Hi everyone! I am new to this forum and am glad to find a place where we can discuss technical things about casting with resin and mold-making in general. I see that the majority of the casting being done here is relatively small scale parts, and so perhaps my question may difficult to answer...but I'll ask anyways in hopes of somebody being able to help me.
And I will post a photo down below.
I am in the process of making castings of a life size femal torso, originally taken from a living model. I have made the original plaster copy, on which I used brush-on 40 urethane rubber to create the mold. Over the rubber I applied polyester resin and fiberglass to make the supporting shell. The shell comes apart into two haves (the front of the body and the back of the body with the parting line down the sides), and then the rubber mold has a seam running up one side of the body, just enough to be able to pull the rest of the rubber off the model like a glove.
My question is about the registration keys and how they link to the fiberglass support shell. It seems as though the registration keys that I made with the urethane rubber are not adequate enough to keep the rubber in place on the fiberglass support shell. Essentially what is happening is that rubber and resin shell come together nicely, but the weight of the rubber pulls itself out of the registration keys which are supposed to hold it in place. What can I do to keep the rubber in place within the support shell? I am thinking that perhaps spraying an adhesive between the shell and the rubber might hold it in place long enough for the rotational casting which I plan to do. Do you think a spray adhesive will work? I'd like to know before I ruin the rubber with a sticky adhesive that doesn't work. And advice appreciated. I hope my explanation is clear, but if it is not then please say so.
Thanks!