Jump to content
Sign in to follow this  
fayechristian

White glaze turning yellow

Recommended Posts

I hope this isn't bad manners but I've just realised this would be better posted in the Clay and Glaze Technical forum but I can't see how to delete this post, so now it's double posted, apologies!

 

 

 

 

Please help

 

I have a white glaze that randomly turns yellow.

 

I can use the same glaze for a whole kiln full of work and some pieces turn out snow white while their neighbour is totally toxic yellow.

 

The recipe is:

 

Potash Feldspar 33

Talc 21

Quartz 16

China Clay 15

Whiting 12

Zinc 3

+ Titanium dixide 3

Tin Oxide

 

On earthstone ES160 special clay

 

I fire to cone 9 in an electric kiln with a ventsure extraction system. I bisc to cone 06 - if that information can be of any help?

 

My own theories have been:

 

Contamination from chrome fumes? but it still happens even when there's not chrome in the kiln. The other glazes I use are iron or copper based.

 

Patches of reduction? but it happens to one pot and not it's neighbour some times and in relatively empty kilns some times too. It also happens in different areas of the kiln.

 

I'm not ruling out thickness of application either but it's not the clay showing through it's a sort of bright toxic yellow fog in the glaze, it's also not as shiny as the white.

 

Help/ideas/theories/general musings welcome

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...

Important Information

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