Clay Studio Notes: 3-17-13

Soy Wax is a Go

I finally got to try the soy wax in the Crock Pot idea that I mentioned in another post. After unloading the bisque kiln and washing off the pots I was ready to wax the bottoms. Previously, this required getting out the wax resist and sponging or brushing it on each pot. This worked well but it was time consuming. While taking a class at the Goshen Clay Guild I noticed that they had an electric skillet which was used to melt paraffin wax which pots were dipped into. Even though it produced an odor and required more caution, it cut down on the time required to wax the bottoms. Then as I was researching this idea further, I read on the Ceramic Arts Daily Forum that some potters use soy wax and crock pots. So I decided to give it a try.

I dumped enough soy wax flakes in the Crock Pot to cover the bottom and cranked it up to High. After a few minutes the wax started melting and soon it was a clear liquid. There was a slight odor but not as bad as the paraffin. Make sure you are in a well ventilated area if you are melting wax! I dipped my pots in and set them upside down on the table until the wax cooled. As the wax dried I realized that it wasn’t working exactly as I hoped. It was too thick and it started cracking which allowed it to flake off if I pushed on it. I thought the reason was because the coolness of the pot was making the wax cool and harden too fast. So I tried a couple things. First I warmed up one pot bottom with a heater. This allowed the wax to go on in a nice smooth, thin coat. But when I turned it over to let it dry the wax ran down the pot. So then I tried leaving each pot in the wax for a few extra seconds. I still got the same smooth coat but it was a little thicker. It probably would have run down the pot but I just held each one upright for a while until the wax had cooled enough. Next time I might try putting them on wax paper to dry right-side up.

All Rutiles Are Not Created Equal

While showing off pots from my last kiln load of pots I touched on a small oversight concerning my Bone White glaze. When I mixed the test batches I used Rutile that I had obtained a while ago from a Laguna distributor. It was labeled “Rutile” and it seemed to be just fine and the Bone White glaze that I was mixing came out just fine. The problem was that I only had one pound of it. So I ordered a few pounds from US Pigment and mixed up a larger batch to dip and pour. When I pulled the pots out of the kiln with the new batch my Bone White was more of a tan/yellow (see the picture for the difference). Not what I was expecting. I also realized that the brown glazes that I mixed also seemed to have a yellow tint compared to the test tiles.

I had read that Rutile contained iron but since my first bag of “rutile” seemed to have an incidental amount I thought the stuff from US Pigment would be the same. Apparently not according to my results. Then I noticed that US Pigment also offered Rutile Light and Titanium Dioxide so I sent them an email asking about the differences. Here is what I learned:

Rutile is Titanium Dioxide with some iron oxide which changes the color, brown and buff. Use pure titanium dioxide and you will not see the yellowish white but it will be pure white.

Rutile light is almost 98%+ titanium Dioxide.

Thanks to Syed and US Pigment for the information. Maybe the Rutile I had at first was actually what US Pigment would consider Rutile Light. I just ordered some more chemicals from US Pigment and Bailey Pottery. I ordered some extra Titanium Dioxide so I won’t have the iron from the Rutile goofing up my glazes.

Next post should be about what’s cooking in the studio. Thanks for reading.