In the world of lost wax casting a wax pattern is created and then fused to a wax runner system along with multiples of other patterns or perhaps the same pattern. Once the “tree” of wax patterns is created, the tree is coated with a fine material to reproduce fine details in the pattern and is then “stuccoed” with a coarse, ceramic material. It is this application of the coarse ceramic material process with which my most recent customer needed help. It was not so much the application of the ceramic material to the wax pattern but the refilling of the rainfall sander which is the tool that actually applies the ceramic to the patterns. Below is a photo of a rainfall sander for your reference.
As you can see a fine, water fall-like flow of sand dropping down from above provides the means for the “stuccoing” process.
The problem is that the hoppers for these machines can be in excess of 7 feet above the floor and require replenishing. The idea is to put just the right amount of material into the hopper without over-filling which has been a problem in the past with the customer dumping by hand over-head.
The solution the customer was looking for was the 1-1/2” Heavy Duty Line Vac to be used in a moveable cart-based hopper filling tool with a gallows-type over arm which can be placed above the hopper of each machine to provide the metered filling.
The reasons for picking the Heavy Duty version of the EXAIR Line Vac was for its robust resistance to abrasion from high speed materials moving through the throat area. Heavy Duty Line Vac is made of a high grade, tool steel with a proprietary surface treatment to harden the material even further to make the unit highly resistant to abrasion. The Heavy Duty Line Vac has been used with such materials as silica sand, ground glass and ground garnet for hopper replenishment in abrasive blasting applications, so it could handle the stucco material quite nicely. The higher conveying capacity of the Heavy Duty Line Vac also made quick work of the material being conveyed to make for unobtrusive service.
Neal Raker, EXAIR