Tag Archives | Pour Horse

Evolution of molds

Or, “Why There are Fewer Custom Glazes Out There Now”

When I was first learning to glaze, my good friend and mentor Joan Berkwitz generously offered to send me a handful of old Pour Horse production molds. These allowed me to experiment with underglazing without fear of ruining an expensive bisque, which was a godsend. They also allowed me to learn to pour slip and clean greenware with what were some very forgiving molds.

But their true value came when I began to make my own molds. Nothing teaches how molds work like getting castings out – or not getting them out, as the case sometimes was! They also allowed me to see how Joanie solved mold-making problems. Although I rarely make castings from them anymore (some are truly worn out by now), I still use them in this way.

I had a bunch of them out the other day, weighing potential solutions to some of the challenges presented by Elsie, and it struck me that it might be fun to share a visual of just how far mold-making has come in the last decade. I took exploded views of three different mini-scale molds. All three were designed by Joanie, though the production copies of the middle one (Finn) were made here at Blackberry Lane.

This is “Limerick“, which I believe was the second Pour Horse “thumb scale” release following the Shetland mare, “Bressay“. Her mold is only three pieces: right side, left side and the ear hat. (Not only did I learn to pour slip with this mold, but I also learned that you don’t clean a messy mold with a wet sponge. That’s why the one side is discolored!)

The early minis like Limerick were designed with production in mind, so the sculpture was simplified. The hindquarters, for instance, were “diapered”. That is, the whole area between the two legs and under the tail was filled in. Once ceramic producers started getting working with sculptures designed for resin casting – with their detailed fannies, chests and “boy parts” – molds had to have gusset pieces. Turned heads also added mold parts. This is “Finn” with eight pieces: right side, left side, ear hat, head/neck piece, two front gussets and two back gussets.

This is now pretty much the standard mold design for what I think of as an easy piece.

That’s because we now make things like this. This is the three mold set for “Taboo” with a total of thirteen pieces. His three separate molds cast (top to bottom in the picture) his 1) head and tail, 2) one front and one back leg and 3) the rest of his body and legs. There are also numerous small pieces for the undercuts in this mane and tail, all handmade with each new mold. His various pieces are cast and then he is assembled while the greenware is still damp.

Needless to say, there are a lot fewer Taboos (and Vixen, who casts from a similarly complex set of molds) than Limericks out in the world! But each mold is pushing the envelope for what we once thought was possible in earthenware.

Which brings me to Elsie and Oliver. Those are two almost-dry Oliver molds off to the right. He is, by present-day standards, a relatively easy mold. I have high hopes that will allow me to get more Olivers out in the world.

The two molds to the left are copies of Elsie’s tail mold. It takes six pieces to make her tail alone – twice as many as it takes to make a whole Limerick. I’m still designing the mold or molds for the rest of her, so I don’t know what the final piece count will be for her. In many ways her size alone makes her easier to do than the minis, though, so hopefully there won’t be a host of motherless Olivers.

Continue Reading

The mud

After the post earlier this week about plaster, I received an email asking what type of clay I used. The question came at a good time, since I was in the process of mixing a new bucket. Since most of the things I make are tiny, a two-gallon bucket of slip like the one in the picture above usually lasts me about a year.

Like most American ceramists making horse figurines, I cast my pieces in earthenware. British pottery companies like Animal Artistry usually work in bone china. I sometimes glaze bone chinas, particularly those produced by Animal Artistry or Marcherware, but anything cast here at Blackberry Lane is done in earthenware. There are things about glazing bone china that are easier, but bone china production is extremely difficult. Earthenware is much more forgiving. (I also like that the fired clay is a warmer-toned white than the bone china. Since white areas of the horse are usually bare clay, and the underglazes are themselves somewhat transluscent, the color of the clay changes the look of the finished piece.)

White earthenware slip is widely available in the United States, and it comes in seemingly infinite varieties. I use a type based on the old Hagen-Renaker recipe. Hagen-Renaker was a pioneer in the production of high-quality, highly detailed ceramic animals. It was later used at Pour Horse, which is how I first learned about it. Having used other commercially available slip, I can’t imagine using anything else. The formula has an unusually high talc content, which I’m told is why it fires extremely white and retains an amazing amount of detail. Certainly if I cast something in “regular” slip and “good” slip, I can tell by the touch which castings are which.

I should mention that the supplies in the picture aren’t for making the slip from raw ingredients. Since I don’t have the space for the kind of equipment that takes, I purchase it from another potter ready-made. It comes in two-gallon buckets which I use to store it. When I am casting, I keep a working quantity in the pitcher. There is a strainer over the top of the pitcher so I can pour the slip from the bucket to the pitcher without getting any dried bits from the rim.

I also had someone write to me about how hard it was to mix the slip by hand. The slip is suprisingly heavy, and it sometimes thickens after it sits, so mixing with a hand tool would be a fair bit of work. I use a cement mixing attachment that fits into my husband’s cordless drill. (This is why he can never, ever find this particular tool – it’s usually in my studio.) It isn’t in the picture, but I also use a small handheld mixer for whenever I need to remix the slip in the pitcher.

The date on the bucket indicates when the slip was made. In this case, it is five year-old slip. Slip works best when it has aged. Since I fear losing my supplier and having to make my own, I tend to hoard it. I use it so slowly, aging has never been a problem here! That might change, however, when I add the larger pieces to the production line later this year.

As a side note, a friend pointed out that I could set comments on moderation, which would allow me to screen for spam. I am going to do that later today, since I really do prefer to keep them turned on. I am a firm believer that conversations among people often lead to new information, and that doesn’t work as well when the conversation is one-sided. I love talking to folks who read the blog, but I like it even better when readers can also hear one another.

Continue Reading