I built a kiln vent. For ease of construction I am using the bottom peep hole for exhaust instead of drilling holes in the bottom of the kiln. I think the peep hole was to big on its own. I took a hollow peep plug and drilled four holes through the end tip. The kiln vents through these. The end of the vent, 6" expandable aluminum, fits snugly against the side of the kiln. It is held in place with wire from the two plugs above it. This all works great. No odor at all during firing.
Prior to the using the vent my kiln always fired one cone hotter on the top shelf than the bottom. I was thinking the vent would help even out this difference. It hasn't. After two bisque firings, the top shelf is still one cone hotter than the bottom. I am glaze firing today. I have several glazes that are cone 5 only. They will blister at cone 6. So I make sure this glaze is in the bottom shelf only. I put my more flexible glazes in the middle and top.
Question: Could this temp difference simple be an element issue? I have never had to change my elements. At this time I am OK with the temp difference due to the different glaze temps. But in the future what can I do the get more even temps. I want to try some controlled cooling firings. I am worried how these will turn out.
I bought a couple of bags of cone 6 porcelain. I don't remember which clay it is. I threw some pots and am ready to fire.
1. Can I tumble stack the bisque fire? I had read that porcelain needs a special kiln wash. Is that with glaze fire only? With the porcelain pots stick to each other during the firing? can I stack stoneware pots with the porcelain?
2. I made some slip with the porcelain clay. I covered some red stoneware at leather hard with it. I tried to do some decorative finger swipes in the slip. Didn't work well. Do I need to add other ingredients to the slip to get the kind of look I am going for? What are the chances the slip will stay on the pot through the bisque? I had heard not to mix stoneware and porcelain. Why is this? I have read several time of porcelain slip on stoneware...