Refire for better results?

[Tex]

 A piece I fired cone 6 came out too dark.  What might I expect if I reglaze with a lighter shade and refire?  Any suggestions? I’m new to this so this is a learning experience.

thank you

[Pres]

Reglazing is difficult, heat the pot first, and spray on the glaze. You may get some pretty funky effects depending on your choice of glazes. If you use a transparent glaze, the dark glaze underneath will control the new glaze and still be dark. If you use a light opaque glaze over top expect it to break in areas, and to have some running possibly. I would also try to figure why it came out so dark, was it the glaze, or the firing?  Good luck, I have done this in the past, and the chances of the piece improving are about 50/50.

 

 

best,

Pres

[Chilly]

If you don't like it as it is, you might as well chance it.  

I've re-fired stuff successfully, and I've had some mega fails.

 

[liambesaw]

I'll sometimes toss a glazed piece into a bisque firing to see what happens.  I've found quite a few glazes that change drastically being refired just to bisque temps.  Might be worth trying before firing all the way back to cone 6.

[elaine clapper]

Liambesaw, I am curious... if I glaze fire a piece at cone 6 and then refire at cone 04 (my bisque firing), will the surface still be good for dinnerware?  

 

[liambesaw]

2 hours ago, elaine clapper said:

Liambesaw, I am curious... if I glaze fire a piece at cone 6 and then refire at cone 04 (my bisque firing), will the surface still be good for dinnerware?  

 

I'd imagine so, since the glaze doesn't seem to melt, but that's something you'd need to test to verify if you're using toxic ingredients.

It seems to just change oxidation states.   I have a lovely variegated brown that turns bright red when bisqued.  I have a nice titanium and  copper green that is normally translucent green that turns opaque pastel green when bisqued.  

 

[Magnolia Mud Research]

3 hours ago, liambesaw said:

I'd imagine so, since the glaze doesn't seem to melt, but that's something you'd need to test to verify if you're using toxic ingredients.

It seems to just change oxidation states.   I have a lovely variegated brown that turns bright red when bisqued.  I have a nice titanium and  copper green that is normally translucent green that turns opaque pastel green when bisqued.  

I suspect that the change is more likely due to growth of the titanium oxide crystals at the bisque temperature;  the glaze is soft, but not fully melted.  Titanium oxide crystals in a silicate melt (aka glass, glaze) can, and often do , incorporate other metal ions into its structure and with the result being a change the optical characteristics of the overall glaze.  A second firing at bisque temperature is quite similar to the slow controlled cooling steps often call "down firing". 

The glaze elemental composition is a major variable in the changes in the final appearance along with the  temperature profile.  

LT
 

[liambesaw]

37 minutes ago, Magnolia Mud Research said:

I suspect that the change is more likely due to growth of the titanium oxide crystals at the bisque temperature;  the glaze is soft, but not fully melted.  Titanium oxide crystals in a silicate melt (aka glass, glaze) can, and often do , incorporate other metal ions into its structure and with the result being a change the optical characteristics of the overall glaze.  A second firing at bisque temperature is quite similar to the slow controlled cooling steps often call "down firing". 

The glaze elemental composition is a major variable in the changes in the final appearance along with the  temperature profile.  

LT
 

Yeah, for the titanium glaze it will go opaque in places if I slow cool it.  The brown glaze doesn't, however it does get more colorful with browns, greens and blues.  I think it's more due to the several forms of iron oxide, right?  When I retire to bisque it just turns red.