Magic Sculpt Clay meets Mad Scientist

I'm working on a family portrait sculpture tree house for a client. It has structure built with many materials including wire cardboard and fiberglass, and a covering/ detail layer of Magic Sculpt epoxy clay.  The blue foam structures are going to be covered with MS clay leaves, but first I need to cover them with a more supportive shell. I thought about dipping them in plaster, but it tends to powder up on the surface and makes it hard to adhere the MS to. I mixed up a batch of MS and smeared it on, but that is a workout, as this clay tends to be pretty firm. I have played with various mixtures of MS clay, and Magic Smooth (the slick slimy sticky cousin) before. I even did test samples of what mixes with what, and as long as you get hardener with resin, they are compatible. I also have found that if I want to have the clay stick to the surface, of say, anything without having to manually force it into every nook and cranny, If i add a bit (about 1/8th volume) of either hardener or resin from magic smooth to the thoroughly mixed clay, and mix it in well, it has a very sticky/ tacky consistency for the first ten to fifteen minutes and then works like normal MS clay.
 
For this application though, I found that if I warm up the MS clay in the microwave for 10-20 seconds for 2 golf ball sized blobs. It mixes much more easily, and if I wet it out while mixing (dip in water or hold under running water) while I mix it; it tends to thin out slightly which allows me to smear it on the foam surfaces better. Then wet the surface again for final smoothing and sit to dry/ cure. In this way you can create a quite thin hard shell on the foam that will be a great surface for attaching your surface texture to.