Want to be the next Michael Angelo? Well, now you can! However, you can do your best to be like him with this "do at home" method of creating plaster molds of objects. This allows replication of an image embedded in a plaster mold, which, from there, you can create your catastrophe...I mean masterpiece! But you must be thinking to yourself, "Oh, but how do I make the mold to model with 'cause I" stop right there! I'll teach you that part. It's relatively easy to do, and relatively cheap. Though, you're still a failure, so be sure to bookmark this so you can come back and remedy your mistakes.
Things You'll Need
- Glass fiber (or something to hold the mold shape).
- Vaseline or lubricant of sort. This acts as a releasing agent.
- Your plaster.
Step one is to mix your plaster. I'm not going to go into this, because the article isn't called "How to make plaster", it's "How to make a plaster molding". Just make sure your icky plaster is all nice and moist (bow-chiki-bow-wow). Now, at this time, you should be choosing an object in which to create the mold from. You will need some form of a container to hold this object, leaving only 2-3" on each side. Ideally, something such as a Cardboard Box Mr. Richie Rich!
Fill in the container with only enough mold so that you can place half of the object into the mold. Make sure there is around an inch of clay beneath the object. Now, all that's left for this part of the half is to go through and smooth everything out. Ensure that it's nice and flat.
At this point, use a pencil or some object of the like (if you feel like being messy, your finger is an option) to place about half an inch of circular indentations on all corners of the mold. The indentations only purpose, is to allow the plaster to flow into them. This creates a raised bump on each corner of your first mold half. As a result of this, the indentations will be noticeable on the second half of your mold.
Mold a circular tube-way which allows you to pour your plaster into. It needs to be wide enough to pour into, so you don't make a mess. Keep a towel handy.
Add your Vaseline, or whichever whatever lubricant you've chosen to use. Add a fair amount on the top of the original model, and the corners as well. You will need this. This is essential for finalization of the mold, as without it, you could damage the plaster, and the object!
This is the part where we introduce the mold addition. This should only cover the half of your object, as the other one will be worked on later. Lay it about, and let it set. It needs to be around 1" above the object you're replicating. Try to destroy any air bubbles created. You don't want those, now do you? Allow it to set. Minimum time should be atleast an hour.
Once it's set, take off the clay very gentle. Inside of the plaster, you will see the half of the object you're replicating imbedded inside of it. Take out your model.
To do the second half, do the exact same thing you just did, just reverse the side of the object. Remove the mold ever so gently, as not to damage it. Should you damage it, you can use clay, or more plaster, as a filler. When you've released the object from the mold, there will be two halves. Both will have the indentations of the object you're trying to create. Almost done!
Remember all those holes I said to add? Well, here's the part where you use 'em. First, secure both sides of the mold with a proper restraint item. Angle the molds vertically, so that the hole which you will pour the plaster in is facing up. Pour the cast into the spout you created way back. It should be capable of being on both sides of the mold. Be sure to rid any air bubbles created. The last thing you want is pockets of air being visible on your masterpiece!
Allow the plaster to set completely. Fine tune it a bit if you need, but only once it's finished (carving knife, anybody?). Clean up everything also, including the mold, so that it can be reusable.