Acquiring Scrap Magnesium for Making Magnalium

[cmjlab]

Question for anyone.... Where is the best place to get scrap or affordable magnesium for making Magnalium?

 

I realize this is addressed in really old threads, but times have appeared to change, and NONE of the scrap yards or recycling places are willing to part with their metals (let alone magnesium), for any reasonable price (reasonable being less than the cost of Magnesium + shipping online).

 

The only reasonable place I've found is "boatzinc.com", who sells their 5 lb magnesium boat anode for $39.99. If you can find free, or really cheap scrap AL, that comes out to much less than $14.00-$18.00 / lb for finished and classified Mg/Al.

 

There was a water heater anode website that would sell scrap magnesium anode "cut offs" (odd sized anodes that didnt meet quality control, or were the too short left over from other anodes), for a really good price. But they have been sold out for quite some time now.

 

New magnesium anodes cost $39.99 as well and comes out to a little over 2 lbs after removing steel braided core. Not really feasible.

 

Any other place that anyone is willing to share? I finished my last 5 lb anode tonight and have 20 lbs of +200 mesh Mg/Al for normal stars / etc.

But I want to make another 10-15 lbs and mill it longer for speeding up various effects like colored go-gettesr / colored Hummers / colored comets.....

 

Charles

Edited October 15, 2022 by cmjlab

[Arthur]

Anyone who sells anything below the going price is going out of business!

[cmjlab]

I'm not sure that I'd agree with that.

 

I believe that a scrap yard should not expect to receive the same dollar amount (or more) for scrap, than a business who sells chemically pure / processed / and marketed products would expect. If that were the case, then when selling a "scrap" car to a junk yard, I'd expect to be paid dealership prices for my car, instead of the current dollar value of it's weight in metal (well slightly less, as they are going to make money off the actual weight in metal). Or I'd expect it's dollar weight in metal, plus the value of any useable spare parts off the car.

 

The reasons I hear when asking local junk yards are mainly associated with legal CYA and not having to worry about being blamed if you end up being someone with intentions to harm someone somehow.

 

Charles

[Powderman]

Some car wheel rims are made from magnesium alloy...

[SharkWhisperer]

and lawnmower decks...

[Arthur]

Maybe you have a local crashed car recovery service who might be more amenable to "loosing" a alloy wheel in your direction. Sometimes having the right material, in the right mesh cuts, in store is worth the cost of buying ingredients for projects.

[cmjlab]

Appreciate the suggestions. The mag wheels would be outstanding! but all the ones I've come across lately are online, and even broken / useless are way more than the cost to buy from August. I had read somewhere about lawnmower decks, from lawn boy specifically I think, but have yet to find any lawnmower decks at all. Maybe I'm not going to the right scrap yards.

 

Arthur, I have weighed the dangers + cost ($$) + availability (time spent finding metals) and you are correct, if a very precise cut / mesh of Mg/Al is called for, then it is more cost effective to buy already made Mg/Al. However, even in that case, it's cheaper to buy more vs. less due to discount and shipping, and I usually don't need a lot of Mg/Al in a precise cut - so one could argue that route is not very cost effective either.

 

In my situation, I have the space to reduce the risk to life/property, I've already made several batches so can say I have a little experience (but certainly no expert), which helps mitigate risk a bit more. I have the space to ball mill remotely, which is my key need (milled Mg/Al).... But yes have to assume SOME risk when emptying the mill jar, or letting in air periodically to prevent pyrophoricity.

 

Overall, using the equation of $39.99 / 5lb 99.8 pure magnesium + free aluminum, and store bought charcoal in a homemade foundry and disposable crucibles.... It costs me $3.99 / pound (+electricity / goodwill stainless steel crucibles every few melts) for milled mg/Al that moves like a liquid when handled (aerated) and acts like a clump of moulding sand once it has settled, and improves color / burn speed.

 

Don't forget the satisfaction of making a quality product with your own hands, much like charcoal!

 

Charles

Edited October 19, 2022 by cmjlab

[Richtee]

Some of the transmission cases on Volkswagens were Mg. Older models I think. But metals in general are now not cheap. China ensured that in a couple ways.

Edited October 20, 2022 by Richtee

[50AE]

I definitely used an WV transmission case and later an Audi one. They were old, 4 transmission bus models. They usually look dark gray. Take some vinegar with you and pour some onto a clean spot. If it reacts and bubbles, chances are it is a high percentage magnesium alloy.

You then need to cut it or hammer/break it into spall pieces. Be careful if you're going to use an angle grinder, magnesium dust is no hoke, it tends to explode and blind you. Also magnesium dust on your clothes is a serious fire hazard and safety for yourself. A single spark can make your dust covered pants flash. There's no point explaining further what might happen to you.

P.S. Other parts are thin engine top covers. For example Opel Corsa B would have such a Mg cover, I personally tested it with vinegar (where the ECOTEC label is)

Edited October 20, 2022 by 50AE

[Arthur]

Even if (when) you find magnesium you will have to make magnalium and then machine it to powder of all the right mesh cuts, some processes make fines others make lumpy swarf.. Hopefully you can make mostly the cut you want and recast the rest.

[cmjlab]

Arthur, if that was referring to me, I agree with that. I've bought four of the 5 lb magnesium weights and made Mg/Al. They sell a 10 and 20 pound boat anode, but pound v. pound, it's actually more expensive than the smaller PVC coated 5 lb anode.

 

I admittedly do not have a screen system that can sort finer than 120 mesh. However, I don't really want any of the ~200 mesh mg/al as I've found the milled for 12 hrs Mg/Al makes better / brighter colored stars that have better critical wind velocity (as I first read about on FW.com and later tried). It also makes really loud flash in small amounts for small inserts.

 

My process is to get the following cuts:

-20+60 Mesh (great for medium to long tail of sparks on stars / great in fountains)

-60+100 Mesh (great for DE / strobe comps / makes short tailed sparks)

-60+120 Mesh (strobe / DE or Crackle)

-Milled 6 Hours (looks similar to +200-325 mesh, but is guaranteed to be -120 mesh) - works great for normal/slower burn stars

12+ hr Milled - works great for colored stars, speeds up burn, used in colored gogetter / Hummer comps, flash for small inserts.

 

Charles

[50AE]

Also I suggest the water barrel casting method to process MgAl, I used for a few times and I'd say it's the fastest way to break your MgAl. The real article was available on passfire. You're basically casting your molten magnalium into a barrel full of water. There is a small steam explosion and the MgAl concoction bloats like a sponge. When it cools down within the water and hardens, it results into crumbly sponge of MgAl and voids, it is breakable using your fingers. Very quick to reduce to small particles.

[cmjlab]

One or two of the guys that wrote the original on Passfire are on FW.com too, along with the document (though the water quenching came out later).

 

I did not work up the courage to water quench the Mg/Al till the last two 10 lb batches I made. I will ONLY do it that way now! Like you say, it's a dream to break down both for the larger mesh and the milling. I've noticed once it gets to a certain fineness though, it takes just as long to mill to where I want it, as the non- water quenched.

 

I also read that August (I think) or one of the guys who wrote the document, leave it in the water for 24 hours to build up a "carbon layer" I believe they said (maybe an oxide, or maybe water reacts to for carbide or something....?). I don't do that though.

Charles

[Arthur]

Whichever plan you prefer be cautious. I have two friends who had an inadvertent magnesium fire while messing making magnalium. Little survives that fire and nothing puts the fire out.

[cmjlab]

You bring up an excellent point.

 

When melting aluminum, and especially once magnesium is added to the melt, I've learned that amongst the several safety considerations the temperature of the melt (i.e. Aluminum should not be boiling or close to it) and limiting the melt is left uncovered and exposed to oxygen will help greatly with reducing likelihood of burn through of the stainless steel crucible. Once melt through happens there are many more hazards and issues that can go wrong.

 

Batch size is an important factor, but I've also learned that the size of the magnesium pieces can also play a role. For me, it's been better to have a couple large chunks to add to the Aluminum melt one at a time vs. adding several small pieces which tend to float and have more surface area exposed to catch fire. Also, large pieces of Mg bring down the temperature when added, and help to avoid the "too hot" issue. Adding 2 large pieces also means less time with the lid off - I add one / lid on / wait a bit, open lid / stir / add last chunk of Mg / lid on, after 5/10 min remove lid, final stir, then pour into water slowly and with all safety attire (I also use a 3/4" sheetrock panel as a barrier to stand behind when pouring to slow down any possible molten metal that may come at me).

 

Pouring molten Mg/Al into the water makes processing easier, but isn't necessary, and like mentioned by 50AE - introduces more risks (fires / personal injury / etc). One could just manually break it up then mill it.

 

Lastly, when milling, I open the jar every 2 hours to allow fresh oxygen in. I turn off remotely, slowly stand upright to avoid slamming metal media around, and stand to side with face turned away (wearing PPE) to lift opposite side of lid up and let in oxygen. After few minutes, I close jar, put on mill, start remotely.

 

When I'm done the metal is like a mill jar full of water until it settles for a few hours, then acts similar to German Dark AL.

 

Charles

[cmjlab]

Update to my milled Mg/Al process.

 

Cheapest I can find magnesium is online as PVC coated boat anode ~$40.00 / 5 Lbs (makes really good mg/Al)

 

Dumping molten Mg/Al in water was definitely best method for many reasons, and surprisingly none of it floated and nothing caught on fire. (After dumping molten Mg/Al into large bucket of water with a metal pan in the bottom to prevent melting of the bucket, I just dropped the SS crucible in to extinguish any flare up from left over dross, it went right out).

 

Mg/Al can be crunched in hand and mills to an extremely fine powder in 8 hours. I do not have a way to quantify the mesh sizes as the smallestt screen I have is 100 mesh, but the powder falls right through it without issue. Also when compared to purchased -325 mesh mg)Al, my milled powder is much finer. Stars burn much much faster with it as well.

 

For Al I used an old broken 6' step ladder and simply melted at a 1:1 (Al:Mg) ratio and it resulted in a perfectly brittle metal .

 

I made 10 lbs in one night for a total cost of $40.00 (super fine milled mg/Al with some mesh cuts frome coarse to 100 mesh for different effects - after milling over next couple days).

 

**Warning - Attempt at your own risk-------- as there are many dangers when working with molten metals and finely divided milled metals**.

 

Charles

[LuisThePyro]

Anyone ever figure out how to make the 200 mesh mg/Al ? Everyone is sold out!!

[cmjlab]

I have made several batches of Mg/Al now and the cheapest I have found for the Magnesium is a 5 lb boat anode for ~$47.00, which makes 10lbs of Mg/Al at a cost of ~$4.80/lb (plus your equip, labor, and safety).

 

*Edit - added*: Uses: I have used the classified mesh cuts to make Crackle and strobe stars / rockets, as well as some slower color stars. I've used the milled Mg/Al to make colored hummer / zipper fuel, fast burning / bright stars, flash, and I'm sure other vigorously burning comps.

 

I have not classified the Mg/Al to that fine of a mesh size, mainly because I forget to order a set of screens to do it and the cost of a set of sizing screens that I'm willing to ruin with Mg/Al.

 

When I make it, I sort it typically in a few mesh sizes up to 150, then mill the rest till it compares to Dark Al appearance, color,consistency. Then I screen the ~160 mesh size bits out a last time.

 

Safety **WARNING**: Milling Mg/Al is a very good way to get severely hurt or killed, and care needs to be taken of milling Mg/Al - remote turn on/off, periodic mill jar opening to allow fresh oxygen in, safety PPE like long sleeve cotton shirt / full pants / welding gloves / face shield)/, care taken not to open mill jar towards yourself, anti-staric, and done away from people/property/animals to avoid killing anyone / anything if something does happen, static guard, and many other safety concerns).

 

BLUF: Ask questions, understand risk, mitigate as much risk as possible, accept your possible injury if you mill.

 

Warning is not to insult anyone's intelligence, just to warn you that there is a real possibility of an incident with milled Mg/Al, and to fully understand before you OR someone else who reads this decides to start milling metals.

Edited October 5, 2023 by cmjlab

[RuthlessIridium]

I get my magnesium from old VW beetle and VW T2 engine blocs and transmission cases, I can get them for less than $50 together and I get a lot of magnesium from em, cut them up and melt away.

 

I later on found someone who sells ingots for about $2.5 per Kilogram, if anyone REALLY needs mag that bad I might be able to help.

 

Currently working on an electric furnace and trying to figure out some kind of way to melt and cast magnesium without loosing half of it to oxygen, I might share some progress posts and pics.

[cmjlab]

I appreciate the potential sources, I live near a major city and the metal collectors around me tend to not want to part with their metals for some reason, and are certainly not okay with you digging through on your own. Idk - guess they are concerned about terrorists?

 

I'm good for noe, I didn't find a source for $2.50/pound, but the Mg boat anode on sale did get me down to $3 and some change if I recall, and I was able to knock out 20 lbs (5lb Mg anode per batch) of Mg/Al so I prob set for quite a while..

[Arthur]

There will be a flux for melting mag alloys, something that puts a cap on the melting metal to reduce oxidation. Fluxes are said to include Magnesium chloride charcoal and some barium salts. Barium salts are toxic by ingestion, charcoal could be available and could be good enough to reduce magnesium losses.

[RuthlessIridium]

I have somewhere an article about diffrent flux systems for magnesium, they tried about 9 mixtures of different salts, seems intresting.

I havent tried it out but Im not sure how practical it would be for me.

Im looking into building a crucible out of a CO2 fire extinguisher, it should be enclosed and constantly flushed with Argon while the magnesium is melting, an electric furnace is a must, less hot air turbulence and much better temperature control, even the crucible will serve longer.

[Arthur]

Ultimately using a vacuum induction furnace should work, but take some time money and effort. metal can with refractory bricks including a good lid. Heat by a high frequency ZVS induction heater.

The simple method is to load the crucible with metal then cover it with charcoal to form a layer that absorbs oxygen.

[Arthur]

The people who pick up crashed cars may be able to find you a mag wheel rim, the trouble will be getting rid of a damaged tyre for very little magnesium.

[RuthlessIridium]

Ultimately using a vacuum induction furnace should work, but take some time money and effort. metal can with refractory bricks including a good lid. Heat by a high frequency ZVS induction heater.

The simple method is to load the crucible with metal then cover it with charcoal to form a layer that absorbs oxygen.

It would be very expensive to build something that can maintain a vacuum at 700C, heating would be simple, but the crucible not so much. And an obvious disadvantage is that you wont be able to add chunks of magnesium when the initial load melts and liberates more space.