Firing Temp. For Remix

[jte.sears]

The other day I mixed up about 280 pounds of remix from scraps that I found around my classroom. I know for certain that about 250 pounds of the mix is cone 10 stoneware, but about 30 pounds of it is some old terra cotta-type stuff that I think we used to fire to cone 6. Assuming these things are correct, (that I have 250 pounds of cone 10 clay mixed with 30 pounds of cone 6), do you think that I can fire pieces made from this mixture to cone 10, or will I likely have problems with the clay not being able to hold it's shape under the higher temperatures? 

[neilestrick]

Test, test, test...But probably it will work at cone 9 or 10. It also depends on how high the iron content is.

[Mark C.]

You will have to test it for sure

[Marcia Selsor]

Terra Cotta doesn't usually go beyond ^2. YTEST!

Marcia

[glazenerd]

Cone 6 usually has 12-18% more flux than cone 10.        Cone 2 usually has 25-30% more flux than cone 10.

 

I would start my testing at cone 8-9: and do an absorption test for vitrification.

>>Nerd<<

[Mark C.]

Test or toss I say. Toss sees you the testing-Testing May save you the tossing.

The thing here is that clays with different vitrification points should not be mixed unless you are trying to lower or raise the material temps.

Cone 10 clays mix fine

cone 6 clays mix fine

cone 08 clays mix fine.

keep them all separate  fine

Mix them together=test.

[jte.sears]

I understand that adding flux to the clay will lower it's firing temperature, but is there anything that I can add to raise the firing temperature? I'm going to try to set up a test this weekend, we'll see how it goes. 

[Callie Beller Diesel]

Test it first, before you start adding things. It might be ok, especially if the stoneware clay was kind of under fired at the manufacturer's suggested temperature. It may be a nice, mature body (or it might be prone to dunting).

 

The thing that is twigging my curiosity is how homogeneous is that mix? What method did you use to reclaim that amount of clay?

Does your facility sport a Soldner mixer or a mixing pugmill? Are you fond of wedging? (If the latter, I have a job for you )

[jte.sears]

Test it first, before you start adding things. It might be ok, especially if the stoneware clay was kind of under fired at the manufacturer's suggested temperature. It may be a nice, mature body (or it might be prone to dunting).

 

The thing that is twigging my curiosity is how homogeneous is that mix? What method did you use to reclaim that amount of clay?

Does your facility sport a Soldner mixer or a mixing pugmill? Are you fond of wedging? (If the latter, I have a job for you )

Haha yep, I've been wedging for a couple hours every day for about a week now. I've wedged, shuffled, and re-shuffled the mix so many times now that it must be fairly homogeneous. I mixed the dry scraps of the two clays before adding water, and continued to mix throughout the wedging process. It's been a pain, but we don't have a pugmill, and I've got a couple of large projects that I need to get done.