Oxides and Underglazes

[High Bridge Pottery]

Is it better practice to apply oxides and underglazes to leather-hard greenware or bone-dry greenware? I have been doing a little experimentation and currently in the process of purchasing some underglazes and a transparent glaze to go over the top but I am wondering if I need to keep my work in the leather state or if I can just let them completely dry out before applying the underglaze/rawoxide

 

Thank you

Joel

[TJR]

Working on leather hard clay is always more pleasant than working on bone dry. Dry clay is fragile and brittle. Commercial underglazes are designed to fit all states of dryness, so it's really a personal preference. Why don't you try both states and see which you prefer?TJR.

[neilestrick]

My least favorite time to apply underglazes is leather hard- poor coverage and slow drying. I prefer bisque, but will sometimes do bone dry if needed.

[High Bridge Pottery]

Thanks for the help, my reason for using unfired work is so I can apply a transparent glaze over the top once it has been bisque. From reading a few topics on here it seems like a bad idea to try and underglaze and glaze at the same time.

 

If I am going to apply underglaze to a bisque I will then fire again to bisque temp before glazing or are there any temperature shortcuts

[neilestrick]

I apply both underglaze and glaze to bisque with no problem. You don't need to fire between applications.

[perkolator]

since underglaze has a decent clay content it can be used at pretty much any state of dryness. to add a third option for UG application, you can use many of them as "overglazes", where you'd glaze and then apply your color on top - this way you are less likely to smear your UG if you brush glaze on. doesn't work with every color/brand/clay/combo, so test it multiple ways

[Marcia Selsor]

There are recipes for underglazes and / or slips for using onset, dry, leather hard or bisque. Some commercial products have a wide range for use. It is always best to test.

 

Marcia