Thursday, November 20, 2008
The last easy part
Ceramic horse molds all have the same general format. There are two big side pieces which have the left and right profile views of the horse. Those two pieces form the structure that holds a varying number of inner pieces. Unless the sculpture has ears that are pinned back or are hidden inside the mane, or unless the head is turned just right so that each ear appears in profile (this is true of many Hagen Renaker pieces), there will be a piece that sits atop the poll. And finally there are the inner leg and belly pieces. Because of my family background in textiles and sewing, I tend to refer to this group of pieces as the gusset.
I find that the two side pieces and even the poll piece to be pretty straight-forward. It's the gusset pieces that are the challenge. This time around, I've added a new level of difficulty because I'm going to eventually cut this little guy apart, which will change how I approach those inner pieces. So this second side piece is going to be the last easy part. After that, the project is likely to get interesting because I'll be making it up as I go along! (Perhaps I should have thought about that before I decided to blog this all in real time, huh?)
But I can put off those thoughts for a little while yet, because at this point all I am after is a rubber copy of my little guy. That means the mold I am making for this step can have fewer inner pieces, because everything involved can bend. (Plaster isn't nearly so good in that regard!)
There was something unusual with this side, though. In most molds, the insides of the legs are contained in the gusset pieces. For this piece, however, the one hind leg was pulled back far enough that part of it could appear on the side piece. What stumped me was just how to plane the clay between that part and the other hind leg. The clay needs to hit the mold line at as close to a 90° angle as possible. To keep that angle at the back of that nearest hock, and still have the side piece pull off clean, that inner piece was going to have to have a tiny lip and then slope dramatically, all across a tiny space (1/4").
I haven't done any molds with inner leg pieces included on one of the sides, but I knew Joan had done that with the Okie Rio mold. I had a sample one here, so I looked and sure enough that mold had the same solution - a thin edge to preserve the needed angle against the casting, and then a quick drop. I used to love having some of the old Pour Horse molds because it meant I could glaze a few of those pieces. Now I spend more time studying them than casting from them!
Imp will also require a small inner piece to catch the detail under his tail. These kinds of pieces that don't extend out to the edge of the side pieces don't appear in the master mold, but are made by hand for each individual plaster mold. That's one more thing I can put off until later!
Here my clay mock-ups of the inner pieces is just how I want it, and I've begun to smooth the clay so there are no rough edges between my plaster pieces. (Everything in front of the foreleg has been smoothed, while the area behind it has not.)
The lines where the legs meet the body are where I propose to cut the legs. These will be removed and cast separately, then reattached when the foal is in the greenware stage. There is one other visible mold line near the top of the foal's head. One of the cardinal rules of ceramic mold making is that you do not second-guess and change your mold lines during the claying up. Obviously, I broke that rule! But I knew when I drew that line that I might revise it if it looked like I had it set too far, which I had.
With luck I will finish smoothing these pieces and get the second side poured today. My goal is to have the whole master made by the weekend, and have a rubber original or two by mid-week. That way I can spend the long ride to visit my in-laws thinking about how to tackle the next steps.
at 9:43 AM