Castor oil is an excellent release agent for natural latex molds that are made for pouring cement. Castor Oil also has a rejuvenating effect upon natural latex and will usually bring it back to its natural consistency after it has been repeatedly used.
Castor Oil is also a release agent between a natural latex mold and a plaster back-up shell.
Make a 10% solution by dissolving one pound of castor oil in nine pounds (approximatly one gallon) of alcohol. Brush or spray into mold. For a release between the rubber mold and plaster back-up shell, simply wipe it on the back of the rubber mold while on the model. After the rubber is vulcanized, let the alcohol evaporate and then construct your plaster back-up shell.
Theres not a lot of info out there on making latex molds, much, you learn the old fashioned way.
Until I sat and read your site, I had no idea you carried castor oil, much less how much it could be used for. it's been a blessing times 10 just this week making plaster mother molds.
Have been buying it in the grocery store for years in 2 and 4 oz bottles, the Gallon is awesome, and considerably less pricey.
Thanks for your super service, and the info i find on your site.
I couldn't live without the Castor Oil when removing concrete castings from the prevulcanized latex rubber, as castings remove easily + lets me stretch the latex rubber further when pulling the rubber molds off pieces without any seams.