Re-use of PVC

[ofd8001]

How many times could one expect to re-use 3/4" PVC vertical molds?

On the third "time around" I seem to be having difficulty de-molding several of the 12 blanks I cast. Despite more than gentle taps on a wood dowel, they are resisting my best efforts.

Thanks!

 

[Pjohnson]

I have been using the same pvc tubes for about 3 years - dozens of casts in each. They may need to set a bit longer.

 

[steve worcester]

do you use a mold release with it? Just curious as I haven't used them before.

 

[79spitfire]

I don't the PR shrinks as it sets, releasing it from the mold.