Dipping Waxes Part 2

Part 2! Now the actual dipping begins. The screws have been attached and each piece has had the surface coated for protection.

The first layer of silica is applied in liquid form. The particles should be suspended so it is important to mix this well and stir it often.  It's important to dip the piece in slowly and to make sure no bubbles form on the surface of it. Any bubbles that form in the first few dips allow the molten bronze to bubble out into the space and only provide more trouble later in the work.

Depending on the size of the piece a different amount and kind of dipping is recommended. My professor suggested that I dip mine twice in the fine silica and three times in the coarse because of their small size.

Each dip needs to dry completely before the next can be applied, and the process can take several days. It is easy to tell when it's ready to be dipped again because the coating goes from a green to yellow. Below can be seen  first dip, the wax is still visible underneath the initial layer.

Below is an example of what the finished dipping should look like. The waxes are completely hidden and the forms are muffled.

Next update should have more on the process with melting out the waxes. 

Dipping Waxes part 1

The second set of waxes is finally done after many hours of work.  I've attached the waxes to a wax cup and started coating on the silica glass pieces. First I'd like to spend some time explaining the concept of sprews* and how they function. Sprews attach the wax piece that has been sculpted to a wax cup which will be the opening that the metal can be poured through.

 *It has been pointed out the me that the term is "sprew" and not "screw." Oops, my bad.

The main sprew needs to be thick depending on the size of the piece so that as the metal cools it does not block the flow. The smaller vent exists to allow the air to flow out of the highest point of the sculpture enabling the metal to push its way through the entire piece. This is especially important in larger pieces, in smaller pieces it is not as a big a concern unless there are appendages that may not fill otherwise.

Location of the sprews is very important, and as an older art student told me, "it is best to think of it as the way the metal will flow." I had quite a bit of difficulty deciding on placement of sprews on the piece above, because it is actually longer and very delicate. Finally it was suggested I cut it into separate pieces and treat them as such, and then weld the pieces together afterwards. This made the attachment of sprews much easier, because I did not have to worry about the wax bending or breaking during the coating process.

Part 2 coming up next time, with some actual dipping!