Once Firing

[Kaitlyn Miller]

Has anyone had success once firing Bmix with a clear glaze over top? I'm about to teach some clay workshops and if I could figure out a way to just fire the pieces once, it would be a miracle! Thanks!

Kaitlyn

[Bill Kielb]

I haven’t once fired in a long time but years back I tried each of my clays. Stoneware, Bmix and porcelain. They all reacted fine with my glazes. My extent of experimentation was to make sure I used a very standard bisque schedule but fire to desired finish cone temperature.. All of those clays went through bisque temperature in the usual amount of time then went to glaze temperature with no issues having thoroughly off gassed by cone 04 (my bisque temp). There are folks here who once fire always and likely will weigh in with any tricks.

I think half the battle is application / decoration and the other half would be to fire the same speed as your standard bisque schedule to make sure the clay off gasses as usual well below your desired finish cone. Easy to run a test of several combinations just to be reasonably sure.

We were pretty lazy at the time so basically used the cone 04 bisque auto fire but simply changed it to finish at cone 6.

Edited March 9, 2023 by Bill Kielb

[oldlady]

i am one of the folks happy to be  once firing.   i have not had any problems that could not be attributed to my own errors.   very few over many years,  maybe once a year one piece .   i am absolutely NOT adjusting any firing.   i have an L&L programmable kiln that i only fire to the standard cone 6 slow glaze.  i do not know more than the manufacturer so i stick to simple.  it works.   i have one  wonderful white clay, highwater little loafers that works on the wheel and as my favorite, slab serving pieces.    

my own errors have been twice i did not fully dry a piece that had an overlap.   the design was new and i was just too impatient.  so one thing blew up.  it did hit a few other pieces but everything else survived.

i never wedge, clay straight out of the bag is much more compacted than anything these old hands could wedge.   to make a slab, i smash the slice of clay on the floor stretching it and compressing it at the same time.   no bubbles and i never make anything as thick as the 1/4 inch beginners are told is necessary.   why?

i have refired pieces for changing  a color or adding a second color detail and to adjust some pieces that did not get a deep enough sprayed layer.   in any load there might be newly made greenware,   totally dry.   a piece that is glazed and has gone to cone 6 with insufficient color,  or a glazed piece whose test on a smaller piece made it seem good color that i recovered in something else.

have used many different glazes without problems.   maybe being self taught has freed my head of the restrictions some people think are necessary and i have never considered myself an ARTIST so i don't look for DIFFERENT.

try it, you might like it.

[LeeU]

Oldlady-you turned me on to single fire (thank you) and I did my homework (beginning w/Stephen Hill) and that's all I do now-never bisque. I also have an L&L EZ  & usually program slow glaze & often slow cool (depending).  In my library I have a copy of Fran Tristram's Single Firing book that I got--signed--from Marcia Selsor...that was fun!  I try to avoid wedging also and use the cut & slam method most of the time.  Never any glaze problems-I use commercial ones. I am enjoying doing calculated/deliberate refires, to get "artistically different" final surface treatments. I have used clear glaze on B-Mix in single fire, but I just wasn't a fan of the B-Mix compared to some other bodies--but the glaze looked great.

[Kelly in AK]

A lot of encouragement here. I could wax on about how single-fire is how most glazed pots ever produced were fired and how forgiving commercial clay and glazes are to “off label” techniques. I only caution you to do it for yourself at least once before trying in a workshop setting.

To further embolden you, every now and then one of my students glazes a piece of greenware (Because they don’t listen! Haha!). I fire them with the rest and haven’t had a problem. 

[Kaitlyn Miller]

Fantastic. Thank you all for your experience and advice! I'm going to give it a test run and see what happens. I mix my own clear glaze, so we'll see!

[oldlady]

my advice for that firing is to try as much variety as you can fit into your kiln, your schedule and your store of recipes,  may have an interesting firing with many results.  

edit   just realized i forgot to include this .    if you are a worrier, try to do your test firing on one shelf of your kiln, you are probably not going to have any problems that affect anything else on a different shelf.   that is only during the first test as i suggest in the first sentence above.   later, you will have learned the difference between dry greenware and a piece not totally dry.   experiment with application, dipping times, brushing, thicker brushing, whatever way you normally work.  

Edited March 10, 2023 by oldlady

[Kaitlyn Miller]

Thank you all!!! I had very good success with my tests!! I fired Bmix greenware with a clear glaze that I made, and the results were exactly the same as the bisqued pieces. I am thrilled!! I'm sure glazing larger pieces may provide a challenge (fragility) but I've got the courage to give it a go again! Thank you all so much! This means I can do a weeklong workshop with kids making a single serving dinnerware set, have them paint the clay in underglazes, and all I have to do is let everything dry, glaze, then fire. ONCE!! Amazing!!

[LeeU]

 

2 hours ago, Kaitlyn Miller said:

paint the clay

Just one little picky thing---please don't teach kids--or anyone, really-- that they are "painting" on clay. They are using glaze, not paint; they are glazing, not painting. There is a difference--a big difference--and it doesn't serve them well to leave the experience without knowing the difference and learning correct terminology.