Best air dry clay to add to mego heads?

[megoman2009]

My wife just cleaned out a small room for me to use for customizing and display!!!!! I've dug out all my half finished customs and ideas. A few of them involve cutting down heads and sculpting for modification. I'm thinking oven bake is not an option because it will melt the original mego head. What does everyone use for a reliable air dry clay or other sculpting material that won't shrink or crack?

Thanks,

Brian

[thunderbolt]

http://www.amazon.com/Magic-Sculpt-L.../dp/B003ALAZS8
stuff is great to work with, and its pretty indestructible when dry.

[sprytel]

I use DAS modeling clay.

http://www.amazon.com/Prang-Air-Drying-Modeling-Pound-387600/dp/B001GAP4Y0/ref=pd_sim_op_3?ie=UTF8&refRID=1T1YTDJMKD36QEDXS9WZ

It is a bit more finicky... but I like that it is an actual air-dry process, rather than a heat or chemical reaction.

A couple of tips when sculpting to vinyl heads.
First, you probably want to pack the head with clay before you do any modifications. "Squishing" the head could destroy all your hard work.
Second, clay does not adhere well to vinyl. I sometimes wait for the clay to harden and come loose, and then Superglue the clay to the vinyl... which produces a great, tight bond.