onondaga
posted this
24 December 2012
Products with any petroleum or petroleum distillates give casters that don't follow instructions the most grief. Heated petroleum spreads and gasses out. If used very sparingly, you'll likely have no problem. If petroleum flows and gasses into your mold cavities, this raises your chances of casting flaws looking like rounded wavy wrinkling or smooth rounded craters.
I have my favorite products. Some inexpensive easily available products work well too. Recently, I have tried all synthetic 2 stroke motor oil. It has no petroleum and can be applied sparingly and rubbed to a shine with a Q-tip.
The most stubborn mold I have is a Lee 12 Ga slug mold with a self centering base pin assembly. That is a lot of surfaces to keep clean and operating smoothly and mine is particularly old and worn from use. I use clear automotive dielectric silicone grease on this mold with the same sparse application method I use with the synthetic 2 stroke motor oil. The silicone has no petroleum in it either.
Many casters just swear by Kroil for lubricating mold alignment pins. Some curse the stuff for that job. It really is a matter of application. Kroil has petroleum distillates that will spread with heat and gas out, but careful minimal application will make it work fine.
I also have some medical grade pure silicone fluid, that has no petroleum or fillers. This is the old stuff that was used to fill breast implants before modern saline fluid became popular. The low viscosity of my particular silicone fluid makes it easy to apply sparingly and buff out to a shine with a Q-tip. So, sometimes I use that...I have a couple gallons of it and it even works fine for waterless/soap-less facial shaving when camping out. Gillette uses this in their Military combat shaving kit. I also use it as a fly line cleaner/conditioner and dry fly floatant...it's super for that.
Gary