Wax to Metal
Our office guy who keeps our blog running was hit by a car while riding his bike and has been out for a while, but he is back now so we can update what’s happening with Mark.
As last we saw, Little Dave had just poured wax into the mold and now we have a hollow wax copy of the sculpture. Dave then goes over the wax with small tools, almost like dental tools, to get rid of the seam and fill in any bubbles that may have formed from pouring the wax. He then attaches wax sprues to the piece which will act as feeders for the bronze when it gets poured. Finally, a big wax cup is added.
The wax is then taken into the slurry room. Sergio dips the whole wax into slurry, which is like a liquid ceramic that has binder solids in it. He makes sure that it is completely covered and that there are no bubbles. He lets the slurry run off then covers the whole piece with sand and sets it in front of big fans so it will dry. Sergio will dip the piece about 7 times, adding sand and letting it dry after each dip. Once the shell is thick enough, he grinds off the bottom of the cup then takes it to an autoclave, which is like a huge steam pressure cooker. The wax melts out and now we have a shell ready to have the bronze poured into it.
The shell is heated to about 1900 degrees and the bronze is melted at around 2100 degrees. Our guys have to wear special clothing because it is so HOT and we don’t want them to melt. They pour the bronze into the shell then let it cool. Once it has cooled, the shell is broken off and you have this section of bronze. Each piece will have to go through the same process. So, once we have all the pieces of Mark and the bench poured up in metal, we will take pictures of our metal guy welding it together.
Tell us what you think about the process and if this makes any sense!
