Metal casting experimentation

[joesregalproject]

I did tons of aluminum foundry work in high school. In metal shop we had a fully operational aluminum foundry. We used play sand mixed with gear oil to make the molds. You need to mold a sprue and a riser into your mold, and some small steam vents (poke them with a thin wire) are helpful to let any gases escape to prevent air pockets and porosity in your casting. You should use a sifter and sift the sand that is in direct contact with your pattern so that all the details come through.

Most of the stuff we made was trinket sh*t, but the process was very cool and could easily be adapted to make emblems or whatever else. I think I threw a lot of it away but I'll check around and see if I still have anything.

 

[Drkuhar]

I did tons of aluminum foundry work in high school. In metal shop we had a fully operational aluminum foundry. We used play sand mixed with gear oil to make the molds. You need to mold a sprue and a riser into your mold, and some small steam vents (poke them with a thin wire) are helpful to let any gases escape to prevent air pockets and porosity in your casting. You should use a sifter and sift the sand that is in direct contact with your pattern so that all the details come through.

Most of the stuff we made was trinket sh*t, but the process was very cool and could easily be adapted to make emblems or whatever else. I think I threw a lot of it away but I'll check around and see if I still have anything.

I just poured it in. With no top on it.So if i do like your talking about is where it is enclosed and you pour in a hole in the sand would that give a better final product.

 

[81cutlass]

Looks good! Buddy of mine did something similar with an electric kiln.

If you decide to build anything functional make sure to use cast aluminum scrap. Cast aluminum has higher silicon content which helps solidification from liquid state. Pop cans don't have that silicon and they don't cure correctly.

 

[joesregalproject]

I just poured it in. With no top on it.So if i do like your talking about is where it is enclosed and you pour in a hole in the sand would that give a better final product.

I'm not an expert, but i believe you would probably get a better final product as the casting is allowed to cool slowly and evenly and you would get less porosity as the aluminum can't escape once in enters the mold. You can probably buy or make a foundry flask pretty inexpensively. I dug through some boxes in the attic and found a few of the things I made.

Some Indian head paper weights, our school was mascot was the Indians-


These cannons, I made a bunch of these. The bases were cast, the barrels were machined on an a lathe. One barrel is steel and one is aluminum. I made a several brass ones too, no idea where they went.


This square, it was cast and machined on an overhead mill.


And by far the most intricate thing I made in metalshop, this grinder. Every aluminum piece was sand cast. The steel shaft was cut from a 1" piece of bar stock on a lathe and if you look closely, those threads on the one end are left hand. The threads were cut on a lathe, not with a die. Every surface on the flanges and the pulley was machined on a lathe.




I made a lot of other stuff too, I made a some anvil paper weights, emblems, a Hurst shift handle, keychains, some other junk. I traded a lot of stuff in exchange for English homework and I threw a lot of stuff away too.

 

[Kelvin's80442]

You should start filling the exhaust crossovers in iron, Olds heads with melted cast pistons.... 🤔

Just like that!!

 

[Drkuhar]

I finally got to try again and had a better result this time. Used sifted sand mixed with oil this time to make my mold. I did smooth up the center recesses with hot glue and painted it with some leftover blue base and then poured about 1/8" of clear in to top it off. Dont really have a use just made it to put on my speakerbox in trunk for decoration.