Making Magnalium.

[TYRONEEZEKIEL]

you say any formula... sure it can. it just depends on what else is in it. I know barium seems to be a very touchy chemical. In your case you need the magnesium to basically make a slowed down, chlorinated barium nitrate flash. It all depends on what else is in it. Ive done it numerous times in red and purple stars. Edited June 13, 2009 by TYRONEEZEKIEL

[TrueBluePyro]

I use Stell ball bearings in a PVC jar, seems t work well.

[swervedriver]

I remember hearing of a fellow hobbyist getting badly burned and hospitalized using a coffee grinder to comminute magnalium, the MgAl dust and grinder blades combusted in his face. Be careful.

[Mumbles]

Now, when you say "powder" do you mean the star composition powder? Don't ask me why, but formulas behave far differently when bound than when they're in a powder state. If this is the case try cutting/pumping a few from your composition, you may get different results.

 

I speak from experience when I say that MgAl can often be used in place of Mg. Not the other way around too often though. As others have said, it may not be ground fine enough. The picture makes it look quite granular.

[Arthur]

There are uses for specific mesh cuts right down to passes 250 mesh. In fact particle size is really important to all comps. Good 50/50 magnalium is so brittle the ingot may break by hand! Certainly it will smash with hammer or pliers. One of my friends pours the fused magnalium into water to quench it then puts all the nodules into the mill with steel balls. It's too easy to make the product too fine so mill in stages take out the sizes you want as they come ready in the jar.

[NightHawkInLight]

I remember hearing of a fellow hobbyist getting badly burned and hospitalized using a coffee grinder to comminute magnalium, the MgAl dust and grinder blades combusted in his face. Be careful.

Indeed, I know the guy. He was VERY badly burned, though on his arms. He was lucky to not have it go off in his face. I wouldn't trust a blender either, to fast. Mill or mortar and pestle would be my choice.

[FrankRizzo]

Wait a second here. Did he just simply mix equal parts magnesium powder and aluminum powder, then put in in the coffee grinder?

[NightHawkInLight]

Wait a second here. Did he just simply mix equal parts magnesium powder and aluminum powder, then put in in the coffee grinder?

No. True MgAl. This was almost a year ago, I forget exactly how fine he had gotten it before it ignited. Or if the lid was open, I am unsure of that also. I asked him all these things back after it happened. It could have been an electrical spark, or mechanical action to set it off, either way...Doesn't matter much. MgAl did ignite from a coffee grinder.

[FrankRizzo]

No. True MgAl. This was almost a year ago, I forget exactly how fine he had gotten it before it ignited. Or if the lid was open, I am unsure of that also. I asked him all these things back after it happened. It could have been an electrical spark, or mechanical action to set it off, either way...Doesn't matter much. MgAl did ignite from a coffee grinder.

 

 

I find that extremely unlikely. There must have been other extenuating circumstances involved.

[NightHawkInLight]

I find that extremely unlikely. There must have been other extenuating circumstances involved.

Perhaps, I wasn't there. Maybe rust, maybe some left over oxidizer, don't know.

[justanotherpyro]

When I grind my Mg/Al I pound it down to small chunks using a hammer and its not uncommon for small pieces to ignite and spark in the process. That being said I really wouldn't recommend using a coffee grinder. I use a PVC pipe and steel bearings as well to grind it down and open it up regularly to let it oxidize a bit so it doesn't become pyrophoric.

 

As far as compatibility, I have found that you can usually replace Mg with Mg/Al with some minor tweaking. Also, everyones Mg/Al will be a little different depending on the source of the Mg and Al because Mg from something like a motorcycle part will be an alloy. Al is generally easier to find higher purity though.

[FrankRizzo]

When I grind my Mg/Al I pound it down to small chunks using a hammer and its not uncommon for small pieces to ignite and spark in the process. That being said I really wouldn't recommend using a coffee grinder. I use a PVC pipe and steel bearings as well to grind it down and open it up regularly to let it oxidize a bit so it doesn't become pyrophoric.

 

As far as compatibility, I have found that you can usually replace Mg with Mg/Al with some minor tweaking. Also, everyones Mg/Al will be a little different depending on the source of the Mg and Al because Mg from something like a motorcycle part will be an alloy. Al is generally easier to find higher purity though.

 

You get sparks because of tiny bits of rust on the hammer face reacting with the magnalium at the impact point.

 

 

 

When processing magnalium, you need to be absolutely sure that your equipment is free of potential oxidizers. Magnesium *really* likes oxygen, and will happily take it from things that you might otherwise consider inert, such as rust (Fe2O3) or sand (SiO2)..

[Bananaphone69]

I just made my first batch of MgAl, and, if I may say so, it looks superb but for minor slag at the top of the ingot. should i worry about this before breaking it down? Edited July 2, 2009 by Bananaphone69

[Mumbles]

I believe most with chip/brush it off. A copper wire brush should make quick work of it. Clean MgAl is best for obvious reasons.

[Bananaphone69]

I got a soft copper wire impregnated cloth attachment for my dremel and I'm gonna just polish it up. Thanks again Mumbles.

[Bonny]

I got a soft copper wire impregnated cloth attachment for my dremel and I'm gonna just polish it up. Thanks again Mumbles.

 

 

I think a copper brush might be too soft to get the material really clean. I use a SS brush. Also, you can save the slagg as it works well in fountains for popping/crackling sparks

[TrueBluePyro]

How-To Guide for Making Mg-Al

 

http://www.pyrobin.com/files/home%20made%20magnalium.pdf

 

Not made by me. Very nice tutorial anyway. Explians things nicely with some great photos.

[Swede]

^^ That's a very nice set of pages, thanks for linking it. Good pictures.

[Ventsi]

I really, really have to make me some of this stuff. 25 bucks a pound my ass!

What would be a good amount to start with ? Im thinking a 250 gram batch would be a good way to get a feel for working with this stuff. Now I just need to get a GOOD crucible. .... And some flippin Mg, the only Mg I know of are those darn firestarters and only have 30g of metal a pop. I can't find a local scrapyard other than one for cars. I'll have a chat with my autoshop teacher and see if he knows/has something.

Edited August 31, 2009 by Ventsi

[patsroom]

We also MUST set up some sort of a group buy, and get a half ton or so of stainless mill media. Ball mill media has always been an issue in this hobby in general. There have been workarounds, but in certain cases like this one, there just is no substitute for good stainless steel. I've emailed a supplier in Asia before, but they never wrote back. Would anyone be interested in a group by of stainless media? Even in bulk, it's going to be expensive, but not 1/10th as expensive as buying stainless balls, which are usually made for ball bearings, and have tolerances that cause them to be costly. All we need are crude balls or slugs, not perfect polished spheres that are +- 0.000001" or so.

 

 

Just wanted to know if this ideal has gone any further as I feel that this would be a good thing for more than just milling media ,ie.... chemicals various pyro supplies ect....

Edited September 6, 2009 by patsroom

[TrueBluePyro]

Here is a good place to buy Mg bars if you live in the US

 

http://cgi.ebay.com/2-Magnesium-Ingots-Am5...id=p3286.c0.m14

 

Cheap as.

[patsroom]

Thank you much for the link. I will let you know what I find out about the mg search when I finish it. Thanks again. Edited September 6, 2009 by patsroom

[Yafmot]

First, beer cans are about as pure a source of Al as youre likely to find for cheap. If you're worried about oxidation, just mash 'em first, although it is wise to get a small melt going, initially. And the stainless martini mixers with lids are ideal for this. In addition to the handle on the main vessel, I would also tack on a ring or a hook or similar to the lid, just to make it a little easier to handle when things warm up.

 

As for using a cofee mill, I dont really see any harm in it, although if you want to keep from dulling the blade, you might want to consider using LN2 to chill the stuff first, embrittling it so it will mill much faster and with less wear. You also would do well to dribble alittle bit (1 or 2 ML) into the grinder before closing. Leave the cap loose for a minute, just enough for some Nitrogen gas to evolve and displace the air, & hence the O2, out of the chamber. This should preclude any chance of the stuff going off during the actual grinding operation. When finished, briefly loosen the cap just a little to allow a bit fo fresh air, but JUST a bit. This will begin passivation, but not introduce so much Oxygen that pyrophoricity becomes likely. Do this a couple more times, with 15 or 20 minutes between cycles, giving it a little shake each time for distribution. Viola! Screen & classify & you're done.

 

I know, some of you are asking "Where do I get LN2?" Fear not. Some welding supply outfits, and just about any industrial gas outlet, will sell you a quart of it if you have a stainless thermos bottle, which is basically a small dewar anyway. The stuff is shit-cheap, about 85 cents a quart. Just be damned careful with it. It'll hurt you a lot faster, and a lot worse, than dry ice.

 

In the case of a ball mill, you can install valves & fittings on the lid to let off excess pressure from the LN2 gasification, and introduce air at the proper time and rate, again to avoid any pyrophoricity problems. You'll need a regular tire valve, and an adjustable cracking pressure check valve, to protect the vessel from bursting. Put in some LN2 (if your jar will take it; PVC should work OK), and adjust the check valve so that the cracking pressure will be about 10% below what the container will handle. (you will want to do that testing before you have any product in the jar.) Once youre finished, begin introducing air, a little at a time, to passivate the powder. If you happen to have a little N2O handy, it will work much faster due to the fact that Nitrous Oxide gives up O more readily than O2. (I could easily write a lengthy tutorial on N2O, so just trust me on this one.) Just a little squirt at a time. Otherwise you've got a nasty bomb sitting there. When youre finished passivating the stuff, it should be safe to handle. Just watch out for sparks.

Edited January 10, 2010 by Yafmot

[gordohigh]

If any of you have a friend in the concrete business, tell them to save you their worn out mag hand floats. Also, if a bull float becomes warped or uneven, it is no good for concrete work anymore and will be over 10~15 lbs of magnesium. I know harbour freight sells the mag fire starters for 2.99 and shipping weight is listed at over a pound so they might weigh enough to be worth using some in a pinch.

[Miech]

Fire starters are generally made of an iron-cerium alloy, not of magnesium. Alloying it with aluminium and trying to grind it down will almost certainly result in a metal fire, because cerium is one of the metals that become pyrophoric when ground off.

 

It's the same stuff lighter flints are made of.