In my last post, I mentioned using cardboard tubes as curved molds for slabs of clay. Here’s an example of a vase I made using this technique. I rolled out slabs of clay, then laid them into the half-tubes. Once the clay was stiff enough, I took it out of the tubes to work with it. I found the cardboard tubes to be problematic, though, because the moisture from the clay caused them to lose some curve. So today I decided to make some plaster hump molds. Hump molds are designed to lay slabs of clay over, as opposed to slump molds which allow you to slump a slab of clay inside.

First, I laid slabs of clay into the tubes. Then I put more slabs at the ends and sealed up the cracks with coils of clay, then smoothed it all out to make a nice surface for the plaster. I let those sit until the clay was a little past leather hard, not dry yet, but not quite pliable.

Then I assembled all of the materials I needed. Everything must be within reach when working with plaster. It starts to set quickly so I didn’t want to mix it until I was ready. I measured the water and weighed the plaster - two gallons of water, 22 pounds, 13 ounces of plaster. Then I mixed the plaster and poured it into the molds. Here is a picture of the large mold, then the measured water and plaster, and the molds once the plaster was poured:

Here they are after setting up and being removed from the molds. At this point they are still pretty wet, and have some clay residue left on them. I’ll sponge them off and allow them to dry for a couple of days before I use them.
The finished products were one large and two small half-round molds and a tile mold. One great advantage of using a plaster hump mold is that a slab of clay will dry much faster than another material. The plaster actually pulls water out of the clay. These molds will cut the waiting time down when making handbuilt items.

A quick post before I head off for my day job. I have been crazy productive the past two weekends! Knowing that a show is coming up is a great way to light a fire under this girl. The tally after the weekend: Four very large platters, several bowls, spoon rests, large mugs and some plates. I also made a few slab vases and played around with some new curved forms. Paul had some large cardboard tubes and cut them lengthwise for me, and I laid slabs into them. One of them ended up being a dish (maybe a breadstick dish?) and I am not yet sure of the destiny of the other. I’ve got some cool ideas that I’ll try this weekend, and I’ll post some pictures of what I come up with.

I’ve been potting like a mad woman these past few days. I am happy to report that my unintended extended break didn’t cause me to forget how to make pots! I have been invited to participate in a show in early December (Flagstaff’s First Friday Art Walk), plus was already signed up for the two-day sale in November. I have a fair amount of stuff in stock but need to make a lot more.

On the agenda for the next month: BIG stuff. Fruit bowls, mixing bowls, platters. Also a ton of spoon rests, a bunch of mugs - I’m going with the “mugs for men with big hands” theme, also some sushi sets and chicken roasters. I should have enough for a bisque firing next weekend.

Onward!

The days are getting shorter, which tells me that I’d better get it in gear and make some pots! I was accepted to a two-day juried show the weekend before Thanksgiving. I have a lot of pots for the sale but need to make more! I will spend this weekend throwing a lot of bowls, some pasta plates and maybe some mugs. Maybe I’ll make some spoon rests and wax burners, too.