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Splizwarf posted:I didn't pick it, guy wants spring steel for a Wisby-style coat of plates for Battle of Nations. v Double-posting for a change in subject.  1650F = ~900C. What you are doing when you raise the steel above the austenetic temperature, is you're melting all of the pearlite/ferrrite/cementite crystals that are formed in the alloy. As soon as all of the metal has reached austenitic temp, that process has completed. You then quench to freeze the metal so quickly that there is no time for those crystals to re-form. Instead, you get a fine-grained structure called martensite, which is much harder (and more brittle). The speed at which you quench determines how much of that you have in the matrix, so you can quench faster or slower using different quenching baths - oil and water are both common.  There is no point to holding the metal at the high temperature. Nothing happens over time. All you are doing is wasting energy and fuel. Unless you're dealing with some exotic alloy where something really does happen at 900C, which could be the case - I am not a (forensic or otherwise) metallurgist. But if you're dealing with a normal carbon steel alloy, once all of the metal is at temp, you're good. (A recipe for heating a gigantic metal ingot might ask you to leave it in a 900 degree forge for an hour, but that's to ensure all of the metal is up to temp.) The temper, on the other hand, is a process where you soften the too-hard quenched metal by bringing it up to a specific temperature, at which a specific balance of pearlite vs cementite/ferrite crystals form. Here, time is important because you want the entire work piece to reach the exact temper you wanted, and you're heating using air that is exactly at that temperature. Put a chunk of metal in a 500 degree oven and it may take an hour or more to get up to 500 degrees. Note that 500F is 260C:  This chart is only for plain carbon steel. 500F is hot enough to bring down the brittleness to a point where the metal is no longer "glass hard" - a glass hard blade will shatter when dropped on a hard surface, it's so brittle - but still have lots of hardness left, which for example is great for keeping a honed edge on a blade. I'm going from increasingly poor memory, so forgive me if I got anything wrong here; but I'm thinking it's likely that the recipe you're working from imagines you're heating very large pieces of metal, and thus needing to put them in a very hot forge or kiln for an hour just to be sure the entire piece is heatsoaked. For something smaller, less time is needed. e. There's a pretty decent writeup of this stuff in wikipedia. See: Heat Treating Quenching Tempering (metallurgy) Austenite Martensite and if you're into advanced interrupted quenching: Austempering Bainite There is an iron metallurgy rabbit hole, and it's deep. Don't fall in! Leperflesh fucked around with this message at 19:56 on Dec 3, 2015 |
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Dec 3, 2015 19:34
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Killer information . I got some fire bricks ,so hopefully I can get my pieces up to temp when I try it again. On the other hand, my lathe is really struggling to cut threads in the to steel, so I have to figure that out before I can heat treat. It cuts the steel fine, but threading causes it to slip in the Chuck. I have an idea to fix it though.
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Dec 3, 2015 22:53
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Leperflesh posted:Double-posting for a change in subject. From looking at that graph for a few minutes, I've come to a conclusion. For the vast majority of tool steels that the vast majority of smiths are ever to work with, (between A and B) the Magnetic point is so close to where Austenite formation is complete that it might as well be the same? Between A and B, the temps are within 100F of the Austenite line. If that piece stays in the forge for a few seconds past non magnetic, it's guaranteed to be hot enough to reach maximum hardness in a proper quench. Yes? As an aside, is the non-magnetic point really a constant? Even regardless of carbon content? Also, how different does this graph look for various alloys? Leperflesh posted:There is an iron metallurgy rabbit hole, and it's deep. Don't fall in! I find this fascinating, and I realize my skills are getting high enough that this will start to matter. Any good youtube videos you recommend on this subject?
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Dec 4, 2015 01:08
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Pagan posted:As an aside, is the non-magnetic point really a constant? Even regardless of carbon content? Also, how different does this graph look for various alloys? Heh, that's a phase diagram. It's a very simplified chart of phases for a given binary alloy at equilibrium. This means your alloy is pure, at a homogenous temperature, and the kinetics of phase changes have had sufficient time to come to equilibrium. The kinetics are why you soak at temperature to completely austenitize. The binary phase diagram doesn't take into account any additional alloying elements, but steel alloys are heavily dependent on carbon content. Various alloying additions can stabilize phases, allowing them to exist at temperatures and/or iron:carbon ratios they wouldn't in the binary system. Thus, the non-magnetic point is not a constant; it can change depending on what alloying elements are included to alter the stability of ferrite (the microstructural constituent that has magnetism). Want to go for a trip? Look up some trinary and further phase diagrams. They're readable, but barely. Also check out the wiki on phase diagrams. Forgive me if I've misremembered anything. It's been a while since my alloys class. I used to be able to reproduce that phase diagram from memory!
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Dec 4, 2015 01:26
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Thanks for the effortpost, this is fascinating. I want to know all the things.
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Dec 4, 2015 08:03
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If you don't follow Clickspring on youtube, you should because everything he does is gorgeous. https://www.youtube.com/watch?v=uST7iJgC_gs This box is amazing.
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Dec 4, 2015 22:24
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Brekelefuw posted:If you don't follow Clickspring on youtube, you should because everything he does is gorgeous. I saw his fire piston video on Make's channel - https://www.youtube.com/watch?v=UvCB3_KtSz0 Unf. I want a lathe.
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Dec 4, 2015 22:42
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Pagan posted:From looking at that graph for a few minutes, I've come to a conclusion. For the vast majority of tool steels that the vast majority of smiths are ever to work with, (between A and B) the Magnetic point is so close to where Austenite formation is complete that it might as well be the same? Between A and B, the temps are within 100F of the Austenite line. If that piece stays in the forge for a few seconds past non magnetic, it's guaranteed to be hot enough to reach maximum hardness in a proper quench. Yes? Yeah, pretty much. I want a piece to be non-magnetic and then I leave it in for maybe another 30 seconds. I've only worked with a large, gas-fired forge, though. With gas, scale buildup is an inescapable problem, so you want to get your piece out as fast as you can to minimize scale. Your mileage may vary. quote:As an aside, is the non-magnetic point really a constant? Even regardless of carbon content? Also, how different does this graph look for various alloys? Lawnie touched on this, but basically; no, everything I've said is a simplification, and that chart - despite having a lot of density of information - is also a simplification. Like I said, the rabbit hole is deep, man. Charts like this are useful as rules-of-thumb for your normal blacksmithy-type operations, which is why I posted it. For practical purposes, if you're just trying to harden and temper medium-carbon tool steel, you can use it as gospel. Give everything a little slop just to be sure, and you're good. But if you've got tungsten carbide alloy, atypical molyebdenum content, air-hardening alloy, you're making scientific instruments, planning industrial processing, or just want scientific accuracy? Then no, I'm sure none of the apparently-straight lines on that chart are actually straight lines for reals in all cases, there's probably a different phase diagram for every different conceivable alloy, probably atmospheric pressure and gravity both matter, I bet weird things happen if the metal is physically shocked at certain phases, and there's probably plenty of unwritten doctoral theses yet to be developed by metallurgical science as we continue to explore the edge cases, toss various elements into the mix, discover poo poo like buckyballs and nanotubes (but with iron I guess?), etc. quote:I find this fascinating, and I realize my skills are getting high enough that this will start to matter. Any good youtube videos you recommend on this subject? Dunno. I mostly learn this stuff (heh, "learn" ... maybe I should say "repeatedly re-familiarize myself and then rapidly forget") from textbooks and wikipedia. If you come across some, link them, though! Leperflesh fucked around with this message at 23:15 on Dec 4, 2015 |
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Dec 4, 2015 23:13
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I'm temping at a metal supply house for the next month or two. Bandsaws cuttin' up foot thick round bar like it ain't no thang. Gonna go buck wild on the offcut room 
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Dec 5, 2015 00:33
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Ambrose Burnside posted:I'm temping at a metal supply house for the next month or two. Bandsaws cuttin' up foot thick round bar like it ain't no thang. Gonna go buck wild on the offcut room Hook a brutha up!
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Dec 5, 2015 05:55
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Ambrose Burnside posted:I'm temping at a metal supply house for the next month or two. Bandsaws cuttin' up foot thick round bar like it ain't no thang. Gonna go buck wild on the offcut room Sleepover at Ambrose's house. I'll bring a dually with a gooseneck to help you clear out some of those "scraps."
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Dec 5, 2015 15:19
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"lift up to 60 lbs" was a goddamn lie and the work is aggravating an old injury something fierce so i may not be long enough for it to use/abuse the resources but We Shall See
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Dec 6, 2015 21:06
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Ambrose Burnside posted:"lift up to 60 lbs" was a goddamn lie and the work is aggravating an old injury something fierce so i may not be long enough for it to use/abuse the resources but We Shall See gently caress 'em, grab a lift buddy. If no-one has the time then the job ain't getting done. If they fire you for not wanting to violate occupational safety laws, litigate. (Lift buddy for anything over 40# if I remember OHSA laws right, if canadian, S.O.L.)
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Dec 6, 2015 23:11
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Tonight on "Holy gently caress, I Haven't Made Anything in Months" Theatre, I make a thank you gift for a guy who let me turn living creatures into future sausage on his land. The welds holding these things together are garbage. I made them to be steak brands, and drat they're tiny. No room to get a welding rod in there, let alone start a good arc. Wish I had my MIG working.  I don't know why but I love these little curled up pigtail-wrapped handles, and the little twisted round accent just does it for me for some reason.  My first ever pineapple twist, not very good but I found it laying in some pile of scrap and old unfinished things. Decided this was a good way to use it.   Not bad. Hope he likes them. The brand testing wall grows larger. 
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Dec 7, 2015 05:49
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Brekelefuw posted:If you don't follow Clickspring on youtube, you should because everything he does is gorgeous. RIP my productivity
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Dec 7, 2015 22:48
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Pro tip: never let your friends at work know you're good at anything. Brought in those brands so my buddy could deliver them to his brother in law and guys were like "Holy poo poo, can you make me some of those?" And of course, they have the letters most difficult to render in iron because why wouldn't they?   On the plus side, I finally hooked up my mig, even managed to thread the wire on the first attempt never having done it before, ever. No bird's nests!
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Dec 8, 2015 05:35
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Rapulum_Dei posted:RIP my productivity I should have followed your warning. I don't even want to make a clock. But I can't stop watching.
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Dec 8, 2015 16:38
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Gegil posted:I should have followed your warning. I don't even want to make a clock. But I can't stop watching. Empty quoting is probably not allowed, right? I can never remember.
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Dec 8, 2015 22:19
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Gegil posted:I should have followed your warning. I don't even want to make a clock. But I can't stop watching. Yeah, I watched the tools/etc videos all in one sitting and then the clock videos in another, continuous sitting. Does anyone know how regularly he posts videos? Also, these videos have inspired me to get off my rear end and actually start building some stuff. So thats nice.
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Dec 8, 2015 22:33
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He was posting one of two a week, and then took about a month off and just started posting again, with 4 this week.
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Dec 9, 2015 03:31
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Slung Blade posted:The welds holding these things together are garbage. I made them to be steak brands, and drat they're tiny. No room to get a welding rod in there, let alone start a good arc. Wish I had my MIG working. 1/16" 6010 or 6011! It's so drat small that it's pretty easy to get a real weld in something tiny like that. Extremely versatile for little parts. Mig is so cold at initial strike that it's likely worse when it needs to actually be strong with a very small area to weld.
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Dec 9, 2015 04:35
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Hypnolobster posted:1/16" 6010 or 6011! It's so drat small that it's pretty easy to get a real weld in something tiny like that. Extremely versatile for little parts. I used tiny 6011 for the first two, mig for that one yesterday. Had to learn to mig all over again, so to speak, I've done maybe 5 minutes of actual mig welding in my life so far.
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Dec 9, 2015 04:56
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OA all the way for tiny welds like that. Where you can't get a straight rod in, you can usually manage to get a flame. I think. I mean, I'm told, I haven't done it.
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Dec 9, 2015 19:13
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So I've been heckled into the rose making business this winter for Valentines, but I don't really want to leave them "raw" this time as my remaining tester has developed a spotty rust patina and looks sort of cancerous rather than cool. Since people are buying these, I don't want them to degrade.   Any suggestions for paint which would adhere well to semi-scaled steel? I'm thinking a crimson spray enamel followed up by a light clearcoat, with the stems being oil quenched to inhibit corrosion without painting? Rime fucked around with this message at 23:27 on Dec 9, 2015 |
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Dec 9, 2015 23:00
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Leperflesh posted:OA all the way for tiny welds like that. Where you can't get a straight rod in, you can usually manage to get a flame. I think. I mean, I'm told, I haven't done it. Ehhhnnnnn. I actually fabricated two sword crossguards a couple weeks ago (long story, I literally actually can't talk too much about it 'cause of murky NDA stuff but its nothing exciting) and had to use O/A but the flame hates burning properly in tight confines that don't vent easily. It was super frustrating 'cause the torch would go out just as I got everything molten for the umpteenth time when I knew I could just shoot MIG wire in there without a care in the world and the tight confines would actually help trap shielding gas instead of loving me up. O/A generally IS very good for small stuff, and would probably be just fine for that, but ~not necessarily~
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Dec 10, 2015 01:30
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Good to know. My OA rig has been gathering dust in my garage for longer than I want to guesstimate, and I haven't gotten my new-to-me 110v fluxcore/Mig rig up and running yet, so I'm pretty horribly out of practice. I do think though that OA has a role to play in the small metal shop that a lot of people forget about because the zapgun is so convenient and easy.
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Dec 10, 2015 01:34
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OA is god-tier for welding sheet metal, thin plate and really small stock, and then the bigger you get the stupider and less effective an approach it is. It's still incredibly useful for your odd-job spot-heating and bending and brazing and cutting, much more so than actual welding, to the point that my father- been in construction his whole life, works alongside welders every day- had no idea you could actually weld anything with oxyfuel equipment, he thought it was just for cutting and applications where you need A Torch, But More.
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Dec 10, 2015 02:33
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Rime posted:So I've been heckled into the rose making business this winter for Valentines, but I don't really want to leave them "raw" this time as my remaining tester has developed a spotty rust patina and looks sort of cancerous rather than cool. Since people are buying these, I don't want them to degrade. Dip it in vinegar for a week, then heat it up to a black heat and beeswax it. Wipe away the excess.
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Dec 10, 2015 06:04
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I owe you guys some words on single crystal manufacture, but in the meantime, if any of you have read Cat's Cradle, the mechanism for Ice-9 is theoretically similar to how it's done irl. Real post with science this weekend.
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Dec 11, 2015 04:33
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So, I want to get into lost wax casting because there's just too many drat times I've needed something just so but can't really make it in my wood shop. I'm going to try and repeat the somewhat popular tutorial here: https://www.youtube.com/watch?v=hHD10DjxM1g and if things go well and I get a couple pours in and find it's something I enjoy enough to do right I'll upgrade to something larger. Any advice on this? Am I about to make something useless or will it at least be good experience when I go to do something better? Total price is like $50, all in with what I can scrounge.
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Dec 11, 2015 15:04
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Anubis posted:So, I want to get into lost wax casting because there's just too many drat times I've needed something just so but can't really make it in my wood shop. I'm going to try and repeat the somewhat popular tutorial here: https://www.youtube.com/watch?v=hHD10DjxM1g and if things go well and I get a couple pours in and find it's something I enjoy enough to do right I'll upgrade to something larger. Any advice on this? Am I about to make something useless or will it at least be good experience when I go to do something better? Total price is like $50, all in with what I can scrounge. I'd like to hear about this, too. It's getting about time for me to remake my propane forge, plus I'd like to have something that could melt steel (melt it enough to make wootz or crucible steel, at least) I've heard that if you blend clumping cat litter, it's made of the same stuff fire bricks are made of, and mixing it with plaster and sand will give an excellent castable refractory. This video makes it look pretty easy.
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Dec 11, 2015 17:11
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Silversmithing must be a pretty popular hobby these days since I have been spending the last couple of months making ring mandrels for friends, I made a heap of these tapered ones out of some scrap boiler rod, the old beat up one I had there for a pattern has about a 3 degree bend in it.  I buggered up the first one of these stepped ones pretty badly  but I am happy with how the bottom one turned outall 13 steps are within +- 0.18 mm tolerance, tedious work when your lathe has unmarked hand wheels, I have no idea what sort of steel the dude gave me to make them out of but it ate up my hss bits and blunted two hacksaw blades I used to part them. I also gave my busted fan a new set of blades. 
coldpudding fucked around with this message at 10:54 on Dec 15, 2015 |
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Dec 15, 2015 08:37
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Random Number posted:gently caress 'em, grab a lift buddy. If no-one has the time then the job ain't getting done. If they fire you for not wanting to violate occupational safety laws, litigate. (Lift buddy for anything over 40# if I remember OHSA laws right, if canadian, S.O.L.) you will be shocked to know that the floor manager forbade me from wearing hearing protection because it makes it harder for him to get my attention, who could have ever guessed these guys arent too stringent about safety
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Dec 16, 2015 00:49
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Pagan posted:I've heard that if you blend clumping cat litter, it's made of the same stuff fire bricks are made of, and mixing it with plaster and sand will give an excellent castable refractory. This video makes it look pretty easy. It produces a "technically usable" castable refractory but it's nothing you actually want to use if you have the choice. Cat litter is bentonite clay, firebricks are alumina. Both are heat resistant but clay/plaster/sand has no significant insulating value whereas porous alumina does. Your homemade refractory will retain heat just fine and will survive the heat okay but will produce a smelter that consumes so much more fuel to do its job than it ought to. For reference, the rule of thumb is that hard structural firebrick absorbs twice as much energy as soft insulating firebrick does. Therefore, a non-insulated smelter will use at least twice as much fuel to do the same work, and do that work far slower- and I'd bet the inefficiency is even worse than the hard/soft firebrick thing, because hard firebrick is still manufactured with an eye to having -some- insulating ability. Really dense homemade refractories without an organic burnout component added to improve R-value are just enormous heat-sinks.
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Dec 16, 2015 01:02
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 mediocre picture i finally took of a thing i made earlier this year, i dont remember if i posted other worse pictures before
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Dec 16, 2015 04:46
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Pagan posted:I'd like to hear about this, too. It's getting about time for me to remake my propane forge, plus I'd like to have something that could melt steel (melt it enough to make wootz or crucible steel, at least) Made it last weekend, Ambrose has the basic idea. It all appears to be very functional but not really heat efficient since the outside gets rather warm. Still for $50-60 all in, not terrible if you aren't doing much. Not like charcoal is really expensive or anything. I got a quick question about scrapping hard drives for aluminum to melt if someone happens to know, since I have roughly 40 of them. I'm pulling the bottom and inside aluminum ring. I've been told that the platters themselves are aluminum (although they can apparently also be glass, so I'll have to check each one) with a very thin palladium coating. If I'm just making random poo poo out of aluminum is there any big issue with melting the whole thing down or is that tiny foil of palladium something I'm going to have to deal with first because it's going to screw something up? Seems like most people scrapping these things are trying to recover the palladium so I cant tell.
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Dec 16, 2015 07:07
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Cheapest option for aluminum is going to be ruined aluminum alloy car rims. When I worked in a salvage yard we had a guy whose full-time job was to run a rim smelter, skimming slag and pouring aluminum ingots the size of of small microwaves. Considering that we sold intact functional rims for as little as $25, ruined ones should be a lot cheaper. If you have a bunch of harddrives and are looking for things to do with em, nevermind. v  v
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Dec 16, 2015 08:18
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Ambrose Burnside posted:
I still love this thing. :3
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Dec 16, 2015 10:44
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Got to play with a power hammer for the first time. https://www.youtube.com/watch?v=GF5a8Q5pGZc Not much to the video, just me messing around with some square stock. I can tell it's going to take some practice to get the hang of, but on the other hand, this is awesome.
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Dec 18, 2015 06:49
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Splizwarf posted:Cheapest option for aluminum is going to be ruined aluminum alloy car rims. When I worked in a salvage yard we had a guy whose full-time job was to run a rim smelter, skimming slag and pouring aluminum ingots the size of of small microwaves. Considering that we sold intact functional rims for as little as $25, ruined ones should be a lot cheaper. Agreed. One wheel is probably more than you'll get out of a couple dozen hard drives. That being said, if you want to smelt the hard drives for fun, here are some things to remember: - using some flux will probably get most of the magnetic coating and all the garbage from the stickers, paint, powdercoat, etc on the main housing castings out of your finished melt - some of the housings might be magnesium not aluminum. I don't know how to check but your life will become very interesting if you find out the wrong way when a magnesium one catches fire. I don't know what flux people generally recommend, but IIRC a zinc chloride based plumbers flux I used while melting 6000 series extruded aluminum punch-out waste as a kid seemed to work well. It might have added some zinc to my alloy, or released toxic smoke, I have no idea, I stayed out of the smoke because I did my smelting using a crucible made from black steel/iron pipe held in the center of a campfire.
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Dec 18, 2015 18:43
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