Jump to content
  • Announcements

    • Jennifer Harnetty

      Moderators needed!   12/08/2017

      Ceramic Arts Network is looking for two new forum moderators for the Clay and Glaze Chemistry and Equipment Use and Repair sections of the Ceramic Arts Network Community Forum. We are looking for somebody who is an active participant (i.e. somebody who participates on a daily basis, or near daily) on the forum. Moderators must be willing to monitor the forum on a daily basis to remove spam, make sure members are adhering to the Forum Terms of Use, and make sure posts are in the appropriate categories. In addition to moderating their primary sections, Moderators must work as a team with other moderators to monitor the areas of the forum that do not have dedicated moderators (Educational Approaches and Resources, Aesthetic Approaches and Philosophy, etc.). Moderators must have a solid understanding of the area of the forum they are going to moderate (i.e. the Clay and Glaze Chemistry moderator must be somebody who mixes, tests, and has a decent understanding of materials). Moderators must be diplomatic communicators, be receptive to others’ ideas, and be able to see things from multiple perspectives. This is a volunteer position that comes with an honorary annual ICAN Gold membership. If you are interested, please send an email outlining your experience and qualifications to jharnetty@ceramics.org.
Sign in to follow this  
High Bridge Pottery

Colouring transparent glaze

Recommended Posts

Before starting off making my own glazes up (as I am short of money and time) I just bought a premixed transparent glaze, with three underglaze/stains. I started with a bit of experimentation mixing different colourants with the transparent glaze.

 

I had success colouring the transparent glaze with the (also bought) underglaze/stain but I tried also using iron oxide. The wet glaze had a nice red tint but when it came out the kiln this morning the iron oxide only seemed to have succeeded in making the thicker parts of the glaze stay transparent and not turn white. The normal transparent glaze where thickest turned white.

 

Any explanation? Also any tips on inventive ways to colour my transparent glaze, I have a few different oxides.

 

Fired to 1240 centigrade after applying to bisque. Stoneware clay

Share this post


Link to post
Share on other sites
Guest JBaymore

Red iron oxide is a powerful "stainer" of the wet base glaze batches. It aways looks like more than it really there.

 

For coloration, it can take quite a bit (percentage of total dry batch weight) of iron oxide to haver a significant coloring effect. So example some tenmoku blacks and saturated iron reds take between 10 and 12% of the total DRY weight of material to get those dark colors. For celadons (on white clay) as little as 1/2% will give a subtle ice blue or light green....... but on stoneware would show little difference from the clear glaze.

 

Are you firing oxidation or reduction?

 

best,

 

.......................john

Share this post


Link to post
Share on other sites

Just oxidation in an electric kiln, that's all I have to use at this moment in time.

 

More iron oxide is probably the key, I added the same amounts of oxide as I did the purchased underglaze/stain. The stain coloured the glaze very well. Shame about my technique at applying the glazes laugh.gif

I seem to have much better results just painting it on instead of dipping or pouring. Always to thick and lots of drips with the latter.

Share this post


Link to post
Share on other sites

As an experiment, before trying it on a student project, I used a black iron oxide stain, and then put an Amaco clear transparent over the top. The project was a sculpture, and the student wanted an antique sculpture look, but also a gloss to it. So, as a precaution I tried layering the two, on a scrap piece of bisqueware I had sitting around. I'm glad I did, because putting the clear on top, caused the black stain to turn dark green.

Share this post


Link to post
Share on other sites

Just oxidation in an electric kiln, that's all I have to use at this moment in time.

 

More iron oxide is probably the key, I added the same amounts of oxide as I did the purchased underglaze/stain. The stain coloured the glaze very well. Shame about my technique at applying the glazes laugh.gif

I seem to have much better results just painting it on instead of dipping or pouring. Always to thick and lots of drips with the latter.

 

 

 

I am coming to England the end of May. We will travel from London to Scotland by train. Where are you from London?

 

Roberta

Share this post


Link to post
Share on other sites

Newcastle upon Tyne, far north of London but if you are traveling to Scotland you will be coming right past laugh.gif Here is a map that I found very quickly map

 

Just google Newcastle upon Tyne and you will find a better map, but I couldn't work out how to link them into this post.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×

Important Information

By using this site, you agree to our Terms of Use.