Pour aluminum

You can also cast aluminum yourself since it has a relatively low melting point. Nevertheless, the casting of aluminum is associated with some effort and not entirely harmless. Below we have summarized for you what to consider when casting aluminum.

The melting point of aluminum

Aluminum is a light metal which has a relatively low melting point. Depending on the aluminum alloy present, the melting point is between 580 and 680 degrees Celsius. However, casting aluminum is by no means as easy as pouring tin. For laymen, it can even be extremely dangerous if you want to cast aluminum yourself.

Pouring aluminum yourself is dangerous

This can lead to violent blistering when you pour the molten aluminum into a mold. Hydrogen dissolves in the aluminum melt. This release of hydrogen is reduced, the more the aluminum solidifies. Therefore, this causes blistering under the solidifying aluminum.

Preferably no plaster molds

On plaster molds (which should actually be burned before use) it can even happen that all or part of the molten aluminum will literally explode and the height will be thrown. Therefore, when casting aluminum, really none of the important points should be neglected. This also includes not overheating the aluminum.

Molds for casting aluminum

In a private environment, you have different approaches. This applies primarily to the form used:

  • burnt plaster
  • molding sand
  • Mold material

Metal molds and molding material

Metal molds are extremely expensive to produce and therefore rather not typical for private or small use. When using molding material, the mold to be cast is first made of wax and then dipped in the mold material.

This must now harden, then this process is repeated again and again until the material has the required strength. Later, the wax body is then heated and melted out. More common is the use of molding sand, which works in the fundamentals similar.

molding sand

Again, positive forms are needed here in order to be able to make a negative mold with it later. However, when using molding sand, the positive bodies should be made of plastic. Here are moldings that were previously printed with a 3D printer made of plastic.

Ventilation and pouring channels

The pouring and venting channels (opposite and once highest and once the lowest point of the mold) are often made of polystyrene (colloquially polystyrene). Then these forms come completely into the molding sand.

Burn out plastic positive mold

Now, the plastic must be burned out of the resulting negative mold. For this purpose, a propane burner is suitable. After you have burned out the plastics, it is up to the heating of the aluminum. Here, too, offers a kiln, which is powered by gas (with charcoal it can take a long time).

Melt and pour aluminum

Once the aluminum has completely melted, it is quickly and generously poured into the mold. It should exit through the vent channel again. Now let the aluminum part cool down. Later you can cut off the casting at the ventilation transitions. Then the aluminum has to be filed or sanded.

Tips & Tricks

The aluminum that you cast yourself will always be of inferior quality due to the bubbles that form in the aluminum. In addition, the aluminum immediately oxidizes in the air.

Video Board: Cast Aluminum Coin Dish (Direct Pour)