Friday, October 5, 2012
06 Waste Molds Nº 25
I am going to use the same clay build-up that I used for the arms, for the feet. I changed the registration key. This photo shows one way that the feet could be positioned in the mold, with the ankles up. The problem with this position is that there are those points at the top of the feet, which could trap air, leaving a void in my carving wax casting. I want to avoid that if at all possible. Click on any image to enlarge it.
This is another way the feet can be positioned in the mold, with the bottoms of the feet up. Notice that the feet are also at a slight angle? This way, when the mold fills with carving wax, there should not be any air bubbles trapped at the top.
Having decided to mold the feet in this position, I use the fettling knife to trace around the profile of the feet, as closely as I can. Are you beginning to see a repeated method here? This is the same way I did the molds for the hands and the arms, right?.
These are the outlines of the feet I traced with the fettling knife.
The next thing to do is to use my paring knife to cut out all the clay that is inside the outlines.
I remove the clay-build-up inside the traced lines, all the way down to the plywood support riser. This is because the feet are each 5 cm wide, and the clay build-up is about 3 cm wide.
As I cut away the clay build-up, I place the feet in the cut outs to see if they fit. I keep cutting around the outlines until the feet slide easily into the cut out spaces. Notice that there are some small spaces at places around the oil-clay feet and the clay build-up? I will carefully fill those in with some clay coils and my paring knife. The important thing is to close the spaces so that moulage cannot enter into the spaces when it is poured. At the same time, when I do the second half of the mold, there is not much clay-build-up holding the feet. The clay build-up will come off easily.
This is a side view of the oil-clay feet in the clay build-up, showing the ankles which are pointing towards the bottom of the first half of the mold.
This is a side view of the oil-clay feet in the clay build-up, showing the soles of the feet which are pointing towards the top of the first half of the mold.
The spaces between the oil-clay feet and the clay build-up have been filled all the way around the feet.
I place some spares for pouring holes at the heels of the oil-clay feet so there will be a way to pour carving wax into the molds. I will add the other half of the spares when I do the second half of the mold.
I clamp the same plywood coddles that I used with the arm molds around the clay build-up. Once the first half of the mold has been made, I will use the custom coddles to hold the first half of the mold while I pour the second half of the mold. It is easier to do it than to explain it.
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