Monday, September 1

a good day

I had a pretty good firing. Quite a few rejects-many do to a glazing incident that I didn't share. I have this container of wax that has alumina mixed in that I use to glaze my galleries and lid rims which helps keep them from sticking together. Well for many of my pieces, after I glaze the inside, I wax the rim and clean the excess off the outside up to the rim. I get a nice clean edge that way. Well, guess what wax I grabbed that morning to wax the rims? Fortunately I had only done about 10 pieces, and the next morning I held them on the wheel with my Giffin Grip (a nice new use I discovered) and trimmed the waxed rims off and reglazed them. I think there was still this residue of alumina and I got a lot of pitting on those rims. Oh well.

I'll put up some photos of the successful pieces over the next few days-maybe some nice photos as well, as I believe some of the pieces warrant a psuedo-professional photo op before I send them off to my review never to be seen again (they go from the review to one of the gallery shops). This piece is a honey pot that thank god came out nice. I owe this honey pot in trade for a massage that a massues friend (spell) gave me a while back.

I hope I didn't offend too many people with my tool review. It is just my opinion, and I know that doesn't mean it is the correct one, and that there are many ways to approach a situation. It is not my intent to be judgmental of anyone who would use such a tool. It is just my desire to scream loudly from my soapbox on occasion.

6 comments:

cynthia said...

I wasn't offended - and the way I look at it, this is your blog and you can say what you like when you like! :)

Controversy creates discussion and is sure to spark some lively conversation and that's a good thing.

I use an alumina/wax combo too for lids. I'm careful with the application maybe based on advice a former instructor gave me about the danger to glazes of free alumina hydrate floating around in a kiln during firing.

Judy Shreve said...

I love the honey pot - the combination of line & circles (dots) is nice.
I hate doing dumb stuff! I thought the tool review was right on. My real problem with the centering tool is it bypasses some basic fundamentals every (wheel) potter should know.

Ben Stark said...

Glad the firing went well! Look forward to seeing some more pics!

Deborah Woods said...

Thanks Judy and Ben-I really like it a lot too.

Cynthia, thanks for your comment-I needed to be reminded of that.

I am so glad you told me about the free alumina. I had these wierd results on some plates-tons of pitholing which I had not gotten before with the glaze and after I read your comment I ran down to check the bottoms and I had glazed them with the alumina wax. I bet there's a connection.

Linda Starr said...

Hi Deborah, I really love that turquoisey glaze and the dots on the honey pot. Can't wait to see your other pieces. I am confused with what you did with your alumina wax. You waxed the lid rims with the alumina wax to keep them from sticking together and then you waxed the top of the rims again to keep the edges clean? Do you mean you're putting wax over the glaze on the rim edges to keep it from running or to make a smoother edge to the glaze?

Also what are galleries?

I'm wondering how one would keep the free alumina hydrate from floating around in the kiln during firing then? By not putting too much on the lids?

Sorry for all the questions, but I am trying to learn all I can.

Deborah Woods said...

Hi Linda-I don't mind the question. A gallery is the part inside of a jar or teapot that you press down into the pot to make a flat ridge for the lid to sit on inside the pot. Sometimes during firing the lids will get stuck onto the galleries just by the nature of the clay maturing and it can be hard to get them off.

Alumina hydrate is a refractory-meaning that it raises the firing temp. A little trick I learned in school was to mix a little alumina into some wax to use as the wax on your gallery and lid edge, and it really does help the lid separate more easily from the pot. It doesn't necessarily always prevent it, but you won't have to knock the lid so hard to get it to pop off.

What I did, was stupidly use that wax with the alumina and put it on my regular rim (as in the part of the cup you would drink out of-not the gallery or lid edge). For some of my work I like to have a clean, crisp edge where the outside glaze meets the inside glaze, so after I glaze the inside I wax the rim and clean up the glaze that spilled onto the outside, up to the waxed rim,then when I glaze the outside the glaze will only go as far as the wax.

The last thing you want on the glazed rim of a pot is alumina brushed on. The rim would be underfired.

Chemicals can migrate during the firing as they volatize. It's one reason you can get flashing onto pots from other pots. For example, copper I believe is famous for migrating. I once got this pink flashing on the sides of a couple of cups due to the pots they were next to in the kiln. So if I've got all this extra alumina volatizing in my kiln it is reasonable to believe that it could have an effect on my glazes, which I think it did, as I also foolishly used the wax (which had a lot of alumina in it) and waxed the bottoms of a lot of plates and their glazes were really messed up.