can only be loaded with so much crud before it needs more energy / heat to complete it’s chemical reaction. Usually what I do when I get my hands on a glaze is try to make it as functional as possible, this means I often take out silica and replace it with flux as silica is in damn near everything. It’s in so many things you can take out quite a bit and the other ingredients will often have enough to carry it. This glaze clearly has too much silica and flux but to balance out the recipe I have to out more stabilizer / Alumina without making the glaze too heavy or so stable I won’t get a good run. Remember the runny is what I want, just not so much that I get no crystals. Most crystal glazes are zinc + high movement with low Alumina.
