PR Shrinkage and bonding

[gerryr]

For those who cast PR, does it shrink a little, a lot or none at all?
Does anyone know if PR will bond to acrylic?

 

[rickbw]

The PR definitely shrinks a little. I cast in both sport drink ice cube tubes and in silicon molds. The PR molded in the silicon molds show shrinkage of up to 1/8 - 1/4 inch. It is hard to see in the ice cube tubes, but the shrinkage allows me to push out the casting.

I'm not sure of PR to acrylic, but I would assume the answer is yes.

 

[Glass Scratcher]

Originally posted by rickbw<br />The PR definitely shrinks a little. I cast in both sport drink ice cube tubes and in silicon molds. The PR molded in the silicon molds show shrinkage of up to 1/8 - 1/4 inch. It is hard to see in the ice cube tubes, but the shrinkage allows me to push out the casting.

I'm not sure of PR to acrylic, but I would assume the answer is yes.

1/8 - 1/4 of an inch?!? Is the shrinkage cumualtive or is it that much on each of the three axis of the casting?

.

 

[rickbw]

I am estimating the shrink, perhaps 1/4 inch is too much. But it appears (visually) to be length more than width. I use rectangle silicon molds from gadget (Matt).