Molding mistakes

I suppose I should talk about successes and failures. Or more importantly, I should talk about my mistakes BECAUSE there haven't been any successes and...well...I should say something, right?

The truth is that when you begin to learn how to mold, even if you have a step-by-step process, and even if those directions are phenomenal, you are still going to have to give yourself about fifteen or so tries before you get anything right, and by the way, getting it "right" isn't really the end. Once you get the mold to work, you still have to find a good "release" as well as a good casting material, and you have to find a good way to get the casting material into the mold. Plaster of Paris, for instance, doesn't just naturally fill in the mold the way water would, and when you're molding things like Land Raider doors, you really have to think about what you're going to do to, first of all, fill the mold, and second, make sure the back of the casting is flat.

I have made one mold successfully of the imperial symbol produced by Forgeworld. I used a Sculpy Mold Maker thing and filled the mold with sculpy. Popped it in the oven and wallah! But the Mold Maker was only about enough for four such molds and it costs $7. That's not horrible, but keep in mind, you're kind of limited to making things out of sculpy. I want to make Ravenars and that's just not likely to happen. The mold doesn't actually have a release agent, so essentially you're peeling the casting out which can stretch it a bit if its uncooked sculpy. Moreover, the mold doesn't go in the oven with the sculpy, so there too you have a problem. It would be much better if you could bake the sculpy in the mold and then pull it from the mold all hardened, but you can't and so the delicate bits of raveners are likely not going to work in this. At least, that's my opinion on the matter.

But that's the point, because really, making molds and casting is all a game of trying it out. Don't trust me on the sculpy thing. Until someone puts the mold with the wet sculpy in it into the oven, no one will know if this thing works.

So, here are some things that I've tried that I know DON'T work. First of all, I've been making molds with plaster of paris. Bad idea all around, but it seems to me like a good place to start to figure out, conceptually, what you're doing. And believe me, you are going to need to figure that out.

The problem with plaster of paris, as I understand it, is that you can't cast very many materials in it. Really, the only conventional stuff you can cast in it are either liquid laytex (which is too rubery to be used for much) or plaster of paris, which if you work with plaster of paris for even a day will seem like a nightmare.

The reason for this is because, no matter what release agent you use (vaseline or hand soap) the original thing never seems to have enough on it and the plaster of paris ALWAYS sticks. You end up prying the damn thing loose. This probably is easier when you're casting a vase, or something like that, but a mold the size of a land raider door simply cannot afford to chip a half inch. I'm using a dental pick to get the pieces out of the plaster (which helps), but I started using an exacto blade which basically tore my mold out. Plaster is not very solid and it cracks and flakes and crumbles so easily, that anything you use to provide the trauma necessary to release your original is likely to break the mold. I have had success with this, but my success was due almost completely to my slathering the pieces in vaseline and letting the mold dry overnight with the originals still stuck in it. This process is harrowing considering the land raider door has plaster drying to its front and as you can imagine, if it doesn't release right, you will probably never get the plaster out of all the little contours. Mine worked, but I then tried the same thing on a collection of ravaner parts without much luck. Plaster seemed to come up along the spine about 1/2 a dime in length across, and about a dime in thickness. In other words, whatever I made from the mold would have a dime's thickness worth of flash. That's no good.

Still, what am I going to cast from these molds? If the plaster is flimsy at best, what chance do I have of prying a plaster press from the plaster mold. In my mind, I can picture the whole thing cracking into powder after hours and hours of labor. I hate plaster molds.

I tried another technique which was this. I put sculpy in the plaster mold and put it in my oven. I can't tell you what level of detail the sculpy picked up. From the flinty little pieces it didn't look like much, but I don't know for sure. The sculpy dried just fine in the oven inside the mold. The problem is that it didn't seem to want to come loose of the mold and nothing I tried as a release agent seemed to work. Believe me, I tried everything. I put it in for 15 minutes, I put it in for 45 minutes. I tried each of these with vaseline, I tried each of these with a wet mold. No matter what, prying the piece loose cracked it every time. I did not, however, try different kinds of sculpy, and maybe that was my problem. After all, I remember Sculpy coming out of the oven with a little give to it, and the sculpy I was using did not, but the sculpy I was using was not one of those .$99 packages, but rather the big flesh colored stuff that comes in a pack of pound for about $12. Maybe it's different quality, I don't know. I have a chaos lord with wings made of sculpy. They're thin enough to look tattered and they aren't prone to breaking, so...

Anyways, my next experiment is actually this. I've decided to do without the permanent mold. Rather than embedding half the miniature in plasticene and making a mold from the other half. I'm going to make the mold out of the plasticene. My thought is this: make the mold, pour in the plaster of paris and then peel the mold away. Will this work? Who knows. I'll tell you the results after I'm done. Wish me luck.