Man of the Future: Step 10
Hello again and thank you for joining me for this Artist’s Studio.
The “mold” - the rubber and plaster shell, has been completed now and is ready to produce wax castings. It is the equivalent of a negative in photography (remember those?), where the image of the sculpture has been captured as negative space. The next step is to pour molten wax into the mold, rotate the mold around so that the wax just coats the inside, and pour the excess back out. This is called “throwing a wax”.
The wax is poured in and out this way until a layer is built up about 3/16 of an inch thick. This creates a hollow wax casting so that the bronze will be hollow as well. Remember that each wax casting will be used to create a bronze casting. You can see the mold of the book & hand split open to retrieve the red wax casting.
You can see how the “shim” around the middle of the piece in the moldmaking installment has divided the piece into 2 pieces at the waist. These castings are cut up further into managable sizes, and pieces are also cut out of the castings leaving “windows” (the back of the head has one). The castings are touched up or “chased” at this point for air bubbles, dings, scratches and such. Each piece is then attached to wax “cups” with “sprues”- the brown branch-like connections on the head and torso pieces- we’ll come back to these in a minute.
The completed wax assemblies will later be coated with ceramic to form a second mold into which molten bronze can be poured. The “cup” and “sprues” form the pathway for the bronze to flow through after the wax is melted out of the ceramic mold or “shell”; when the wax cup is melted out of the the ceramic mold, it forms a funnel and the sprues form pipes to disperse the bronze to different parts of the piece.
Tags: Karl Jensen, Man of the Future
February 23rd, 2007 at 8:32 pm
I love the new layout…Wordpress huh? Nice choice.
Karl, again, I really appreciate the work you went to to document these casting steps. Fascinating stuff. Obviously you are very familiar with the process, did you spend any time working in a foundry?
February 24th, 2007 at 11:08 pm
Very interesting - I look forward to watching the following steps
February 25th, 2007 at 2:51 pm
Karl: As the proud owner of a 3/4 size Summer Breeze, I’m pleased to have the chance to see such a detailed account of how you produce one of your sculptures.
The process seems to allow considerable opportunity for changes in the appearance of the work to creep in through the various stages. Is this indeed a concern you must deal with, or does it just look that way to the untrained observer?
Congratulations on another wonderful piece!
February 27th, 2007 at 12:24 pm
Thank you to all who left comments.
To answer Bryan’s question; no, I haven’t actually worked in a foundry, but I have done my own molds, waxes, metal chasing, etc in the past and have spent a lot of time at the foundry as the pieces go through each stage of the process.
To Art; first I would like to thank you for giving Summer Breeze a new home. It is always nice to hear from those who make this all possible. To answer your question, yes, there are many opportunities for alterations to occur as the piece goes from original clay to finished bronze. Some change is inevitable, as the process is so destructive, but the foundry does a pretty good job of working with the artist to make the finished product as close to the original as possible.