One piece of equipment we found to be vital in our foundry operations was the sandblaster.
After molten bronze is poured into a ceramic shell to produce a desired casting, the bronze form shrinks slightly as the metal cools, causing the ceramic shell to crack and begin to break away from the metal.
Once the bronze in its ceramic shell cools, the cracked shell is removed by hand by the use of hammer and chisel. Inevitably, some of the shell stubbornly adheres to the metal in difficult-to-reach crevasses in the casting. This shell residue is removed by blasting it with air that contains either sand or glass beads.
The sandblaster is a steel cabinet measuring about 4 by 4 feet by 6 feet tall. It has an internal space that begins about waist high and has a sealable side entry door through which the item to be blasted is placed inside onto a perforated steel plate. Sand that is used in blasting falls through the perforations into a collecting bin where it is recycled.
A pair of thick rubber gloves and forearm extensions are attached to the front of the cabinet and extend into the interior space. Just above the glove access is a glass window that provides external visibility into the cabinet.
Also inside the cabinet are an electric light, a rubber air supply hose that has the “sandblast gun” attached at one end and leads outside the cabinet to the compressed air supply line on the other end.
Externally on the cabinet are an electric blower which blows a dust-clearing stream of air into the cabinet, and a large fabric exhaust bag which collects the dust and small bits of debris for later disposal.
The operator of the sandblaster puts the casting inside and seals the door shut, turns on the light and blower, puts his hands and forearms into the rubber gloves and reaches into the cabinet and adjusts the position of the casting, aims the gun at the area to be blasted, and depresses a pedal at the foot of the cabinet. A compressed air blast of sand then begins to eat away at the ceramic, without damaging the bronze.
The sandblaster is an efficient piece of equipment for rapidly cleaning and unifying the surface of a bronze casting.
One day an employee approached me with a concern about the sandblaster. He was worried that the internal surfaces of the rubber gloves, which of course are never exposed to external light, and which are constantly exposed to perspiration from the operator’s hands, might be a fertile breeding ground for fungus. He thought that his hands might be beginning to itch from exposure.
I replied that although I had never heard of this being a problem it might potentially be one, and I suggested we could deal with it by dusting the inside of the gloves with an ant-fungal powder. That evening I stopped at a drugstore and purchased an anti-fungal foot powder, returned to the foundry, and dusted it into the gloves.
The next day, at the end of his shift, I approached the employee to ask if he felt that we had adequately resolved his problem with the sandblaster.
His disgusted response: “Aw, MAN….Now my HANDS smell just like my FEET!”
