plaster based investment mold

Casting |
plaster based investment mold

This is a plaster based investment pour cast over the wax pieces inside. I makes for an obvious set of layers to show how much is poured with each mixed batch. One of the reasons for this is to allow each batch layer to start to set and then set up in succession so the wax models will not have a tendency to float or distort in the investing process. One of the batch layers had a small amount or old red latex paint mixed in just to better expose how much was in each batch. It does not affect the mix.
What you do not see is that there is also a turn layer of 1 inch mesh chicken wire (poultry netting) also being cast around the outer edge of the mold and inside the plastic sheet tube being used for the flask. That sheet is used hundreds of times and will conform to any diameter needed as well as be adaptable for any height. It is around the chicken wire layer and circles about 2 or more times and then simply tied with a rope around it so it can not expand when pouring the investment. The very first layer in the bottom is allowed to fully set up before the rest continue and that first layer acts as the bottom plug for the whole unit. I will post several others here if this photo transfer works. bpfink