Ok, problem is - I’m looking to create a lot of one-off sculptures, possibly up to a metre in size, and I’d like to be able to use a self-hardening material like milliput, as the whole process of moulding and casting is really not time or cost efficient.
Clay that needs to be fired is no good as the pieces will contain armatures, also because of this I need to be careful of shrinkage.
I’ve used Milliput on a very small scale, but my normal procedure would be to create the basic shape, allow it to dry and then carve the details. But I’m finding Milliput very hard to work with on a larger scale, it doesn’t like hand-sculpting - it tends to just bulge out all over the place if you apply pressure, and pulling on any part of the material transfers across the whole piece, which is quite often pulling armatures out of place, using a tool is no good as it’s just tearing, and trying to build up layer by layer is no use as it doesn’t seem to want to bond smoothly with itself again, it crumbles off instead.
I’ve been looking at a couple of other materials, but I haven’t had any experience with them, so rather than make a very costly mistake I thought I’d see if anyone had any suggestions.
So, anyone played with Cladium? How hard does it set?
I’ve used Sculpey before, but never realised it could be set in an oven, how well would this work if it contained armatures?
Uro Hot Set? I’ve seen this in a list of modeling materials, but google doesn’t give me any more information.
KlayroK? again, not much info.
Or any other suggestions?
Make armatures and cover them with layers of chicken wire.
Cover the chicken wire with papier maché (actually just with strips of newspaper and strong walpaper glue.
Allow to dry.
Finish the job with a relatively thin layer of self-hardening clay.
Depending on how resistant to small knocks you need them to be, you could (after the ‘allow to dry’ stage) make holes in the shell and fill the largely hollow interior with expanding polyurethane foam.
Cheers Mangetout, but sadly I don’t think that would be a viable option.
It would probably be easier to just make the entire piece out of the self drying clay, but then I have no restrictions on how heavy the piece can be.
I do however need to make these pieces relatively quickly, and papier mache takes forever to dry. Plus I think the finished article would end up too fragile, I have visions of it taking a bit of a knock and the clay cracking and flaking off, and revealing papier mache underneath, and considering how much these things are being sold for, I don’t think the clients would be too impressed.
Do you know of any self-hardening clays (or any other material) that will actually set as solid as milliput? My experience with the clays is that they end up very brittle and prone to cracking or shrinkage.
I’m not familiar with milliput, but I like Apoxie Sculpt. It’s a two part epoxy, and it hardens up in about an hour. It is easily smoothed with rubbing alcohol while still workable, and I can shape it with a dremel after it’s hard. It dries really hard. I don’t do big pieces, so I don’t know if it will be suitable for you.
Very similar stuff, Milliput is a two part epoxy putty too. It’s too “saggy” to use on anything larger. I’ve seen some reports of people claiming that once you know how to use epoxy putty you can do larger scale stuff with it, but they all suggest building it up in little layers and allowing each layer to go off before doing the next, which is just going to take too long.
No problem, it was probably the “one-off” bit. Yeah, sadly these things need to last, otherwise I wouldn’t be too bothered, I’d papier mache and plaster 'em.
Bondo is one brand of a family of 2 part polyester based filler putties that are used in auto-body repair work. The putty is gray, and the hardener is dark red, you mix enough hardener to turn the putty pink, then you’ve got 5 minutes or so till it gets too stiff to work with, it sets hard within 1/2 hour, heat accelerates the reaction, so you have to work quick on hot days. The weird thing about Bondo is that when first mixed, I find it too thin to work with on vertical surfaces, the stuff is about as thin as molasses, you’ve usually got a 2-3 minute window where it’s thin enough to work with, but thick enough to stay put.
Once set, you can sand/carve as you need to, then spray a coat or 2 of laquer primer/filler over the Bondo, then sand, and the surface will be perfectly smooth and hard.
Price is usually around $5-10 US a quart, most chain auot parts stores carry it, and places like Wal-Mart, K-Mart and the like usually carry it as well
Sculpey works well over armatures, there was an article in Fine Scale Modeler in the early to mid 90’s about using Sculpey to make dinosaurs in 1/35th scale, the author used an armature of very stiff wire for the skeletal areas, then covered the armature with aluminum foil to build out the “flesh” and reduce the amount of Sculpey needed, the foil was wrapped in fine wire to hold the shape and give the Sculpey something to “bite” into.
A couple of tips:
Areas thicker than 1" (2.54cm) will probably not set all the way through when baked, so you have to build up layers.
Unbaked Scupley will soften slighty before it sets. This can be a problem if you have to lay the item down or at odd angles to get it in the oven, the best way around this is to work in sections, build up the basic shapes, bake, then add fine details, or add fine details to one part, but leave a raw area to rest one, once baked, I’ve never had Scupley soften when reheated.
IMHO, I think Scupley would probably work best for your intended use, you could make an armature out of heavy wire or even steel rods, flesh it out with cheap aluminum foil, then skin it with the Scupley, you may even be able to make the subassemblies in Scupley, then do final assembly and fill any gaps with Milliput.
Bondo and the like are weird beasts to work with, they’re great for their intended use (auto-body), but that use doesn’t translate well to the sculpting world.
Plus, I find it hard to get a consistent amount of hardener mixed in with each batch, so some areas would set faster, other areas would set slower.
Last time I used any Bondo, I was working with quantites approx. the size of 1 measuring cup or so.
I remembered a couple of more things about Sculpey:
Acrylic paints work best over Scupley, enamels have a tendency to stay sticky. I made a custom figure in Sculpey approx. 10 years ago and painted the entire thing in acrylics, but did some detail work in enamels, the enameled areas are still sticky to the touch to this day.
I forgot to mention the biggest benefit to Sculpey: since it doesn’t set untill baked, you can take all the time you need to sculpt something, and you don’t have to worry about it setting up like you do with epoxies.
No problem, it was probably the “one-off” bit. Yeah, sadly these things need to last, otherwise I wouldn’t be too bothered, I’d papier mache and plaster 'em.