Some sculpting discussion going on in another thread. Thought I'd post here for anyone who may be interested.
Hi Chris, with that Super Sculpey stuff you're using do you have to sculpt the master head a certain percentage bigger than you want the final heads to come out? I mean does it shrink when it's hardened or during casting?
Howdy!
No, Super Sculpey Firm doesn't have any appreciable shrink upon curing. It's pretty darn stable. You can get a shrink in reproduction, but with the rubber resin combo I use it's virtually undetectable, less than 1%.
Mostly it's when I sculpt for reproduction in vinyl I have to take shrink into consideration. Rotational vinyl, for example has a shrink of about 9%. Half comes from the wax step, the rest from the vinyl itself. This varies slightly by manufacturer due to differences in wax formulation and temperature at which the vinyl is poured, but it's usually in the 7 to 10% range. I'll describe the whole rotational vinyl process one of these days if anyone is interested. I find it interesting, but I'm strange that way!
On a side note, to all aspiring sculptors out there, I recommend the pro quality Super Sculpey Firm. Unlike it's more common translucent pink cousin, regular Super Sculpey, SS Firm has an opaque density and gray color that makes it much easier to see the surface you are working on. And, as the name implies, it has a firmer texture so it holds it's shape better before hardening in the oven. Random sculpting thought of the day.....
I'm assuming thats different from Sculpey III? I usually use the small blocks of elephant gray.
Where can one purchase this stuff Chris?
Check out well stocked art supply stores or hobby stores. Nationally, in the US, Hobby Lobby usually carries it and sometimes Michael's stores. But you'll find better prices online.
I'll buy 5 or 10 boxes at a time from
Creative Wholesale .
They have the best price I've ever found. You'll pay around $12.00 or $13.00 in most stores, but only $8.00 to $9.00 here.
The only problem with SS Firm is if it has been sitting around too long it tends to dry out a little bit and get slightly crumbly. You can recondition the clay by kneading in a TINY amount of petroleum jelly or a TINY drop of mineral oil. Be very conservative in your use of these. You can always add a little more if you need too but too much will make it too gooey. If that happens add a little more dry crumbly clay. The use of a dedicated pasta machine will make this somewhat easier! Such machines are sold in hobby stores for use with polymer clays but you may pick one up cheaper at your local Walmart or other such store. Not mandatory, but if you are going to be conditioning a lot of clay it can be useful.
Thanks so much Chris, and if I can bug you for two more little issues I get all the time.
1) How do you avoid fingerprints?
2) How do you get them so smooth? Mine always end up with little deviations in the clay that make it look like they got punched in the jaw last week and is still a little swollen.
Well, fingerprints are fine until you get to finishing. At that point mount it on a stick or rod of some sort. I usually just jam whatever spare tool I have laying around up it's neck and use that as a handle.
To get the surface smooth, as you say, there are many techniques, I'm sure. I just use a variety of tools, both wooden and metal, to work the surface into shape.
Get yourself some cheapo wooden sculpting tools and then sand them down to a variety of shapes, but all very smooth. Rub them down with some of the petroleum jelly you've bought for your SSF and wipe them off. This gives them a nice surface. Then just use them to press and scrape the clay into submission!
I also make my own steel tools. This is a somewhat advanced project however. I use Piano wire (available at good hobby stores) of different diameters which I cast a resin handle around. I then grind, heat, hammer on an anvil, to get the desired shape and thickness. The steel is then polished to a high degree on a polishing wheel until it's absolutely smooth and shiny. It's a thing of beauty!
If I'm making a blade or spatula tool then that's the final step. But if I'm making a hook tool I then bend the steel into a hook shape then add serrations by dragging the edge of the tool repeatedly across the teeth of a flat file.
This hook tool is what I often use to scrape a basic smooth surface. You can perhaps use the edge of a no. 11 exacto blade to similar effect.
When you get down to final finishing, use a series of soft water color brushes with a very small amount of lubricant or solvent ( rubbing alcohol or naptha, just a drop!) to smooth and finish the surface. Don't be afraid to cut down the brushes to get the shape and thickness you need.
Bake it up hard! But only bake it at 200 degrees F, not the 275 they recommend. Let it cool in the oven if you can be patient enough to avoid thermal shock cracks. Now you can sand and carve if need be. If you need to add more clay, use a little p jelly to help adhere the new clay to the cured clay.
Hope that helps!