Will 20ºC matter when single firing?

[Tam U.]

Hello from Portugal! 

I've been trying to find an answer to my very specific question over the past week but I don't seem to find anything useful. I've come across the usual recommendation on Steven Hill's single firing but it still doesn't seem to apply to my predicament.

So basically, I'm using just one type of clay body with the manufacturer specifically writing the following -- MIDFIRE: 1000 - 1200ºC, Dense at: 1150ºC.

I plan to use my BOTZ Steinzeug Stoneware Glaze, which BOTZ marked for Cone 8-9 and a range of 1220ºC - 1280ºC (and by plan I mean it's the only glaze I have at the moment)

With my limited knowledge, I'm aware that I should not fire the clay higher than its maximum rated Cone or else disaster!

So, considering the above, would it be possible for me to just fire at 1200ºC as the maximum temp? Or will the glaze not mature since I'm off by 20ºC? Can I compensate by soaking longer instead?

I'm using a Bentrup TC66 so I'm limited to 2 segments with only 1 ramp soak on the second segment.

 

I'm sorry if this is a stupid question but I think I'm running out of search words for Google! 

Thank you so much for your input.

 

--Tam

 

[Min]

There is usually a little wiggle room in clay firing temperatures, you could try going to 1200C and soaking for 15 minutes or so. I think you are going to just have to try it and see.

I looked up the BOTZ Steinzeug Stoneware Glaze and from what I read they recommend firing to 1250C plus a 30 minute soak. What they do have is what looks like a highly fluxed product called BOTZ 29020  that you can put over your BOTZ glaze to lower the firing temperature of it down to 1150C. It will increase the likelihood of glaze crazing though. Link to it here. 

Welcome to the forum!

[Tam U.]

Thank you Min, and also for the link.

I will probably do 2 firings: one at 1200C, and one at 1150C once I've acquired the BOTZ 29020.