Still More...

[Kingk0ng]

...newbie questions.

Hi all, I have been lurking around here for a couple of months now and I think I have read every post and every article in the library, but I still have a couple of questions that I hope aren't too stupid.

I have made a few blanks with the Castin Craft resin from Hobby Lobby, had some success getting what I had envisioned and some failures also. First question is....some of the blanks turned easily, having pretty much the same texture as commercial blanks I have bought...others when turned were seemingly extremely hard and brittle. What causes this? Did I add too much catalyst or was there some other mistake I made?

Secondly, when is a pressure pot absolutely necessary? I have been bitten by this bug of casting and really enjoy it so far. I can understand the need for pressure/vacuum for doing things like worthless wood, but is it imperative to use a pot for just a solid colored blank?


Thanks for your tolerance in advance :biggrin:

 

[Brooks803]

Castin Craft PR is brittle by nature. There are several variables that can cause them to be more brittle than normal. Too much catalyst is one, Too much heat is another, if you post cured in a toaster oven, or if it was a particulary hot where you cast. Also the type of pigment can cause brittleness. I've had some specific micas and dyes cause this. It's been a while and I don't remember what they were.

A pressure pot is really only needed if you're putting something in the resin other than a pigment. Say chili pepper flakes, etc. It's used to get rid of bubbles that can't float to the surface due to the objects holding them down, plus it helps adhere to the object better.

If you're really going to get into casting try looking into Silmar 41 for PR. It's cheaper than castin craft (unless you have a coupon) and it's WAY less brittle and more like store acrylics if not over-catalized.

 

[Kingk0ng]

Thanks thats good to hear, it has been very hot here and thinking back the softer ones may have been the ones I did late at night when it was cooler.

I have a gallon of Silmar 41 on its way that I ordered almost three weeks ago, I don't like to bash companies but after this experience I will not order from them again.