Casting aluminum ladles - GIF

[Frank S]

In melting any aluminum if you had a way to slowly stir the liquid near the bottom and inject pure Argon not only will this help to reduce the oxides but will cause the hydrogen molecules to be absorbed in the Argon bubbles and rise to the surface where it can be removed with the draff. This will aid in degassing by removing the hydrogen and other impurities, also will help to reduce porosity and shrinkage of castings.

[nova_robotics]

This will aid in degassing by removing the hydrogen and other impurities, also will help to reduce porosity and shrinkage of castings.

That's a good point. If I ever get some motivation I might try putting a hose and a quick connect on my kiln. It would be interesting to try, at least. But I also don't know what I'm doing. I've never cast metal before. Watched plenty of Youtube videos on the subject. Kinda like reading a book on how to swim.

[Frank S]

That's a good point. If I ever get some motivation I might try putting a hose and a quick connect on my kiln. It would be interesting to try, at least. But I also don't know what I'm doing. I've never cast metal before. Watched plenty of Youtube videos on the subject. Kinda like reading a book on how to swim.

Here is the rub. the Argon needs to bubble up from the bottom of the crucible or cauldron at a slow pace. One thing you can do is to use a tube made from just about any metal which will not sluff off anything at the melting temperatures of Aluminum. If you have a way to slowly stir the molten aluminum so much the better as the bubbles from the argon will be distributed more evenly and will absorb more of the hydrogen molecules as they rise to the surface.
So there is your challenge stir the pot inject Argon and not bubble molten metal all over the place. If you have a cauldron capable of say a 40 lb melt a rotating stir tube with vanes on the bottom with a high temp rotary swivel at the top to blow the argon through you should be golden The RPMs might need to be varied between 150 and 250 or so this all depends on the depth and the amount of metal being melted. The Argon flow and the amount of time required to achieve bets results Just think of it as stirring very hot paint you can dip out the amount of metal for your pour with ladles or if a crucible use tongs to lift it out and pour.
The biggest factor here is I can't stress this enough since for most things I don't wear much of it that is PPE and be safe never put your face or any other part of your body directly over the molten metal use every safety precaution you know and even those you don't know. Also water is explosive in any molten metal