Good source for cheap magnesium

[killforfood]

Magnalium is one of those stupidly expensive ingredients that seems to be prolific in pyro comps everywhere, especially in rubber star comps.

You can hate the Skylighter prices but you gotta love the tutorials.

http://www.skylighter.com/fireworks/how-to-make/colored-screen-sliced-rubber-stars.asp

 

Fortunately you guys have written some excellent instruction for homemade magnalium.

Home Made Magnalium PDF

 

I love do-it-yourself projects and this one looks just plain fun. I need to kick it up a notch though and found myself scrounging the isles of the local thrift stores for a suitably large stainless crucible. What I found for the grand sum of a buck 99 was a nicely tapered stainless can that could easily cook off ten pounds in one go. I also found a suitable stainless lid for 99 Lincolns. I'm thinking the furnace will need to be a steel 5 gallon bucket with a bunch of 1" holes drilled around the base like the chimney charcoal starters have. Some experimentation will be in order but I'm guessing that a full bag of briquettes will be required to cook off ten pounds of alloy.

 

I was having difficulty sourcing magnesium until I chanced on a Craigslist add for Humvee magnesium run-flats. It turns out that Humvee run-flats are 94% magnesium the balance is mostly aluminum.

An example of the element Magnesium

 

The Humvee run-flat alloy is AM60. This will be 6% aluminum and .2% Zn and or .15Mn.

http://www.journalamme.org/papers_vol31_2/31234.pdf

 

They weigh 23Lbs each and can be purchased online for $34.95ea. Or as in my case, $10 for a broken one on Craigslist.

23Lbs magnesium for $34.95

 

An even better source may be Four-Wheelers.

If you scroll down through these forum pages, you will see that the Four-Wheelers cut off most of the magnesium and just use the center hub for a bead lock. The rest I assume is DISCARDED. Ding, Ding, Ding… Source of free magnesium. It might be worthwhile to post a thread in one of these four-wheel forums that pryros have need of their scraps.

Four-Wheeler forum thread, Modfying Humvee run-flats

 

Four wheeler-Wheeler thread, Modifying Humvee run-flats.

 

Eventually I'll post the results of how I cooked a lifetime supply of magnalium in on batch or something on the futility of exstinguishing raging metal fires.

 

 

 

 

 

 

 

Edited January 27, 2011 by killforfood

[oldguy]

Mom & Pop tire & wheel shops & auto wrecking yards are a good source for scrap Mg.

 

I visited several & searched through the piles of old mag wheels looking for damage or broken ones..

 

I found a trunk full of damaged ones in a single afternoon.

 

Which they sold me for a few bucks apiece.

 

Same as you, for crucibles I scrounged a couple stainless steel containers with tight fitting lids from thrift stores for squat price. Which I modified be drilling holes in & added long steel bolts withy nuts as handles on each side. Which serve to hold the crucibles at the proper height in the pipe & made it safer to remove the hot crucible once you have a batch made.

 

I made 2 crucibles so I can replace one into the pipe for a second batch, while cooling the first. As the pipe full of briquettes burn long enough to do repeated batches, if you add a few more during the process.

 

At a scrap metal place I bought a 24 inch tall 12 inch diameter 1/4 inch thick piece of thick steel pipe, then welded on short iron angle legs, interior steel cross bars to hold in the briquettes in & used a torch to cut additional air slots on the lower end of the pipe.

 

Works like a Champ.

 

If you have never made your own Mg/Al, I suggest you start small, just for safety sake.

 

There is a little bit of a learning curve to get it right, without endangering yourself or property.

 

I did a few 500 gram batches in a charcoal starter before I went bigger.

Edited January 27, 2011 by oldguy

[killforfood]

If you have never made your own Mg/Al, I suggest you start small, just for safety sake.

 

There is a little bit of a learning curve to get it right, without endangering yourself or property.

 

I did a few 500 gram batches in a charcoal starter before I went bigger.

No worries oldguy, I also bought the beginner size to practice with.

 

 

http://img.photobucket.com/albums/v236/killforfood/Pyro/REM1Argentino1879RollingBlock.jpg

 

 

 

 

The main reason for wanting a larger crucible is that I won't burn up a dozen saw blades making itty bitty chunks small enough to fit the crucible.

The other reason is genetics.

 

 

 

 

 

[Bonny]

No worries oldguy, I also bought the beginner size to practice with.

 

 

http://img.photobucket.com/albums/v236/killforfood/Pyro/REM1Argentino1879RollingBlock.jpg

 

 

 

 

The main reason for wanting a larger crucible is that I won't burn up a dozen saw blades making itty bitty chunks small enough to fit the crucible.

The other reason is genetics.

 

 

Depending on your Mg source, you might not need a saw. All of mine (from motorcycle parts, wheels etc...) was reduced by smashing with a hammer.

If you are using solid bar stock or something, then cutting is needed - or a huge crucible.

 

 

 

[Mumbles]

The large crucible looks quite a bit like a SS garbage can I've seen at some big box stores. It might be a suitable source for those in the need. I'd be worried they'd be too thin for this, only because I'd be really worried about a 15lb MgAl spill Depending on how well they nest, using two or more, perhaps with sand in between on the bottoms could be used for peace of mind.

[killforfood]

Sorry double post

 

 

Edited January 28, 2011 by killforfood

[killforfood]

It is a bit thin at the top but gets thicker towards the bottom where it matters. I intend to set it up inside of a steel 5gal bucket with some sand in the bottom for protection. I may put this off until dryer weather though because the thought of molten metal spilling onto wet dirt scares me. Anything wet around molten metal scares me. I work with a guy that used to work in a brake drum foundry. One late night for entertainment they decided to sprits a reject drum with water and toss it into the re-melt furnace. He said it exited through the roof and they never did find it. I can't say if the story's true or not but it sounds plausible.

I guess you could say they invented a new type of steam engine.

 

We had a steam explosion at work and it blew the roof off of the whole foundry area. Apparently there are water jackets that keep the heating elements cool. That sounds oxymoronic to me but that's how they're made. One of them ruptured and sprayed water into the furnace. There was a huge concussion and metal fires everywhere; I thought an airliner had crashed into the plant. There was a forklift parked in front of the furnace when it blew. The forks were still sitting there on the floor but the forklift was blown backwards through a cinder block wall. I still can't figure how that's possible. But it's true, I saw it. By the grace of God none of the foundry guys were injured they had left minutes before to take a break. A couple miles away, my wife was at home and she said it shook the whole house.

 

Yah, I think I'll wait for drier weather.

 

Edited January 28, 2011 by killforfood

[Bonny]

It is a bit thin at the top but gets thicker towards the bottom where it matters. I intend to set it up inside of a steel 5gal bucket with some sand in the bottom for protection. I may put this off until dryer weather though because the thought of molten metal spilling onto wet dirt scares me. Anything wet around molten metal scares me. I work with a guy that used to work in a brake drum foundry. One late night for entertainment they decided to sprits a reject drum with water and toss it into the re-melt furnace. He said it exited through the roof and they never did find it. I can't say if the story's true or not but it sounds plausible.

I guess you could say they invented a new type of steam engine.

 

We had a steam explosion at work and it blew the roof off of the whole foundry area. Apparently there are water jackets that keep the heating elements cool. That sounds oxymoronic to me but that's how they're made. One of them ruptured and sprayed water into the furnace. There was a huge concussion and metal fires everywhere; I thought an airliner had crashed into the plant. There was a forklift parked in front of the furnace when it blew. The forks were still sitting there on the floor but the forklift was blown backwards through a cinder block wall. I still can't figure how that's possible. But it's true, I saw it. By the grace of God none of the foundry guys were injured they had had left minutes before to take a brake. A couple miles away, my wife was at home and she said it shook the whole house.

 

Yah, I think I'll wait for dryer weather.

 

 

Some guys pour the liquid melt directly into water when making MgAl...Dagabu for one I think. I think it makes the product even more brittle. I haven't tried it but I might this summer. I've generally made mine in a bowl, and once cool enough to solidify, immersed it into (large) a barrel of water. Lots of steam, but no worse tha hardening steel with water quenching.

[dagabu]

I did change my routine slightly and took the advice from another member. I now use a 4' section of 2x2 angle iron to pour my MgAl into a 30 gallon drum of water though I may be buying it instead from a good friend.

[killforfood]

I assume this was to move you away from possible spatters.

[Algenco]

I'll be watching for progress reports.

You'll need to watch that the Al doesn't harden in the bottom of your crucible.

After adding the Mg the temp drops and a layer of Al will harden in the bottom.

With 2.5lb batches it takes an additional 10 minutes after everything appears to be melted to get that bottom melted and mixed.

 

I would like to be able to do 5lb, don't know about 10lb+

 

I have over 70lb so far

Edited January 29, 2011 by Algenco

[killforfood]

The large crucible looks quite a bit like a SS garbage can I've seen at some big box stores. It might be a suitable source for those in the need. I'd be worried they'd be too thin for this, only because I'd be really worried about a 15lb MgAl spill Depending on how well they nest, using two or more, perhaps with sand in between on the bottoms could be used for peace of mind.

Mumbles I also saw some nice big Stainless steel champagne coolers at the thrift store that had a nice shape and heavier walls. Some of them were double walled and most had lifting handles. I should have probably bought one of them but I was being cheap.

This site shows a bunch of examples.

 

http://www.shreejiindia.com/b.html

 

Edited January 29, 2011 by killforfood

[killforfood]

I'll be watching for progress reports.

You'll need to watch that the Al doesn't harden in the bottom of your crucible.

After adding the Mg the temp drops and a layer of Al will harden in the bottom.

With 2.5lb batches it takes an additional 10 minutes after everything appears to be melted to get that bottom melted and mixed.

 

I would like to be able to do 5lb, don't know about 10lb+

 

I have over 70lb so far

Algenco,

 

This is the kind of information that I surely would have learned the hard way.

I appreciate the tip. It may require that I add the magnesium in smaller pieces and at a slower rate. The stirring stick should give me a feel for how things are doing in the bottom of the pot.

 

 

70lbs Are you serious? That would last me 10 lifetimes.

[Bonny]

I'll be watching for progress reports.

You'll need to watch that the Al doesn't harden in the bottom of your crucible.

Great advice Algenco.

I've had this happen. Huge PITA, you think you have a nice MgAl ingot/chunk, whatever...but it won't break up nicely. Then you need to start over, remelting etc.

 

 

Algenco,

 

This is the kind of information that I surely would have learned the hard way.

I appreciate the tip. It may require that I add the magnesium in smaller pieces and at a slower rate. The stirring stick should give me a feel for how things are doing in the bottom of the pot.

 

 

70lbs Are you serious? That would last me 10 lifetimes.

 

Stirring helps a lot,as Algenco said allowing the heat enough time to do its work on the Mg.

In my case (now) the melt is plenty hot (gas fuelled blacksmith forge) that I no longer need to worry about temps...but I still stir it vigorously.

Edited January 29, 2011 by Bonny

[dagabu]

I assume this was to move you away from possible spatters.

 

Exactly the reason. I was chastised for dropping it from a height so i switched it up some.

[killforfood]

I've been giving some thought as to how I will minimize oxidation and any chance of a magnesium fire. One of the things that I need to concentrate on is controlling my melting temperatures. Anything higher than what is needed to melt the magnesium just increases the chance of a fire. Since my briquette furnace will not have a temperature gage or thermostat, some other means is needed to control the temperature. I got to thinking how un-melted metal absorbs energy up until it is fully melted. This in affect is a way to control the temperature right at the melting point of the metal being added. As long as the energy is going into melting more metal; the temperature will be stable. To keep the temperature from rising unnecessarily, immediately add more metal just as soon as all of the metal in the pot has melted. When the magnesium is added it becomes much more critical to not overheat the mix. Now I know some of you are thinking, hey we just warned you that adding the magnesium too quickly can cause some of the aluminum to solidify in the bottom of the crucible. I thought about this and part of my plan is building a fire that's hot enough to keep things melted but that can also be controlled by adding metal quickly. It will be a learned balancing act.

 

The other thing I've been giving some thought to is the methods of fluxing to control oxidation and prevent magnesium fires. I've seen where you guys add the charcoal at the end of the melt and the beginning of the cooling phase, but why not add a pinch just as soon as the magnesium is beginning to melt? In fact what would it hurt to maintain a smothering layer during the entire melt?

 

Ending on a happy note, Goodwill Ind Sold me a nearly new Webber Charcoal Chimney for $4.95. It's larger and much more robust than the cheap ones at Walmart.

[dagabu]

The other thing I've been giving some thought to is the methods of fluxing to control oxidation and prevent magnesium fires. I've seen where you guys add the charcoal at the end of the melt and the beginning of the cooling phase, but why not add a pinch just as soon as the magnesium is beginning to melt? In fact what would it hurt to maintain a smothering layer during the entire melt?

 

I have used sawdust, Mica, charcoal, corn meal, whatever contains a masking gas or airtight covering so that O2 wouldn't get to the mix. I tried Argon but I didnt have a regulator to keep the flow low enough and more research could be done on this idea.

[killforfood]

Is there any downside to adding a layer of charcoal at the begginning or early in the melt?

I'm not to concerned about the aluminum but I would like to have a good layer of charcoal for when the magnesium goes in.

[dagabu]

Nope, it all floats on top and burns off leaving only slag to be skimmed off.

[killforfood]

Does your magnalium ever burst into flames while it's rolling down the channel to the water?

It seems that every thing can be controlled right up to that point and then it's totally exposed to atmosphere.

[killforfood]

One other thing, I have a big bottle of CO2 shielding gas but I read somewhere that magnesium burns so hot that the CO2 will decompose. Any comments?

[Algenco]

I suggest you do a few smaller batchs first, you could test different methods without risking setting the Earth ablaze

 

I use 2 small "Drink mixers", I can do 20lb in around 5hrs, no need to larger batchs.

Remember, alloying is only part of the process, if then has to be broken up and classified.

[Ralph]

One other thing, I have a big bottle of CO2 shielding gas but I read somewhere that magnesium burns so hot that the CO2 will decompose. Any comments?

 

yes CO₂ will act as an oxidiser for magnesium giving off carbon just as the oxide of iron (any of them) will act as an oxidiser for more reactive metals such as Aluminium or Magnesium