| Well... the pieces that I wrote about in my last bog post (3/3/14) have been gated and are safely sealed away in their investment molds. Lest anyone think that this process is a "walk in the park"...think again! Each wax maquette presents its own individual set of issues when it comes to gating... thickness, projections, details, and unusual angles. All of this comes in to play when trying to determine the most efficient direction of flow for the bronze through the piece. If you are gating multiple forms with varying shapes and thicknesses, not to mention odd angled appendages, the process is obviously further complicated. This was the case for the 3 men, a cow and a door that I just completed. |  |
The trickiest sculpture to gate, because I wanted to cast it in one piece instead of doing each part separately and then attaching them later, was going to be the man on the round base with his hand on the door. I decided that the best way to get the most bronze quickly into the piece would be to bottom feed it into the base and vent it out the top of the man's head and the top of the door. I was able to use a vise to hold the main gate while I attached the base at an angle that would allow space for the door and man to be added above the sprue cup. After attaching the sprue cup to the end of the main gate, I set it up in the vise so that the surface of the base was flat. I was then able to attach the door, the man, and his case to the base, and then turn the whole thing upside down and attach the cup to the wooden baseboard. Finally I connected the piece to the baseboard by adding vents from the top of the man's head, his lower shoulder and the ends of the door and the lowest point of the round base. Next!
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The second maquette that I added was the cow. The challenges for this piece were the delicacy and thinness of some of its parts (the tail, the teats, the ears and legs) and its variety of angles. I decided to vent out through the tail and back legs and to feed the bronze in through the head, ears, and front legs. By the time I finishd gating the teats, it looked as though I had attached the udder to a milking machine. I also made a 'just in case' spare tail and attached it to the gating. The next step was to add the 2 separate seated figures to the gating system. I positioned them so that I could have the bronze enter though sprues placed on top of their heads and shoulders and flow smoothly through the bodies. I vented them out the lowest point of the feet. Additionally, I vented out of the fingers on the right arms, as well as from the chins. The final step was to add additional diagonal braces to the venting to insure that the pieces were securely supported and would not be dislodged either in the journey over potholed and frost heaved roads into Portland or when the investment was poured into the mold.
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As the first sentence of the blog indicated, the gated maquettes survived both the trip to Portland and the investing process. The actual bronze pour will take place next Saturday and the pieces will be broken out of their molds the following week. Fingers crossed ... stay tuned!
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