DaMounty Posted September 16, 2015 Posted September 16, 2015 I trust that I am not the only person who has used a hot water tanks magnesium anode to make magnalium. Question I have is I have been weighing the anode pieces with the iron core wire. Wondering if others do that or remove it? If removing it would you have any tips tricks? I have been cutting mine into about 3" cunks and have tried hitting it out with a hammer and nail but have had no success. Trying to up the quality of my MgAl. DaM 1
schroedinger Posted September 16, 2015 Posted September 16, 2015 Just melt the mg and take a long hook and fish out the iron wire should do the trick.
MadMat Posted September 21, 2015 Posted September 21, 2015 You probably know this already, but in case you don't. There are both aluminum and magnesium anodes for water heaters. Generally, the mag anodes have a "bubble" on the top of the steel fitting that threads into the water heater. The top of the fitting on aluminum anodes are flat. Maybe simply heating the anode would release the iron core as magnesium's expansion due to heat is much greater than that of iron. Schroedinger, melting magnesium is NOT a good idea. It would have to be done in an inert atmosphere. Not to mention molten mag will react with a lot of common inert gasses, nitrogen to mention one of them.
DaMounty Posted September 21, 2015 Author Posted September 21, 2015 I've tried heating the smaller cut pieces of the mag anode, and attempted to hammer out the core - no luck.
Arthur Posted September 21, 2015 Posted September 21, 2015 (edited) Magnalium is made by melting the aluminium then dissolving the magnesium in the melt. I suspect that argon would be a cover gas that would reduce oxidation, but nothing is going to put out a flame as hot as that if the melt ever ignites. PPE and rapid egress seem good ideas. AddedSome metal boats use magnesium anodes for corrosion prevention, these may be bigger, they may be an alternate source of supply. Edited September 21, 2015 by Arthur
Mumbles Posted September 21, 2015 Posted September 21, 2015 What do you plan to use the Mg for? If you're just making MgAl, I think your best bet would be to melt a small chunk and fish out the iron core. From there you can weigh it and figure out how much iron there is in the anode. Since you need to melt it anyway for the MgAl, you could just add extra to account for the mass that's lost to the iron. If that's not an option, what about slicing off pieces of the Mg away from the core? It'd be sort of like skinning a metallic pineapple.
DaMounty Posted September 21, 2015 Author Posted September 21, 2015 I've been using it to make MgAl. Trying to get as close to a 50/50 mix as possible. My OCD kicking in. So far I have just melted both metals together and removed the core as I broke up the ingot. Thanks allDaM
MadMat Posted September 22, 2015 Posted September 22, 2015 (edited) At foundries that melted magnesium, there were two ways of doing it safely. The old way was to cover the melt with molten chloride salts to act as a sort of flux. It's not the greatest and there is the potential for accidents. Now days they use a gas shield containing sulfur hexaflouride and carbon dioxide. I did a little research on shield gases for magnesium and under the right conditions mag will react with just about every common "inert" gas with the exceptions of helium or argon. Helium has become not such a common gas anymore. I'm not sure what is behind it, but helium has become rather short in supply as of late and is getting dam expensive. Edited September 22, 2015 by MadMat
schroedinger Posted September 22, 2015 Posted September 22, 2015 (edited) Mat melting pure mg is no problem, just do it outside, away from everything that can burn (a sandbox would make a perfect place).And you can skip the inert gasses or flux salts. Just use a crucible with a really tight fitting lid e.g. a bar mixer. If you open it, and it ignites, just do what you want (fish out the wire, stir or add more mg) and close the lid. The fire will extingtush within seconds. Also it is no problem to first melt the mg and the al after that. But you have to be sure that you have enough repect for what you are handling and wear ppe and think about the next step before perfoming it. Then the risk isn't higher as if you are making it the other way around. But once you mix both the reaction turns from a smooth burning to a quite firce mix, which likes to cracle and throw sparks. @mounty you say you have always just took the wire out of the mgal ingot, then you got all you need. Just weight the wire once and account in for this next time you make mgal. If you water quench your mgal you can just take it out, since the mgal will seperate from the rod, due to the differences in shrinking. Edited September 22, 2015 by schroedinger
MadMat Posted September 22, 2015 Posted September 22, 2015 Did you mean to say melt the aluminum first then add the magnesium?? Just asking cause that sounds like the safer option
Mumbles Posted September 22, 2015 Posted September 22, 2015 It is 100% is safer to melt the aluminum first. I can only assume that by saying otherwise Schroedinger has never actually done what he described. It's asking for trouble, and adding substantial additional risk to do it Mg first, then Al. They melt as close to the same temperature, so that's not an issue. Aluminum can be pretty easily melted on it's own, but once you add the Mg it turns into an entirely different animal. Off topic, but a common tactic amongst home practitioners who make their own MgAl is to cover the surface with airfloat charcoal. It pretty effectively blocks the surface from oxidation, is more or less inert, and can be cleaned off pretty easily. Even more off topic. Helium is so expensive because the supply, or at least stockpile, is dwindling. It is in fact a finite resource, and will evaporate into space once released. Much of it was held by governments, and is most often obtained from natural gas deposits. In the 1960's the US government started stockpiling helium, since it was important for the space race. This lead to really low prices up until about 10 years ago. At least in the US, Congress decided to sell off their stockpile by 2015. This has resulted in the price of helium going up by about a factor of 5 in the last 10 years. The increasing popularity of fracking to harvest natural gas, which does not trap the helium, verses other techniques has continued to lessen the potential production. 1
schroedinger Posted September 22, 2015 Posted September 22, 2015 Mumbles i've done it both ways around and this may just be my personal experience. After all my prefered way is to just add Al and Mg to the crucible, close it up, melt everything, open to stirr a couple times and then quench it.
MadMat Posted September 22, 2015 Posted September 22, 2015 (edited) Correct me if I'm wrong, but aren't "mag" wheels for cars an AL/MG alloy? They do probably contain a fair amount of silicon though, as this is a common impurity in lower grades of cast aluminum/magnesium. I don't know what the percentages would be either. If it is a workable alloy, damaged wheels can be commonly found in auto scrapyards Edited September 22, 2015 by MadMat
DaMounty Posted September 22, 2015 Author Posted September 22, 2015 Yes I melt the aluminum first then add the Mg with the iron core. Mix them both together and cool the MgAl ingot with iron cores, then when breaking up the MgAl ingot I remove the iron core.
OldMarine Posted October 7, 2015 Posted October 7, 2015 I trust that I am not the only person who has used a hot water tanks magnesium anode to make magnalium. Question I have is I have been weighing the anode pieces with the iron core wire. Wondering if others do that or remove it? If removing it would you have any tips tricks? I have been cutting mine into about 3" cunks and have tried hitting it out with a hammer and nail but have had no success. Trying to up the quality of my MgAl. DaMI've had good results crushing the anode on my anvil with a heavy drilling hammer. Magnesium is fairly brittle. Splits away from the steel rod.
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