Wednesday, May 8, 2013

Wet inlay using copper and bronze

In the last post I talked about the "dry" technique of inlaying metal clay.  This post will look at the "wet" technique.

Wet inlay is achieved by adding "wet clay" to the dried backing piece.  The base piece is created using something to create a "deep design."  That could be created by rolling the clay onto a deep texture or a PPP plate of your own design.  Since the class is about learning technique, I did not try to get creative with the design and used one of Carol's new textures plates.

Copper clay shrinks less than the bronze clay when fired.  Therefore it is best to inlay the bronze into the copper so there is less chance of cracking.  (Which can be repaired but requires additional firing time.)  My bronze in copper piece needed more finishing (basically I didn't know exactly what I wanted it to be) so I brought it home to finish. 

But I did make a copper in bronze piece (since I had never done that before.)   I wanted to see what cracking might be involved with doing it that way.  Luckily, mine didn't crack.  

The middle of the flower has a slightly different look to it than the rest of the piece. (It does not show up in the photo though.)  The Baldwin's patina acted differently on it.  The only thing we could think might have caused this was some alloying going on between the copper and the bronze.  

In order for the patina to work it's best, it is important to have the surface of the two clays even and very smooth.  Using a rotary tool, we started with 220 grit emery paper and sanded (a lot.)  After that we switched to 400 grit and finally finished up with 1000 grit.  Nice and smooth.  Actually, the more you can do in the dry state the better.  It will save time afterwards and make your life easier.  

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