Miku can now ride on her toy whale.
I have cast Miku’s whale in white bronze. This alloy looks like silver and I can use this to have a silvery white bottom on the whale. The top half of the whale will be coated with a black enamel when I do the final finish for this work.
The wax model of the whale was cut in half so that it could be hollowed out for casting. Each half was cast separately. The whale in wax weighed approximately 150 grams. By the time I had hollowed out the inside I managed to get the weight down to 90 grams.
I only had a pound of new casting grain on hand and maybe three quarters of a pound of recycled white bronze available. It was barely enough to cast the whale. As it was, I had to cast one piece and then cut the button off to use this metal for the second half.
The larger piece was cast first. This showed some shrinkage flaws near the feed on the tail and on the body. This might be because I was trying to conserve metal. The second piece was much better. There was only a small shrinkage hole in the nose that showed up when I cut off the feed sprue.
Next comes the work that can sometimes be difficult. It’s called metal chasing. This means fixing the flaws by cutting filler pieces and adding metal and soldering and filing. My torches are for jewelery and all I can do is solder, and this only works if the pieces are not too large. I really push the limit with casting these figurines. With large sculptures I think the chasing process might be easier. On larger work the bronze caster can get in with a welding torch and cut and grind.
The following picture shows how I have soldered a piece of metal into one of the casting flaws to fill it. This will get ground down and then re-soldered to fill any remaining holes around the boundary.
Once the flaws are repaired, the whale needs to be soldered together. Due to the size of whale it will be difficult to get the metal hot enough for the solder to properly flow. Instead, I was able to partially melt the solder and use it as a brazing metal. I’ll find out just how strong the joint is when I polish the whale in my tumbler.
The whale is not completely finished yet. It still needs to be worked on to attach a mounting pin and to properly clean and polish the metal. But, I couldn’t resist seeing what the complete work will possibly look like. And, for what it is worth, Miku’s whale weighs 743 grams.