Underglaze On Mid-Fire Clay

[Pungogirl]

I'm needing assistance on how to best paint details on a mid-fire clay. I'm fairly new at this, but have a small kiln that I fire ^6 oxidation in. My clay is ^6, but when I fire my details with underglazes, the color fires out. I do see that most of the underglazes say ^06. The pieces I'm referring to are decorational, not functional for eating, so should I be using a low fire clay? Does the mid-fire clay have to be fired to ^6?

[hansen]

Pungogirl: Yes and yes. You need to use low-fire clay and yes cone 6 clay needs to be fired to cone 6.

 

Commercial underglazes work great on lowfire white or you can use an white engobe of some kind to create zones on a pot made with lowfire red and then use the underglaze in those zones. Also you can use raku clay, undergaze, then use a clear or clear crackle glaze and with post-fire reduction the colors stand out strongly.

 

If you really want to paint on mid-fire or high fire post, the product you are looking for is called "overglaze enamel".

In which case you are probably firing glazed porcelain to a high temperature, painting with the overglaze and refiring to a low fire. You can buy all these products at the same place, maybe.

h a n s e n

 

I'm needing assistance on how to best paint details on a mid-fire clay. I'm fairly new at this, but have a small kiln that I fire ^6 oxidation in. My clay is ^6, but when I fire my details with underglazes, the color fires out. I do see that most of the underglazes say ^06. The pieces I'm referring to are decorational, not functional for eating, so should I be using a low fire clay? Does the mid-fire clay have to be fired to ^6?

 

 

 

 

[Pungogirl]

Thank you for your response. I guess I will look for the overglaze enamel since I have so much clay that is ^6. At least I know what to do now!

[hansen]

Pungo: I was at one of those paint-your-own pottery places once upon a time. I was getting a couple of gallons of low-fire casting slip, and happened to notice that they carried over 1000 different products for this type of work. Everything, lusters, overglaze enamels, underglaze, commercial glazes, etc. There really are a lot of products out there if you look for them.

h a n s e n

Thank you for your response. I guess I will look for the overglaze enamel since I have so much clay that is ^6. At least I know what to do now!

 

 

 

 

[Chris Campbell]

Amaco Velvet underglazes can be fired to Cone 6 - many of them go up to Cone 10.

Their web site and catalog have images of how they look at each temperature.

It is a good idea to make up your own test tiles so you know exactly what color you will get with your clay body.

 

You might also have been applying them too thinly ... One coat will sometimes disappear.

 

If you go their website you can see color charts, get details and download a lot of information.

[Deanna@AtlantaClay]

I use Amaco Velvets and Spectrum Underglazes to cone 6 - some are better than others but typically do not disapper. I draw sailor tattoos and use a variety of bright colors on porcelain.

Try applying on leather hard clay and bisque firing to set your colors - maybe your clear glaze is contributing? Make sure you use a zinc-free clear.

[Porcenova]

I mix my own cone 5 underglazes, I use mason stains... I add frit or glaze to the batch to make the colors strong.. like the reds and purple....knox

[Marcia Selsor]

I'm needing assistance on how to best paint details on a mid-fire clay. I'm fairly new at this, but have a small kiln that I fire ^6 oxidation in. My clay is ^6, but when I fire my details with underglazes, the color fires out. I do see that most of the underglazes say ^06. The pieces I'm referring to are decorational, not functional for eating, so should I be using a low fire clay? Does the mid-fire clay have to be fired to ^6?

 

[Marcia Selsor]

I use a base mix of 50/ E.P. Kaolin and 50/Frit 3110 and then add mason stains or metal oxides in whatever percentages needed.

Also, Amaco's Majolica decorating Overglaze colors will fire to ^6. Test them. They work well on porcelains with clear glaze or ^6 majolica glaze.

[JLowes]

Speedball also has a line of underglazes that go Cone 06 to Cone 6. I have found the colors to hold true at Cone 6 on white and tan stonewares; I haven't tried it on other clay colors.

 

John Lowes

Sandy Springs, GA

http:\\wynhillpottery.weebly.com

[Marcia Selsor]

I use a base mix of 50/ E.P. Kaolin and 50/Frit 3110 and then add mason stains or metal oxides in whatever percentages needed.

Also, Amaco's Majolica decorating Overglaze colors will fire to ^6. Test them. They work well on porcelains with clear glaze or ^6 majolica glaze.

 

 

In addition to the above, it is important to read and follow the reference codes provided by the mason stain manufacturer. Some colors will not go above certain temperatures. Some work as glaze colorants only. SOme are finiky about what is in the glaze, such as "can't be used with calcium" or "works best with zinc"

[Guest LGHT]

I think I missed the point where you said you needed to fire to cone 6. If these pieces are decoration only and not used for eating is there a specific reason why your not just firing them to cone 06?? I think most of the commercial painting and decorating products are made for cone 06 and if you use 06 clay they will be fully vitrified and pretty strong. I just don't see the point of trying to find a product that works with cone 6 if there isn't a need to fire to cone 6.

[Marcia Selsor]

I think I missed the point where you said you needed to fire to cone 6. If these pieces are decoration only and not used for eating is there a specific reason why your not just firing them to cone 06?? I think most of the commercial painting and decorating products are made for cone 06 and if you use 06 clay they will be fully vitrified and pretty strong. I just don't see the point of trying to find a product that works with cone 6 if there isn't a need to fire to cone 6.

 

 

Not sure who said that, but you should fire your clay to maturity. Firing ^6 clay to ^ 06 will remain pink bisqueware not very appealing even as decorative. Also it would be very fragile and water absorbent.

Marcia