Casting pressure for clear PR?

[alankulwicki7]

Hey all,

I'm fairly new to casting and a pressure setup is on the way so I'm just wondering what pressure you typically use for casting clear PR.

FYI I'm going to be making some blanks with a swatch of fabric and want to make sure there aren't any bubbles.

Thanks!

 

[Kenny Durrant]

I've read anywhere between 30-70lbs. If I'm casting paper or pictures I always used 50lbs but I've had trouble with snakeskins so if it is something that might hold more air I bumped it up to 65lbs. I know that sounds broad but maybe it will help narrow it down. Good luck and have fun.

 

[PenMan1]

Hi Doug:
When I use pressure to cast PR, the amount of pressure I use depends on several things.

My first consideration is the type of mold used. I've noticed that my blue "tube in" type molds do MUCH BETTER in terms of lasting if I use 25 PSI or less. I have found this pressure to be satisfactory in almost every type casting I do.

Second, if I'm using PVC pipe, I can use 4O PSi without issues. I have not found a reason to exceed 40 psi for casting anything, so I never exceed that number with PR.

Third, if I am casting simple colored resins, in simple horizontal molds, I use a heated ultra sonic bath to thin the resins and use no pressure, at all. I have found in this simple setup eliminates bubbles as well as using pressure for these type blanks.

I hope this helps.

 

[alankulwicki7]

Thanks for the great info. Sounds like I might need to experiment just a little depending on the material but you guys gave me a good place to start....