Wednesday, September 1, 2010

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.

3 comments:

Spike Pierson said...

This is a great blog. Thanks for all your hard work and the info you give. I am hoping you post again soon. I wish u keep on.

Rayvin said...

Agreed! Specatacular information Lesli! You are really pushing the boundries of the medium!

Lesli Kathman said...

Joan is the one pushing. I'm just following as best I can. :)