The Final Stages of a Bronze Sculpture

We're nearing the end of the bronze sculptures posts!

Removing the screws and cleaning off any of the little bubbles of bronze that may have occured during the pour is an important step as it gives the project a cleaner and more professional look. After the bronze is whole and complete and any extraneous pieces have been welded together the patina can be applied.

There were only three patinas made available in class, green, a warmer tone, and an almost black one, by far my favorite is the darkest one. To apply a patina all that is needed is to simply heat the piece and brush on the desired concentration of the patina. Heating the piece gets rid of excess moisture in the metal and allows it to be more receptive the patina.

After the patina looks good a coat of wax helps protect it, and it's ready for display!

Pouring

The pour! 

We poured aluminum and bronze several weeks ago. I've been busy with the last weeks of school so here it is! Finally. 

For the pour we placed our empty molds in a bed of sand so that there would be less chance of splitting. It was also important that before then we made sure there were no loose pieces inside the molds that would mess up the form of the figure.

We all wore plenty of protection and looked kind of like spacemen.

The metal cools and we soak it in water til it's cold enough to remove the mold.

The pieces can be dislodged by striking the end of the piece that the metal was poured into.  

Once the larger pieces of the mold have been removed the smaller pieces can be chipped off and the piece can be blasted with air to clean off any excess silica. After that the next step is to saw off the excess metal (the screw) and apply a patina or base, as the case may be. 

Anyway, it's practically summer, and it's a beaaaauuutiful day! 

Melting Waxes

Tiny post today. The end of the semester is throwing me a loop and keeping me busy. Here's the last step before actually pouring the molten metal into the molds. 

Basically in this step, using a torch, the wax is melted out of the silica casing. One of the concerns in this is very nearly the same concern when attaching screws to the piece. When the wax is melted out, it's important to start from the bottom of the piece and melt the bottom of the piece so that the wax at the top has a place to go. If the bottom of the cup doesn't clear first, then the wax above it won't have anywhere to go and will expand and possibly damage the mold. Always point the torch down, and think through exactly how the wax will melt.

 I've been thinking about posting about video production soon, but at the moment I am far to busy actually putting together my video projects. 

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! 

We've been having some interesting weather lately. It went from absolutely gorgeous weather, to fog for three days straight, and now it's a lovely but incredibly windy day. Here's some photos from the other day down in Canal Park in Duluth.

                       

Bronze Pieces Finished!

Bronze figures are officially finished now! I've coated them each with a patina, and some have several different kinds applied to different parts of them.

More wax figures! Below is the concept sketch for my next sculpture. It emerged after a several hours of contemplation on the image of the idealized and stereotypical woman and the restrictions it puts on women. The wax figure (on the left) is going to have several poles going through the body, with several more criss-crossing them locking the figure into place. It's evolved greatly since the original concept, but I like the direction it's going.