Mold Making Highlights
Ingots of 319 aluminum are preheated over the exhaust hole of the furnace before being added to the crucible. This dries the ingots and heats them up, making melting much quicker and safer.
This is my pouring shank ready to go. I place an ordinary fire brick on the ground to set my crucible on before the pour. Ideally, I would have a large sand bed to work in, but economics and the neighborhood covenant cops make sure than will never happen <sigh>.
Mwahahaha!!!! I love this moment. A nice full crucible of 12 pounds of beautiful molten aluminum. Skimmed, degassed and ready to make dreams a reality!
Here is our mold ready to accept it's charge of molten magic. You will see two pouring sprues in this mold. The manifold pattern we have dictates a double pouring, so I'm going to have to work quickly.
I begin by pouring half of the charge in one side......
and the other half of the charge in the other side. Since this is a lost foam pattern, the key to pouring success is pouring the mold fast and hard, keeping the mold choked with metal at all times. This keeps the head pressure of the molten aluminum up, ensuring the mold is completely full of metal.
I pour any excess aluminum into my special ingot mold. Actually, I use old cast iron baking molds for my ingots and they work great. I spray them with a bit of WD-40 and make my aluminum biscuits. Once they are cooled, they drop right out.