It's been 28 years in the making. Finally I've begun producing some crystalline glazed ceramics. It's like a long term dream come true for me. See http://www.puttgarden.com/crystal/2007/Page.html
Not to sound like someone at the Oscars accepting an Academy Award but I'd like to thank Fara Shimbo, William Melstrom, Jon Price, Jesse Hull, Dick White, Bill Schran, Bill Boyd, John Tilton and Avi Harriman (to mention a few) for your help over the many months as I have tried to sort out where to start.
I'll tell you that while I was getting setup I had butterflies. It's been a long time since I made anything. When I considered it's a new era, my raw materials are all different and I've been out of it for so long I wasn't sure anything would happen. When I opened the kiln lid after the first firing my eyes had to be as large as dinner plates.
I'd like to know if I can get some input on my progress and future direction from Forum readers.
1) Regarding the results from firing #1, is it typical that the higher the glaze loading the less the tendancy to form crystals?
2) Regarding the nickel containing piece from the fourth firing is 4% nickel carbonate too high a loading? Do I need to fire at a higher temperature?
3) What do you think about the streaks, which I think are as a result on not using a sieve? Nice? Poor craftsmanship?
4) I was thinking of continuing to investigate the colors obtained by using differing amounts of oxides. Also I thought I'd mix together the leftovers from my 100 gram test batches to see what I get. Can anyone recommend mixtures of these colorant to get dramatic effects?
5) What do you think so far? See any obvious things screaming for attention?

Avril Farley 1-23-07

Hi Phil, nice early results, but I cannot stress too much the importance of record keeping so that you can replicate the oxide combinations and firing programmes you really like. Even the weather makes a difference (think cooling rates etc). I don't like streaks much, but that is a personal opinion. All my glazes get seived first through 100 mesh then 80 mesh. I very rarely use the coloured glaze inside my vase shaped pots. I use the base glaze only, thinned out a bit more and poured into and fast out of the pot. This is allowed to dry out overnight before I brush on the outer coat, and also paint a little thin layer onto the internal foot ring to ensure waterproofness.

As to oxide quantities, I find that amounts of oxide totalling more than 8% of the total volume is the absolute maximum. However, I combine up to 5 oxides in some glazes in minute quantities to get various shades of subtlty.

I see from the growth rings shown in the picture encased in your posting that you have in fact (inadvertantly?)started experimenting with temperature fluctuation in the cooling. It took me a long long time to find the right program for my glaze base, but you can start by raising and lowering the hold temperature by 10 -20 degrees centigrade at 15 minute intervals during the cooling period.

I really dislike the nickel, it doesn't work well with titanium.

That's my pennyworth, enjoy experimenting, that is my favourite part of this whole tantalising discipline. Best wishes Avril from the Forest UK currently in Australia.

Terry Fallon 1-23-07

Hi Phil

I’m a newbie my self, it’s a great feeling to see your first crystals isn’t.
I’ll add my two cents worth.

#1 is it typical that the higher the glaze loading the less the tendency to form crystals?
( I say yes the thicker the glaze the fewer crystals. But some recipes produce more, and some less.
temp, coloring oxide, smoothness of you body, also play a big roll in number of crystals.)

#2 Regarding nickel containing pieces is 4% nickel carbonate too high?
( if you like the results who am I to say it’s to much.) it’s a little much for me

#2a Do I need to fire at a higher temperature when using nickel?
(If I use a base with iron and the same base with nickel the one with nickel will need to be just a bit hotter )

#3 What do you think about the streaks?
( I have never look at a piece with streaks and said to my self what lovely streaks )

#4 I was thinking of using differing amounts of oxides. thought I'd mix together the leftovers from my test batches to see what I get. Can anyone recommend mixtures of these colorant to get dramatic effects?
( with more then 5 colorant oxides I get mud, but maybe you won’t. you will learn more by trying than if you don’t. and then you can try the rest of your life to repeat your success. )

#4a recommend mixtures to get dramatic effects,
( I recommend all of them, and remember some fluxes have an effect on color too such as Lithium, Carbonates and oxide can act quite different as in Copper Oxide, and Copper Carbonate )

#5 What do I think so far? Do I see any obvious things screaming out?
( I think it’s great that the crystal bug has bitten yet another one. Obvious things, you need all new equipment and lots of it, and more time in the day to get to all the things you want to try next.

terry fallon

Jesse Hull 1-25-07

I like the growth ring pattern in the Nickel glaze especially. Glad to see you're enjoying yourself.

> 1) Regarding the results from firing #1, is it typical that the higher the glaze loading the less the tendency to form crystals?
*- The answer depends on the individual glaze makeup and the firing.

> 2) Regarding the nickel containing piece from the fourth firing is 4% nickel carbonate too high a loading? Do I need to fire at a higher temperature?
*- I use 2-3% nickel OXIDE, so 4% NiCO3 doesn't sound like too much. I sometimes give Nickel-bearing glazes a few extra minutes to soak at peak temp.

> 3) What do you think about the streaks, which I think are as a result of not using a sieve? Nice? Poor craftsmanship?
*- Play with it... My opinion?: Poor craftsmanship is a by-product of early practice and a DECISION in later practice. Good craftsmanship is the reason for practice both early and late.

> 4) I was thinking of continuing to investigate the colors obtained by using differing amounts of oxides. Also I thought I'd mix together the leftovers from my 100 gram test batches to see what I get. Can anyone recommend mixtures of these colorant to get dramatic effects?
*-When I was in school, I often got told not to waste my time combining glazes I'd mixed up already. They told me it seemed like a last minute attempt usually done by beginners, with no way of referencing the data for future use.
This would be true if you were just walking over to the sink and adding water. But if you measure the amount of H2O you're adding to the weight of the glaze (including colorants/additions), you can figure out how much weight = how many milliliters. Then you can mix the correct proportions of the already liquefied (and wet-sieved) single tests that come out of the kiln favorably and still keep accurate notes for reproducing them at the same time.
This is a new handle on an old idea. Many test by measuring liquid glaze, but by "cascading" it, you further allow for more prolific results. Instead of weighing out test after test, begin with a basic idea, -put 10-20 individually mixed glaze tests in with a firing, and the remainder of your hydrated tests in tightly sealed containers (don't leave them for more than a few days). Make sure that you don't alter the firing, then take the ones that you like from that first run and mix them together in a bi- tri- or quadraxial format. I usually get several more nice ones without having to go back to the weight scale. Sometimes, I'll mix the last combined glazes together for further firings. The variations and visual complexity gain momentum faster when you're working with different glaze bases (feldspathic, fritted, etc.) as opposed to just altering colorants and modifiers.


~jesse.
 

Avi Harriman 1-25-07

Phil,
A few thoughts and comments:

First off congratulations on a great first group of firings. I thought you got great results and you put a lot of effort in the process.

Comments:

#9 is the interaction of the Titanium in the Rutile and the Nickel. Ask Fara.... Puke Green and no or few crystals. Take the Rutile out of the base glaze and use it as a a colorant if you need/want it. I would add pure Titanium Dioxide except when you want the deep blues of Nickel. That being said William gets good results over-spraying Nickel on Titanium.

Th rest of the colors are what I would expect from the oxides you used. Keep playing with different percentages and doing over/unders. You will be amazed.

As to the settling problem with Cobalt. Cobalt will settle into cement if you turn away to sneeze. Mix it vigorously every time you use it and between pots as well. I have started to add Epsom Salt to my glazes and that seems to keep them from settling. Some are concerned about its effect on the color of the glaze but I have not had a problem

As to the issue of EPK vs Alumina I switched because the EPK mixture separated better after firing. I get almost 100% clean separations with just a small tap of a hammer or the application of a small torch. I used to get separation anxiety and have a lot of grinding after every firing before I switched. I did start using a stronger glue (wood glue) with the EPK and that helped the premature separation.

I always run my glazes through a 80 or 100 mesh sieve after I mix them from raw materials. I then mix them again for 10 or 15 minutes with a bench drill press.

All in all you done good..... Be Happy

Avi