Heating a mold before casting?

[JMC]

Hi,

I am tooling around with some castings and I remember reading that it is a good idea to preheat a mold before casting. If that is true, can I microwave it and how long should it be heated? Any help would be appreciated.

[megowgsh]

It is best to heat a mold in a Toaster Oven.

I only do this if I am casting something without the use of a pressure pot. The heat makes the bubbles rise up and out of the mold. Heat is not needed with a pressure pot which squeezes the air bubbles into a microscopic state.

[Jerry68]

It is best to heat a mold in a Toaster Oven.

I only do this if I am casting something without the use of a pressure pot. The heat makes the bubbles rise up and out of the mold. Heat is not needed with a pressure pot which squeezes the air bubbles into a microscopic state.

Austin,

Will Dragon skin work for both types of Hydroshrink? I have my stuff and am ready to try.

Thanks!

[JMC]

It is best to heat a mold in a Toaster Oven.

I only do this if I am casting something without the use of a pressure pot. The heat makes the bubbles rise up and out of the mold. Heat is not needed with a pressure pot which squeezes the air bubbles into a microscopic state.

At what temp should I heat it up adn for how long? In this case I am casting without a pressure pot.

[megowgsh]

Austin,

Will Dragon skin work for both types of Hydroshrink? I have my stuff and am ready to try.

Thanks!

I only using Dragonskin for my molds and casting both Hydrospans work perfectly with my molds.

Good Luck

[megowgsh]

At what temp should I heat it up adn for how long? In this case I am casting without a pressure pot.

Did you make your molds without a pressure pot also?

I usually just set the temp at 225 and let it go for 5-10 minutes. Heating up the mold will lead to it breaking down sooner than if you did not heat it up first.

[JMC]

Did you make your molds without a pressure pot also?

I usually just set the temp at 225 and let it go for 5-10 minutes. Heating up the mold will lead to it breaking down sooner than if you did not heat it up first.

Thanks for the tip. I actually have started to use a pressure pot but I also have some older molds.

[Jerry68]

I only using Dragonskin for my molds and casting both Hydrospans work perfectly with my molds.

Good Luck

Thanks!
Do I have to use vasaline in the mold like the website shows. Take it easy, I know your laughing .

[megowgsh]

vaseline? ***?

[ctc]

Hmmmm....

This is so strange to me. I"ve never heated a mold, or used a pressure pot. What sort of materials are you guys using?

Don C.

[Jerry68]

vaseline? ***?

So I do not have to coat any molds with a release agent?