![]() Instead, we make a secondary channel after the core called a riser. It’s… not great and it’ll cause problems with the final cast. Metal will heat the air, causing it to rise and the metal at the funnel to gurgle. Now, there’s going to be air in the mold when you’re pouring. ![]() This is called a gate and usually runs at a 90° angle to the sprue. Often you may need to make a secondary channel to run to the core. ![]() A depth of one inch and a width of 1” to 1 ½” at the top is sufficient for most purposes. You should also widen a funnel out at the top of the sprue to make pouring the metal in easier. The sprue needs to connect with the core of the piece. I usually use a ¼” dowel for pressing space for the sprue and riser. The core isn’t your entire mold, it’s just the beginning. Respectively, the top and bottom of your molds are referred to as the cope and drag. You’ll then repeat this process for the bottom half. Prep the sand and flask as the instructions ask, then press the mold over the top half of the model. The core is the spot where your model has left empty space in the sand.Ĭonstructing the core is easiest with a two-piece model. The essential bits are the sprue, runner, and core. Instead, you have to approach the mold as a puzzle. The reality is that if you try that you’ll end up with a mess of metal that bears little to no resemblance to what you’re going for. Models are often made in two parts to make things easier when setting up the mold.įor those who’ve never cast, it would seem simple enough to just press in the parts and make a sprue leading down to it from the mouth of the flask. After that, simply pour molten metal into the depression, and you’ll be left with a single-sided piece of metal in the shape of your mold. Open face casting is very simple: press the model into one-half of the prepared mold. ![]() Wood just happens to be the easiest, quickest thing to shape in most cases. Wood is the best way to go, in my opinion, but you can also use a 3D printer to print a model in hard plastic. In the beginning, it’s best to just cast without undercuts, if you seriously need them on the piece you can cut them out with a flex shaft after the initial cast. You can cast undercut parts in sand, but it’s a serious chore and requires a lot of fine-tuning. Undercutting, when talking about molds, is just any piece that will prevent clean removal from the mold, the design should slope outwards from the center. The biggest limitation with sand casting is that you won’t be able to cast objects with undercuts. The process is simple, but the also has limitations. My first ever sand casting was a brass ornament in a frame made from scrap wood. You can also purchase casting sand or clay and then make a mold. There are kits available that will give you everything you need to pull it off. You’ll need some kind of mold and clay or sand setup to begin. Sand casting is very basic, but it allows you to quickly make complex objects in solid silver. It’s not a bad idea, lost wax casting is a serious investment. They’re a bit beyond the scope of this article, and outside of the scope of many workshops.Īll hope isn’t lost on that end, many silversmiths send out their wax carvings to be cast in someone else’s shop. Lost wax casting usually requires a kiln at the very least, and to get a really good pour you’ll need a vacuum chamber as well. Those should help you get in the right area. Pour the metal as quickly as you can while maintaining control of the torch and crucible. A slow, measured pour is often what newbies try to use… and it’ll cause problems.
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