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crawling glaze ^6

updated sat 25 jan 03


John Tiemann on thu 23 jan 03

I have begun experimenting with three different ^6 Ox. crawling glazes. All crawl beautifully in their own way, however, they are either bright white, or creamy in color. I would like to add colorants to each of these to achieve a crawling glaze that is either blue or green or anything but white/cream.

Can I just add colorants or mason stains to achieve this? Or will colorants or mason stains prevent a glaze from crawling? What colorants or stains work best or should I avoid? In what percentages should I try adding these to the batch? I have tried placing a colored glaze over or under the crawling glazes with mixed results. I want to achieve contrast between the lines created between the crawling glaze and the crawling glaze itself. Are there certain rules to abide by such as gloss under crawl.... gloss over crawl.....matt over crawl....matt under crawl...etc.

I can provide the three recipes if they would be helpful in answering my many questions. Or if anyone has a favorite ^6 ox. crawling glaze that would help in this matter, I would appreciate it.

Like I said, I am just starting with my experiments, but any advice from the experts would be appreciated. Thanks in advance.

John in St. Louis, Missouri...going into below zero temperatures tonight!

Lois Ruben Aronow on fri 24 jan 03

>I have begun experimenting with three different ^6 Ox. crawling glazes.=

I use crawling glaze in my work. I do use them to excess, as you can
see on my web site (I have posted new work there). There are so many
different effects you can achieve, from a birch bark effect to lichen
to peeling paint to the almost smallpox looking thing I do. =20

You can indeed use colorants/mason stains. They won't hinder the
crawling effect, but the colors you get won't be anywhere near as true
as if you used them in a regular glaze. Additionally, it has been my
experience that you cannot get blue, as the high amount of magnesium
carbonate used in these glazes sucks out the blue. Cobalt or blue
stain will turn purple. Greens will turn pale yellow. Purples turn
almost white. The best advice I have is to experiment, experiment,
experiment. I'm trying to develop a fritted crawl glaze in order to
achieve the blue, which is my impossible dream. =20

I have used anywhere from 5 to 10% colorant in my crawling glazes, and
have not found huge differences in color intensities. Also, crawling
glaze is extremely sensitive to thickness. Play with the amount of
glaze you apply and see which effect you like. Crawling glaze also
looks VERY different sprayed or brush on than dipped.

the other variable in using a crawling glaze is getting it to stick to
- and stay on - the pot. I have read somewhere about adding treacle
to the mixture, but this just made a big mess for me. Others have
suggested spraying the pot with wood glue. Since I completely cover
my pots in the stuff, these haven't worked for me, but they may work
for you. Careful handling and placing them in the kiln semi-wet has
helped alot. Also BEWARE - the crawling glaze spits like an
orangutan. Get a good kiln wash and be prepared to scrape. I've
always felt it was a small price to pay, but, it is the nature of the

There are many recipes out there. The simplest thing to do is to
start adding percentages of mag carb to your base glaze - 10%, 20%,
30%. It's very light, so you need a huge bowl to measure it out in.
5 lbs of the stuff comes in the same size bucket as 25 lbs of silica.
=46ine Craft Porcelain - New and Updated for 2003!!