HAAS Chips potential solution!

Machine Shop HAAS
#21

Oh, I had one other thought to minimize dross is using the aluminum chips from the HAAS. Rig up a form from some steel pipe (say 2.5" inside diameter) and use the press to compress the chips into tube slugs. These will reduce the surface area of the material and should make good charges for melting in our crucibles… More material in a given space…

All that said, do this because you will enjoy it. The fuel cost alone will likely be more the scrap aluminum bar or other shape stock would cost from a metal supplier.

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#22

well we have that in hand too - take block scrap from the woodshop and reduce it to charcoal… scrounge pallets and cut the larger oak framing into blocks. Part of the point of this exercise would be to make something from almost nothing. :slight_smile:

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#23

Having effectively zero experience, doesn’t the oxidation happen as the chips are created, not in the smelting process? Or is the oxidation not as big a deal as I had heard?

#24

Well you don’t actually need charcoal to get hot enough to melt aluminum. You can use wood scrap and even saw dust with a small blower (think hair dryer) to produce enough heat to melt a couple of pounds of aluminum at a time with a basic furnace made with simple refractory material (even concrete)…

At that point it is just a matter of the time spent…

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#25

Aluminum creates a thin oxidation layer immediately upon contact with air. The oxidation process your talking about is a problem and why I didn’t get much success when I first tried it. The solution is to use a flux that keeps/reduces the oxidation process. This is most problematic during the initial melting process. Once you have a pool of molten metal, that helps reduce the oxidation process.

A good flux is borax (aka washing soda).

Your still going to get may 33% of your weight as slag, but that material isn’t hazadous and can be placed in the disposal stream. It is essentially a form of rock… aluminum oxide.

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#26

Something else we’re not really considering is the large amount of chips we’re talking about. This is a fully 55gal drum, which I’m about to come pick up now.

#27

I am all for switching the requirement to dispose of the chips to the users themselves. No different from any other, cleanup after yourself.

#28

I’m not completely against the idea… I already have three boxes of scrap at my house I need to address. So it’s not a big thing for me

#29

This is a good idea, I’ll discuss at the Machine Shop meetings the and we can come up with a design and make it a group project.

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#30

Ha ha… we did just get that press… lol

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#31
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#32

A post was split to a new topic: Can we melt copper scrap?

#33

Are you proposing a group build? It’s a multi-surfaced project with high voltage, high heat and the potential to “release rapidly moving shrapnel”. We should make this.

#34

Oh boy. Yeah, it sounds like total fun. :slight_smile: Lemme think about what sort of time I have to do this… :wink:

#35

Induction heating is cool, but molten Al is reactive and we’ll end up w/ a mixed bag anyway.

An eddy current seperator would seperate ferrous non-ferrous materials.

#36

We discussed using an inert Argon atmosphere. CO2 might also work, but someone with more chemistry background would have to check that one.

Remember: We do this for fun, not necessarily efficiency. :slight_smile:

#37

Pulling a vacuum also works in place of inert gas. If using induction heating this would not be a big challenge. The short time exposed to air when pouring would be minimal and oxidation limited to surface.

#38

The induction coils would have to be water cooled anyway so a vacuum would be trivial.
A 120 to ~3V transformer could be wound easily too

#39

Vacuum requires a sealed container of some sort. A nice blanket of CO2 only requires a pit to keep it in place.

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#40

Or we could use the chips in some type of pyrotechnic application, hmmm I wonder where?

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