Can I harden oil based clay?

[cube5]

Hi, currently I am using Roma Plasitilina clay. It's oil based, and is said to never harden.

Is there a way to harden it? Thank you.

[paleoferroequine]

Hi, currently I am using Roma Plasitilina clay. It's oil based, and is said to never harden.

Is there a way to harden it? Thank you.

Immerse it in liquid nitrogen. Leave it there. Don't touch it .
I'm sorry.   I'm no help am I?   It's late.
No, there's no way to harden it. Maybe you should try polymer clay which stays soft until you bake it in the oven. Or epoxy putty.

[ZoPteryx]

The best you can do is paint/spray on some type of varnish.  That'll keep it safe from fingerprints and smudges, but it'll still be soft at heart.

[Himmapaan]

I think you would need a dangerous quantity of varnish to try that method. And I don't know whether the materials are likely to react against one another.

I'm afraid your best route would really be to use an air-drying clay; or as Paleoferroequine suggested, a two-part, self-curing epoxy putty. If you work more slowly (as I do) and these materials may restrict your sculpting time, then a polymer clay is best. It only cures after being baked, so you can work on it as long as you wish.

[cube5]

Thank you everyone. I guess I will try polymer clay next time. Oh, wait, I don't have an oven....

[paleoferroequine]

Thank you everyone. I guess I will try polymer clay next time. Oh, wait, I don't have an oven....

Depending on the size of you project, a toaster oven will work. That's what I use. Pick one up cheap at a Goodwill or second hand shop or the classifieds in your local newspaper or your ISP probably has a for sale section on line.