First photo is just the FW shoulder pad..

i had to kinda ruin this one to get a nice full circle around the fist as there were purity seals molded into it, but nothing a sharp x-acto didn't take care of...
I then mixed up my green stuff, rolled it into a ball big enough to cover the fist, then dampened the ball and pressed it slightly against a small piece of glass. This makes for a nice clean surface (getting rid of finger prints and folds) for pressing against whatever you are trying to mold. I then applied liberal amounts of saliva to the pad and carefully wrapped the whole thing in green stuff... making sure to press evenly and solidly around it...

I then let this set up for bout 1/2 hour and very very carefully pealed it away taking care not to change the curvature of the shoulder pad.. I then let this piece dry over night. The next day i added a bit more green stuff to the back to make a handle of sorts.

and let that dry again for another day. Now i was ready to give it ago with one of the older plastic shooty terminator arms.. You have to applied lots of saliva to the new mold (or other lubricants) when doing this next part as the green stuff really likes to try and stick into all those small nooks and crevices. So i ball up a small bit of green stuff and put it directly on the arm itself, then slowly (yet firmly) press the mold onto the arm, making sure to press hard enough to squeeze out the excess green stuff and on my first go i got this one!

and finally here is the painted up test arm, will definitely add some purity seals and some other bling with doing this on the rest of my old terminators..

I do recommend patience when trying to make molds with green stuff as i had many many failures when first starting out..
ps, i recently heard about this stuff and am excited to give it ago!
Cheers,
Brose