Working on Cone 6 Oxidation Glaze Tests. Mostly trying to find a great runny ash glaze that looks like a cone 10 reduction ash glaze. Have found a Val Cushing glaze that is starting to produce very good results. My next round of tests is going to be layering that with various coloring oxide combinations over various combinations of Nutmeg & White Satin Matt combinations sprayed around the bottom of pots to give that wood fired look where there is little or no glaze toward the bottom of the pot.

I should have a new load fired sometime this week. Spraying and loading the kiln a little at a time then have to get out my camera setup to take some photos after that.

What Val Cushing glazeare you using ?
I am trying to get the same effects. So for no luck.

The Val Cushing G4 Cone 6 Ash Glaze I'm using is as follows:

Wood Ash: 50
Gerstley Borate 20
Whiting 12
EPK 8
Silica 10

I'm going to try and post a picture of a bowl using this glaze
and the coloring oxides I used were 1% cobalt carbonate and 6% copper carbonate

This is really a nice Cone 6 oxidation rivulet glaze. My first experiments had some pin holing in the glaze but I think this might have been due to the fact that I was bisque firing only to cone 010. I am doing a new kiln load using this glaze and come other coloring oxide combinations this week and I have bisque fired almost all those new pieces to cone 04 so there is a better chance that any organics that might have contributed to the pinholing will be fired out of the bisqued pieces.

1. Recipe correct
2. Leave bottom peephole open about 1/8 of its area and if your kiln doesn't have a vent hole in the top of the lid, then leave the lid cracked open about an eighth of an inch with a wad of clay.

At 11:46pm on January 4, 2010, Brian Dean said… George Love some of your glazes. I particularly like the C Harris Temoku Breaking Red Glaze. Can you confirm this is the recipe for that?

C Harris Temoku Cone: 6
Color: red brown black
Firing: Oxidation Surface: Glossy

27.8 Silica
18.6 Kaolin--EPK
18.6 Nepheline Syenite
9.2 Gerstley Borate--1999
9.2 Dolomite
9.2 Talc
7.4 Bone Ash
100 Total Additives
11.1 Red Iron Oxide
Comments: One hour hold maintained within + or - 10 degrees of 1742 F with plenty of oxygen circulating are the keys to the best red development.

I have a Skutt Electric Kiln with a programmable controller but it does not have a vent. How do you get "plenty of oxigen circulating" in that event?

Thanks,
Brian Dean

I really like your glazes. Beautiful pieces.  I believe you have helped to set a higher standard for me.  Simply gorgeous.

The problem does seem to be the clay body. Apparently proper ventilation through the kiln and plenty of oxygen during the bisque firing is supposed to help, this is something I have not focused on yet.
I only get the pinholes on the surfaces that have the strontium Crystal magic as a base.
The insides of my pots have Steven Hill's red orange glaze all by itself and there are never pinholes there.
On some other forum somebody mentioned that the grog in the clay body could also somehow affect the occurrence of pinholes, where the grog is protruding from the surface such as a trimmed area versus an area that has been compacted and smoothed with a medal rib.
I started considering this possibility this evening because the majority of the pieces that have been ruined by pinholes are on my large bowls, bowls that had been trimmed on the wheel. Most of my mugs and tumblers have very few if any pinholes it's just mainly on the pieces that were trimmed on the wheel pieces that may have a rougher surface because of the trimming.
I would just like to find a nice cone six stoneware body that is totally compatible with the Steven Hill Glazes.
There may be some other gassing reaction that is occurring between the glaze in the clay body during the glaze firing something that apparently does not occur when using porcelain.
Somebody noted that the quick drop in temperature from Cone 6 to 1700° per the Steven Hill firing schedule may not allow those popped blisters to heal ,whereas if the ramp down from cone six were slower than a freefall maybe those blisters would seal over?