memo Posted July 31, 2016 Author Posted July 31, 2016 pat let me know how it works out, how about sloid scrap from your bike shop ? memo
OldMarine Posted July 31, 2016 Posted July 31, 2016 I haven't asked about larger chunks/ because the turning are copious and free. Guess it couldn't hurt to ask though!
WSM Posted August 1, 2016 Posted August 1, 2016 (edited) My bucket furnace blasts flame around the crucible so I'm concerned any lighter tubing feeding the argon would quickly oxidize and/or melt. I'll attach my regulator hose to the end of a 3' length of pipe to protect it and leave me a handle to hold the lid on while moving the crucible to pour into the bucket.It's gonna be interesting if nothing else! Well, sure; that makes sense. You may still want the cover gas flow to be down to nearly nothing though (just barely positive pressure is all you need). WSM Edited August 4, 2016 by WSM
MrB Posted August 2, 2016 Posted August 2, 2016 What if you could fill a sealed canister with barely positive pressure argon gas before putting it in the furnace? If it's not strong enough you have a pipe bomb, of course, but that could, should work, i think?B!
OldMarine Posted August 2, 2016 Posted August 2, 2016 I figure with a flat plate lid not sealed to the crucible 1/2 psi or so from a 1/4" pipe should be plenty to exclude oxygen. I can increase the pressure as needed. I was thinking at work today (don't tell my boss) and decided to sort out the finest turnings to experiment upon. They're always the hardest to keep from igniting so if they work, it all should.
WSM Posted August 2, 2016 Posted August 2, 2016 What if you could fill a sealed canister with barely positive pressure argon gas before putting it in the furnace? If it's not strong enough you have a pipe bomb, of course, but that could, should work, i think? B! I'm not thinking of adding the gas once (to a sealed container), but a slow continual feed to a covered crucible with a loose fitting lid (allowing the argon to leak out, while preventing the incursion of atmospheric gasses). I bet you knew that. WSM
WSM Posted August 2, 2016 Posted August 2, 2016 I figure with a flat plate lid not sealed to the crucible 1/2 psi or so from a 1/4" pipe should be plenty to exclude oxygen. I can increase the pressure as needed. I was thinking at work today (don't tell my boss) and decided to sort out the finest turnings to experiment upon. They're always the hardest to keep from igniting so if they work, it all should. That would work, and if the lid fits close enough, very little gas flow would be required to keep the air out. Let us know how it works out. WSM
MrB Posted August 4, 2016 Posted August 4, 2016 I'm not thinking of adding the gas once (to a sealed container), but a slow continual feed to a covered crucible with a loose fitting lid (allowing the argon to leak out, while preventing the incursion of atmospheric gasses). I figured that was the plan, i just thought of doing it differently. As long as it doesn't catch fire, it "should" only be the heat expansion causing the pressure to climb. So while the pressure most certainly would climb, it might not go crazy high. Only benefit is that it would save you some argon gas. Drawback would be a much more complicated crucible. And i think it would still be sacrificial...B!
OldMarine Posted August 4, 2016 Posted August 4, 2016 Apparently they shipped my crucible via B-52 bomber and dropped it from 35,000 feet. The manufacturer is sending another asap.
WSM Posted August 4, 2016 Posted August 4, 2016 Apparently they shipped my crucible via B-52 bomber and dropped it from 35,000 feet. The manufacturer is sending another asap. Was this crucible graphite? I imagine the rubble could be useful (but not as useful as a crucible ) for something. Maybe powder it and see if it helps cover the melt? I know powdered graphite helps in some rocket or gerbe nozzle formulations, to help prevent erosion. Hopefully the replacement comes soon. Please post photos when it comes. Thanks. WSM
WSM Posted August 4, 2016 Posted August 4, 2016 I figured that was the plan, i just thought of doing it differently. As long as it doesn't catch fire, it "should" only be the heat expansion causing the pressure to climb. So while the pressure most certainly would climb, it might not go crazy high. Only benefit is that it would save you some argon gas. Drawback would be a much more complicated crucible. And i think it would still be sacrificial...B! The only way I could see that working (with a sealed crucible, I mean), is if some sort of high temperature pressure relief valve were mounted to the crucible. I think the slow flow of argon for slight positive pressure within the crucible is a simpler solution to the problem. I was considering using a cast iron dutch oven with a lid for a crucible. I have a friend who used one (many years ago) to make magnalium successfully, but he melted the metals by placing the dutch oven in a pile of burning wooden pallets; not in a gas kiln or forge. WSM
August Posted September 8, 2016 Posted September 8, 2016 Good luck with Mg chips or ribbons. I found it not worth the effort to deal with. Personally I buy Mg by the pallet of ingot. Making the alloy is the easy part. Next you will need a set of dedicated screens and a hammer mill. Cheapest functional unit is a ninja ultimate blender, the pro and lesser versions not suitable. Probably going to have over $500 invested before you see your first bit of usable MgAl. BTW, I have 8_20, 20_30, 30_60, 60_100, and 160_230 in 5lbs bags for $50.
WSM Posted September 9, 2016 Posted September 9, 2016 Any -350 mesh? August makes a nice product. I've seen it several times at PGI and acquired some for my own use. WSM
August Posted September 9, 2016 Posted September 9, 2016 I have 325_Pan. Dagabu, I recognize the avatar. Different name next door?
dagabu Posted September 9, 2016 Posted September 9, 2016 Yupper! Same crispy-critter! I may need some, let me check inventory on Monday. I am an hour away from my build site and have the granddaughter today.
joeyz Posted September 11, 2016 Posted September 11, 2016 (edited) any 1 pound sales? i think 5 pounds may be too much for me. not sure yet. thinking what i can use it for. right now i making orange sunset stars that calls for 200 mesh magnalium. Edited September 11, 2016 by joeyz
NeighborJ Posted September 11, 2016 Posted September 11, 2016 (edited) I'd certainly be open to buy an unscreened batch so I can get a little of everything. I can screen out what I need for those rarely used larger sizes. And if I can't use some of it I can always mill it down to a usable size. Or I could split a batch with you Joey. Edited September 11, 2016 by NeighborJ
joeyz Posted September 11, 2016 Posted September 11, 2016 sounds good to me chief. sounds like hes got some great stuff according to other pros here. this is one of those cases of better to have and not need rather than to need and not have. i guess i can use this in ground strobes and fountains and other stuff.
OldMarine Posted September 11, 2016 Posted September 11, 2016 I just used August's 200 mesh in a batch of crackle and it's almost timed too well. Three or four in a Dixie cup with dusting of BP lit with visco go off in almost perfect unison. These might not be good as standalones but they'll make some awesome crackling glitter comets!
August Posted September 12, 2016 Posted September 12, 2016 I can sell unscreened, but don't recommend it. That's the most time consuming part, and requires dedicated screens. I shake two pounds for fifteen minutes then empty, clean the screens and start over. The 8_20, and 20_30 mesh is sifted out before going in the sieve shaker. When I'm fully stocked I have ten different sizes. Want to shake out a pound of 230_325? Recommend starting with twenty pounds of unscreened, probably get ten pounds of 30_60. Individual pounds are $12/#. Currently I'm out of unscreened, but will post in agora when I start grinding again. Just read about the agora section, now I need to find it.
NeighborJ Posted September 12, 2016 Posted September 12, 2016 Yeah I thought better of it after the post. In screened is not the way to go. OM, I think my supply of mgal is getting stale or something, they only sizzle now but they give the comets a huge bushy tail. I definitely want to try this stuff in the 200 mesh, it will match particle size better.
Crazy Swede Posted September 18, 2016 Posted September 18, 2016 A long time ago I studied the performance of magnalium I made with different ratios between magnesium and aluminium. I produced the samples by mixing the correct amounts of atomised aluminium and course magnesium and pressed the dry powder mixes to pellets that were covered with a salt flux in crucibles. The crucibles were put in an oven flooded with argon gas and after melting and cooling the flux was washed away with water. Argon gas is not needed if a proper flux is used and if the magnesium is in the form of chunks or ingots. I have seen large scale production of magnalium in Italy where they put ingots of Al and Mg in steel trays and covered it all with a commercial flux powder that came in 25 kg bags. The trays then slowly went through an oven on a conveyor and after cooling the flux was brushed away and the big and brittle peace of MgAl was broken to smaller chunks before milling. I'm actually not sure if the powder used was a true flux or if it only was an inert powder mix that protected the metals from the atmospheric oxygen. If people want to experiment I would suggest oxides of aluminium, titanium and/or zirconium since they will be inert to magnesium. Some comments to the discussion so far: Only the noble gasses are truly inert to magnesium. Using nitrogen or carbon dioxide will fail and could even be dangerous! Using sulphur as a flux sounds very dangerous since it can react with both metals in a similar fashion that zinc can burn with sulphur. I also guess that it will boil or burn off before the magnalium is formed, forming extremely obnoxious fumes.
OldMarine Posted September 18, 2016 Posted September 18, 2016 I've tried a couple of times since I got my new crucible. I bled argon in at low pressure and I may as well have been pumping oxygen in there. I haven't tried a flux yet but I'll give it a try along with the gas before throwing in the towel.I've got borax and lime to try. I don't know if they'll work for magnesium but I've used them with aluminum.
NeighborJ Posted September 18, 2016 Posted September 18, 2016 OM, you don't need to give my thoughts any weight but the borax will attack the magnesium and the lime will attack the aluminum. Any time I've seen it done in videos they heat it inside a tin can and simply keep it covered the entire time except when they are charging it. It is allowed to cool in the can to prevent flair ups then the can gets pulverized with a hammer to extract the mgal. Welding rod uses two types of flux to prevent oxygen and hydrogen from getting trapped in the melt. The first kind is silicon and is referred to as lo-hy and the second is a cellulose based flux, either of these would likely keep oxygen away and with neutral acidity. I think charcoal is the easiest form of cellulose we have and if it was me, I'd add some silicon to it. This should be more than enough barrier to protect the metals underneath and it should float on top in a liquid state so as to not interfere with loading and pouring. 1
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