Making a Casting

Here we are cooking up a batch of molten aluminum. You could use old soda cans, but that's an alloy of aluminum optimized for forging operations. We are better off with an alloy designed for casting. Aluminum pistons, engine blocks and crankcases come to mind as possible scrap sources, or, you can take the easy way out and buy some aluminum ingots. In this picture you see the start of a melt. The pieces of aluminum have been arrayed around the furnace top to be pre-heated.

Hot Stuff Coming Through!

This is the dangerous bit. We wouldn't want to drop 6 pounds of molten aluminum. You can see the crucible is quite hot. You need to do this operation quickly and smoothly. Plan it out in advance. Rehearse it before you do it and make sure all the tools are where you need them. Get the crucible with the lift out tongs. Skim the crucible with the skimmer. Pickup the crucible with the pouring tongs...

Pour it In

Pouring should be done in the manner of a coed at a beer chugging competition. Pour the metal straight into the center of the sprue. Pour it smoothly, pour it fast. Don't hesistate. Do it in one continuous pour.

Do you Smoke After Casting?

Petrobond does. In fact, if the metal is hot enough the smoke will become a flame. It's only a little one and you can blow it out.

When we fill a mold we typically allow the metal to pool in a puddle at the top of the sprue. If the mold is level it will form a nice little pool. If the mold is not level it will run off in some direction you probably didn't anticipate. Uncontrolled molten metal is a bad thing, so always level the mold before pouring.

Make some Metal Muffins

We don't want to be caught short with a half filled mold. That would ruin the casting. This mistake is easily avoided by melting more metal than needed. The rest can be made into little ingots for future melting. A dry muffin tin makes a good mold for this. Steal it from the kitchen.