Underglaze over underglaze

[Lynyfred]

Hi.. I'm wondering is it okay to underglaze over underglaze?

I've white underglazed over grey clay and plan to fire it ( as I want I light base) Then I'm thinking of painting underglaze on when it's fired, will this be okay to do? I ran out of time before holidays and pieces were to big to chance taking home. So had to leave them ready to dry out.

Or is it possible to put the coloured underglaze on bone dry over the white? I'm afraid this might be too fragile to handle as I've quite a bit of work to do on them

Using amaco velvet underglaze

Hope that make sense, Thanks

[Roberta12]

2 hours ago, Lynyfred said:

Hi.. I'm wondering is it okay to underglaze over underglaze?

I've white underglazed over grey clay and plan to fire it ( as I want I light base) Then I'm thinking of painting underglaze on when it's fired, will this be okay to do? I ran out of time before holidays and pieces were to big to chance taking home. So had to leave them ready to dry out.

Or is it possible to put the coloured underglaze on bone dry over the white? I'm afraid this might be too fragile to handle as I've quite a bit of work to do on them

Using amaco velvet underglaze

Hope that make sense, Thanks

Welcome to the forum!

Absolutely it's fine to put underglaze on fired underglaze, if that's what you are asking.  I do it all the time.  For instance, you change your mind and want to add some design elements after the piece has been bisqued.    Occasionally you will run into an issue with one UG being a little cranky with layering, but it's not often in my experience.   If I can do all my underglaze work on bone dry, I do. Speeds up my glazing process.  You will have to make the decision as to the fragility of your piece while it's in the bone dry stage.   I mostly use Amaco velvets as well.  But short answer, I use underglaze on bone dry and on bisque.  

Roberta

[neilestrick]

Commercial underglazes can be applied to wet clay, leather hard, bone dry, or bisque, and can be applied over other underglazes at any stage. The thing to watch out for is that some underglazes don't take dipping glazes very well unless they've been bisque fired to burn out all the brushing agents. Test, test, test.

[shawnhar]

I find the opposite to be true for me. I always apply cone 6 clear over my underglazes, and if I bisque fire them 1st, I have a hard time getting the clear to stick, comes out a bit thin.

[Min]

2 hours ago, shawnhar said:

I find the opposite to be true for me. I always apply cone 6 clear over my underglazes, and if I bisque fire them 1st, I have a hard time getting the clear to stick, comes out a bit thin.

I’ve found a few underglazes that need to be bisqued at a lower cone than my usual (05) as they flux too much at that cone to allow a normal glaze layer. If your clay and glaze is okay with a cooler bisque then firing cooler might help. Means a quicker dip in the glaze bucket but that’s easy enough to do.