Kinetic Sand + Stick Welder = Easiest Aluminum Casting EVER!

I've hacked the Aluminum casting process right down to nothing. No longer is metal casting the domain of big hairy dudes in sleeveless Iron Maiden Tees. This instructable will show you how to cast aluminum parts in 5 minutes with little more than a stick welder, some graphite and kid's toy Kinetic Sand.

Step 1: Kinetic Sand, Behold SCIENCE!

Kinetic sand is a weird material, it flows like a fluid, yet it is mainly sand. The unpronounceable magic ingredient is inert, in fact, it's used in fast food to minimize frothing in the deep fryer. ( ick!)

But the really great thing about it, is it doesn't melt or burn. At high temperature it vitrifies, like glass or clay.

So kinetic sand makes a great replacement for traditional metal casting green sand molds. Don't have green sand for casting molten metal? Me neither.

Step 2: Use a Graphite Crucible and Gouging Electrode

Plain old hum-drum graphite (pencil lead) is also an amazing material. It is electrically conductive, and can withstand temperatures that will melt metal. Put your scrap aluminum in the crucible (I got mine on flea bay) and use a carbon air arc gouging electrode (from welding supplier; ask nice and they may give you a few samples! Or PM me and I'll send you a couple broken in two in a letter envelope ;-).

Step 3: Fire Up Your Stick Welder and Melt the Aluminum

In the vid, I start out with 50 amps output from a DC arc welder. I set the polarity to electrode positive and strike an arc on the aluminum in the crucible. After a brief period, I decided to increase the amperage to 110. That amount of current melted the aluminum within a minute.

Then pour it into your kinetic sand mold.

Aluminum Casting: Done.

You can improve the quality by adding a little ground up chalk to the bottom of the crucible, and by skimming off the dross floating on top of the molten aluminum prior to pouring.

Be sure to check out the vid at the beginning of this instructable for much more detail. It's about 8 minutes long and well worth the price of admission!



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    15 Discussions

    Chicken Spit

    4 years ago

    Have you tried melting small amounts of other metals yet? I will try this soon with brass, pewter, lead, copper, and maybe even very small amounts of steel!

    1 reply

    Yes, bronze. I does not work when the arc is directly applied to the metal. One must use the crucible as a resistive element to heat the metal.
    Do have fun, be careful and I'd love to hear your results!


    3 years ago

    Where do you get your gouging electrodes


    4 years ago on Introduction

    I like the concept. What is the current path? How much of the kinetic sand is lost in the process?


    6 replies

    Current path: (I feel like this is a electron flow vs. conventional trap)

    Current goes through the +ve welding stinger, the copper jacket on the graphite electrode, through the graphite tip of the electrode, through the arc gap, into the aluminum, through the graphite crucible and base sheet, through the steel workbench to the -ve welding ground clamp. or exactly the opposite.

    kinetic sand: depends how messy you are. The sand gets discolored, but maintains the same properties. It is re-useable.


    No trap here! Thanks for the clarification. I didn't know if the crucible would carry the current without being damaged. Do you know if the crucible generates any heat as a result of the current flow through it(resistance) , or is all the heating the result of the arc?

    Have you tried it with A/C current?

    What weight/volume do you usually do in a pour, and how large is your largest?

    Just priced some of the Kinetic sand. Think I'll wait before I order 50kg or so for my "sand" box. :>) Any chance you can spell that unpronounceable ingredient?

    Thanks for the reply.

    1. little of both

    2. no. but it would work. you want 100s of amps

    3. not much thus far say 50-100g

    4. Polydimethyl siloxane, not available on Amazon, I checked.

    Thanks very much for the info. If I get around to trying this I write back.

    I found some pdms. Smallest I could find was 500g for $100+ (us).

    The MSDS mentions formaldehyde production at above 150deg C.

    Thanks again.

    both MSDSs that I looked at (sigma-aldrich and labsupply) don't mention anything like formaldehyde production. Can you post a link to your MSDS?


    Bottom of the 2nd page.

    I think if you're pouring outside, it would not be a significant hazard.


    4 years ago

    This is a process used quite commonly used in steel production and you have maybe unknowingly created an electric arc furnace

    1 reply

    Reply 4 years ago

    that's about the same process for melting aluminium in fact.