old hard drives + fire + styrofoam + sand = fun.. oh yes.

TechNinja's picture

As we all know, old hard drives (and to a lesser extent, aluminum cans) are chock full of nearly pure aluminum. Also, as we all know, I don't have much money for projects, but after some research into lost foam casting, I have a new hobby. Burn baby burn....

After looking around at different ways to harness metal, my good buddy (the D) and I, decided to get together as much aluminum as possible and give lost foam casting (LFC) a try.

He's an IT guy, so he collects more than a few dead hard drives, of which their main body is almost pure AL, as are the platters. (though so I've been told, there's some evil evil chems that are released when you slag the drives, so be warned!) My dad also happens to be an IT guy, so he had about 20+ hard drives with sensitive data on them that had to be destroyed properly. Well, what better way than to turn them into something else!

Below is the spotty documentation of our first attempts at casting. I was the only one taking pictures, and I had to be hands on for this one so there's quite a bit missing.

Undocumented here are the before shots of our polystyrene positives that were directly cast. Also missing is the heating and storing process: we used a smaller camp stove propane tank, emptied then decapitated, then using a "concrete dryer" attachment to a BBQ propane tank, we heat it up to glowing red hot inside of some cinder-blocks, depositing the hard drives, aluminum cans and anything else aluminum we can find. Then using some slightly finer sifted sand, we fill a standard bucket with it then bury the polystyrene part in it.

My main project for this was my daughter's name in aluminum, for her. I figured It'd be a cool gift, a good experiment for the detail that could be had from LFC, and it would last forever.

For the aluminum Sylvia, I first printed out the letters on a laser printer, cut them out, stuck them on a specific thickness of polystyrene from some piece of packaging, then proceeded to use a blade-knife and cut them all out.

Then with 100 grit sandpaper and a Dremel I rounded the edges and smoothed the rough bits, and affixed them all to a "base" piece with tiny spots of hot glue. From the two base feet, I extended another 2 inches of sprue to protrude from the surface of the sand and act as metal guides. And it worked! (I'm as amazed as you)

1 second after the molten aluminum is poured onto the styrofoam sprue protruding from the sand
One half of a soup can acts as a container for the excess molten aluminum. The white sprue can be seen just peeking out
After about 30 minutes of flamage, the melty pot and it's load of de-slagged aluminum is ready for the first pour
The D takes aim with his home-made long handled flat tongs to pick up the melty pot. You can see our ingot cupcake pan at top.
The D very, very carefully pours about 2 cups of molten metal onto the sand, sprue and catch
Best to let it burn off.. oh and don't breath the smoke.. that'll kill ya.
This was a little bit of an overpour, so after about 2 mins, we removed the can (saved tons of time trying to saw it off later)
Our second attempt of the day, that soup can didn't fare too well
The D's first sand covered monstrosity is pulled from the scalding sand! It's... a D! You can still see the spillage attached
The D is pleased! our first cast is a complete success.. next, the knife...
[Post wire brush] Mostly a failure. The metal never got to the tip of the knife, and the can bit was a real bitch to remove.
The final results. Needed lots of work with a wire brush to get it to shine, and the knife needed lots of grinding)