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Bob Coyle

Member Since 06 Jun 2013
Offline Last Active Feb 24 2015 07:47 PM

Topics I've Started

A Couple Of Cone 05 Glaze Tests

02 July 2014 - 05:51 PM

here are  a couple of glaze tests I ran the other day fired to cone 05 on a stoneware body.

the ramp held at 1150F for 30 min then to 1700F at 500/hr then to shutoff at 125/hr to cone 05 with a kiln sitter.


Sample tiles have a black line drawn on the bisque ware and on top of the glaze to show slump and transparency. Glaze is brushed on with a second coat on the left side.  I added talc to the standard "Jacky" glaze formula to get a little more hide and matte. The G20805 is not modified.


Flecks in the glaze are unmixed pigments, since I just mixed them into the base mix  and did not attempt to completely blend

Jacky Mod 4

Flint                      41.65
Gerstley borate      27.58
Nepheline syenite  10.84
Lithium carbonate   9.51
Talc                       5.66
EPK                      4.76


G2805 Cone 04-06 Matte

Frit 3134             44
Dolomite              8
Kaolin                12
Whiting                8
Silica                  28

Does Any One Else Miss This Nutcase?

11 May 2014 - 11:42 AM

Found these old Soldner adds.... Sexist, politically incorrect,goofy, and (to me) funny as hell.

More Clay, Wood And Metal Sculptures

06 April 2014 - 03:19 PM

Fired up the old forge and beat and hammered some bar stock into a curve. Attached it so it floats in front of a faux pit fired  micacious clay and wood.



Glaze Test Ga28-A Green Breaking Blue

07 March 2014 - 12:13 PM

This glaze was taken from Glazes Cone 6 by M Bailey and modified. It breaks blue where thick on clays containing iron. Really pretty on Laguna speckled buff.

Glaze test on Laguna clay bodies. Fired up to cone 5 with kiln setter shut off. 125 F/hr from 1700F to shutoff.

Comp              %

Neph Sy            68
G.Borate           08
Ball Clay           08
Whiting             05
Silica                04
Rutile               02
Titanium           02
Cobalt Carb      01

Test Of Turquoise Matte Glaze

18 February 2014 - 12:35 PM

Here are some photos of test tiles I made using a recipe taken from the October issue of Ceramics monthly. It makes a pretty nice waxy magnesium matte. It is stable between cone 5 and cone 6 and holds well without sagging with good leveling on the pot. This is important to me because I brush on all my glazes.


This was a straight up run with a shutoff at cone 5 with a kiln setter. the last part of the ramp up to shutoff was 125 F/hr from about 1700F.


The glaze was used on the tree pot which is speckled buff.


Glaze Composition
Ingredient Parts
Frit 3134                       23.40
Flint                              19.80
EPK                             19.10
Custer feldspar (K2O)   14.90
Talc                              11.70
Whiting                         11.10


Cobalt carbonate            0.50
Chrome oxide                0.50
Taken from CM Oct 2000