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Random Number posted:gently caress your instructor. Manual machining may not be as fast as CNC and can't hold/repeat like CNC but it sure as gently caress isn't holding a button and watching a cutter stir coolant. Non CNC machining is dumb and pointless for anything that isnt repair work or being a fancy drill press. There, I said it.
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Aug 3, 2013 15:43
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Xenothral posted:Disappointingly, I'm only able to find these two pictures of the chainmaille watch I made, so no build log or explanation of how mailling works just yet, but here are the pictures! (They are very large) I want to appreciate that you made something but I am just so distracted by my temptation to make fun of you.
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Sep 6, 2013 08:10
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Sagebrush posted:It does, but the abrasive is generally recoverable. You'd have to replace it eventually but the system I'm familiar with has a filtration unit that can recycle both the water and the abrasive at least over some number of hours/days. Yes you can recover the abrasive. It only gets changed cause it gets tuns of hours on it and contaminated.
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Oct 13, 2013 21:31
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Motronic posted:That's output. Inrush current of an incandescent load is super high but I would assume they use some sort of current limiting resistor on start up.
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Oct 28, 2013 01:25
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I cant speak to the stainless but the aluminum, even if anodized, won't matter. All annodizing is is making a thicker layer of the oxide it already forms instantly on contact with air. When I say thicker I mean 0.0005" thick instead of 0.0001" thick. Go ahead and polish it.
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Oct 29, 2013 05:04
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rotor posted:Attn: SF Bay Area metalworking people (are there any here?): http://sfbay.craigslist.org/sfc/tls/4192415007.html I will most likely be one in maybe 2 months.
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Nov 17, 2013 16:36
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kastein posted:Alright. If I want to cast brackets and intake manifolds and stuff for engines out of aluminum, what do I need to know? There is a book called Aluminum and it's alloys produced by the ASM in the early 80s. It will tell you everything you need to know to do this correctly and make decent quality castings, even out of scrap. It explicitly answers all of these questions and explains why. It will also make you realize how stupid most of the home casters are on the internet, for example steel crucibles are a stupid idea because iron forms really lovely, insoluble, brittle precipitates that use up the alloying elements. Here is the book, I have a photocopy of it. Maybe you can find it somewhere much cheaper...like free as a PDF. http://www.asminternational.org/portal/site/www/AsmStore/ProductDetails/?vgnextoid=64a68a1dbb874210VgnVCM100000621e010aRCRD CarForumPoster fucked around with this message at 16:00 on Nov 26, 2013 |
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Nov 26, 2013 15:50
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kastein posted:I had no plan for a crucible yet... sadly I don't have a large enough graphite block to make one out of that. This is going to require a lot of metal. Google might be able to help you find it  But seriously that book owns so hard.
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Nov 26, 2013 17:58
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Brekelefuw posted:Can anyone recommend any metallurgy books? I am specifically interested in Copper and its alloys, but I would not mind knowing a bit about steel too. How in depth do you want? The ASM is basically the best source for these...the books tend to be pricey. E.G.: http://www.amazon.com/Asm-Specialty...s=copper+alloys
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Dec 3, 2013 13:33
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Squashy Nipples posted:Do we have any machinists in the house? I need some custom CNC milling. Small job, but I'll pay decent money. There are a few but not many that are set up to take work from the forums I'd bet. If you don't get a reply here try practicalmachinist.com. If you put up a good easy to read print or send it via PM, you can get some pretty competitive prices.
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Oct 1, 2014 04:47
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Cakefool posted:I've finally come to the conclusion that the tool I really want is a mill, and luckily I can beg use of the ones at work on occasion. They have a big old Bridgeport-type jobby as well as a little 5 axis Matsuura and a massive (8x4m bed) Asquith 3 axis. Problem is though, I want to learn to mill manually first, then progress onto the cnc ones. A technical school/college Squashy Nipples posted:Thank you. A friend also sent me this link: Solidworks, NX, Autodesk Inventor, Pro-E
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Oct 2, 2014 02:10
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Karia posted:Not bad! I wish I'd found out about this over the summer, though, I probably couldn't cast until the spring, or even next summer. I'll consider it then, right now I've got access to school shops, and it's really not necessary. I love form taps, I used to do a ton of 4-40 and M3 sized holes in aluminum prototypes and that was always the way to go. Any idea why you were breaking cut taps though? If I use tapping collets (regular collets with a square EDM'd into the bottom) I can rigid tap all day with without worry. (On my Fanuc it's M29 S[spindle speed]; G84 [Params]  No chance you're using conventional tapping cycle right?
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Oct 5, 2014 17:08
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oxbrain posted:Why would you use a smaller feed for a compensating head? I always use those at the same settings as rigid. Ive never thread milled anything but those that have swear by it. I should probably start. +1 on why the heck would you run less feed on a tapping head.
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Oct 6, 2014 06:49
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Random Number posted:I'm looking at casting an aluminum bracket (about 7 cubic inches of aluminum)and I was wondering if anyone here had any experience with sand casting aluminum in a back yard environment. I do have access to a 3D printer, so I can do lost wax casting by melting out the abs. Just an FYI, expect low strength, crappy aluminum as basically all of the things that weaken aluminum (improper heat treatment, Iron intermetallics/contamination, etc.) are present in abundance.
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Oct 16, 2014 05:39
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Random Number posted:Hmm, maybe I'll only make a casting as an example of the mass produced bracket and still machine the prototype bracket. I was hoping to kill two birds with one stone, but it seems like it might not be feasible if I can't put 6061 alloy in, and get 6061 alloy out. Even if you had a crucible that wouldn't leak impurities and you cleaned off the slag on top, the difference between the 6061-O (as cast) that comes out and 6061-T5/6/65 (Solution heat treated, aged) that you buy is still massive. Same alloy: http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061O http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061t6 Cast alloys are usually considerably higher silicon than their wrought counterparts. You could probably get higher strength out of an as cast 356 alloy (think wheels, transmission housings) and it would cats better. You're still in the order of 1/4-1/3 the strength of a 6061-T6 Bar. 6061 is a really awesome alloy because its cheap, widely available, pretty high strength, easily machinable and anodizes pretty well. There's good reason its used for almost everything. CarForumPoster fucked around with this message at 16:58 on Oct 18, 2014 |
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Oct 18, 2014 16:49
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Paint or black oxide if you're worried about rust, otherwise probably not.
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Oct 19, 2014 19:33
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Leperflesh posted:I don't think the temper/heat treatment matters at all for your application, so I think you're fine. My knowledge of steel metallurgy compared to aluminum is spotty at best so take this with a grain of salt but I believe annealing requires you to be into a region of the phase diagram that causes a phase change which, in the case of steel, is the austenitic range (the A3 line in this diagram) so more like 1400*F.  Also IIRC the color of the oxidation on steels is due to thickness of the oxide layer which is going to grow significantly differently depending on alloy and conditions...that chart seems pretty meaningless as a real world marker for that. Sorry if this came off all neg nancy its after work and I am a neg nancy.
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Oct 21, 2014 02:23
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Jeherrin posted:I had absolutely hoped never to see one of those graphs again in my life. Because you hate useful things?
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Oct 22, 2014 01:42
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Ambrose Burnside posted:Is there any way to get particularly low-carbon hot-rolled steel sheet? Not real-deal wrought iron, just the most ductile steel possible. I know the steel sheet they use in transformers and the like has almost no carbon but it does have silicon which kinda defeats the whole ductility thing. How thick? Steel has the naming format of ZYXX with the XX being 0.XX% carbon. Many (most?) metal supplier have retail store where they sell drops. If you go to a metal supplier and get whatever the lowest % carbon steal they have is, it'll in general be the most ductile.*** ***theres a million caveats to this but oh well it's pretty true I think most bars/thicker sections of steel, even low carbon, contain silicon as part of the deoxidation process. (A cursory search leads me to believe up to 0.6%) Again I think, but am not sure, silicon would be in solid solution in ferrite in the common concentrations which shouldn't greatly effect the mechanical properties, like adding carbon does. Not my area of expertise though. EDIT: A different thing I read says silicon will increase strength in low carbon steels so I dont know. Also apparently it makes it lovely to machine because it messes around with size/shape of sulfide inclusions. CarForumPoster fucked around with this message at 05:50 on Oct 22, 2014 |
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Oct 22, 2014 05:41
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Leperflesh posted:Is it a spring?  Spring steel is not necessarily a low alloy steel and while they are typically in that range that is a very very big range. 5160 and 1095 are both fairly common but outside this description. You are right that its probably a spring and that it matters.
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Oct 31, 2014 04:34
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Hu Fa Ted posted:I thought I was getting somewhere TIG welding steel, I've fixed a few cracks for folks in non-essential / non-life threatening applications but aluminum TIG welding is seriously kicking my rear end. I've re-watched a ton of videos, cleaned the poo poo out of the AL with pristine stainless brushes and acetone and my welds look like poo. Pics?
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Oct 31, 2014 06:18
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Slung Blade posted:Holy gently caress how do you weld inconel plate to cast iron? That is some next level poo poo. Maybe he got it for freezy at work? I wanted a technical answer to your question of how and heres the best I got: Nickel-Base Alloys to Steels. Nickel alloys can easily be welded to steels using a suitable filler metal and proper control of dilution. Nickel-base filler metals are generally used because of their good ductility and tolerance of dilution by iron. Suggested nickel-base filler metals for welding nickel alloys to steel or stainless steel are listed in Table 23. from Table 23 N06600 INCONEL 600 COVERED ELECTRODE LCS: ENICRFE-2, ENICRFE-3 SS: ENICRFE-2, ENICRFE-3 Sulfur and phosphorus in nickel and nickel alloys cause hot cracking. The melting techniques used to produce nickel and its alloys are designed to keep the content of these elements to low levels. By contrast, the sulfur and phosphorus contents in some steels are typically higher. Consequently, dilution should be carefully controlled when joining a steel to a nickel alloy with a nickel alloy filler metal, to avoid hot cracking in the weld metal. Most nickel-base weld metals can accept a substantial amount of iron dilution, but the dilution limit generally varies with the welding process. Weld metal deposited with nickel- or nickel-chromium-covered electrodes can tolerate up to approximately 40% iron dilution. With bare nickel or nickel-chromium filler metals, however, dilution should be kept to about 25%. Acceptable limits of iron dilution for nickel-copper weld metal vary, depending on the weld process. With SMAW, iron dilution of up to about 30% can be tolerated. Submerged arc weld metal should not be diluted by more than 25%. With the gas-shielding processes, nickel-copper weld metal is less tolerant of iron dilution, especially if the weld is to be thermally stress-relieved. The maximum limits for iron dilution in a welded joint are 10% when it will be used as-welded and 5% when it will be stress-relieved. A buttering layer of nickel or nickel-copper weld metal should be applied to the steel face in order to avoid exceeding these limits. Nickel-copper weld metal has a maximum dilution tolerance for chromium of about 8%. Consequently, nickel-copper filler metal should not be used to join nickel-copper alloys to stainless steels (see Table 23). EDIT: I took this from a metals handbook, their reference is: DISSIMILAR METALS, WELDING HANDBOOK, 7TH ED., VOL 4, AMERICAN WELDING SOCIETY, 1982, P 514-547 You could probably find more and better up to date info in the current version of that book CarForumPoster fucked around with this message at 22:12 on Oct 31, 2014 |
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Oct 31, 2014 22:05
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Hu Fa Ted posted:The boy decided it need to look like a mushroom: That's aluminum, yea? In the future I'd recommend taking a finish pass at .002in depth with the sharpest tool you have. Those scratches are pretty deep and would be very difficult to sand or polish out.
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Nov 3, 2014 17:58
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Hu Fa Ted posted:Yeah, this is the first time I've used my lathe to make something nice so I'd never really paid attention to finish. I did do a finish pass at .002 but the tool I used had a nick in it apparently. I actually made the fit a little too tight, I was thinking about knocking off a thou so it fit in the basket without creating a vacuum seal. BTW Uncoated or Diamond\TiB2 coated carbide for aluminum. Most of the TiN/TiAlN coatings that come on carbide isnt good for aluminum.
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Nov 4, 2014 02:45
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Hu Fa Ted posted:This will definitely out me as a rank amateur, but I have been using un-coated C5 carbide lathe tools for basically every metal. Should I be using something else for Aluminum? For my lathe at home I used these: http://www.ebay.com/itm/5-Piece-1-2-Indexable-Carbide-Tool-Bit-Sets-C6-/150662862220?pt=LH_DefaultDomain_0&hash=item231434d58c Immediately throw out the insets, literally the worst inserts ever. I think I got some TiN coated Kennametal old stock bits on eBay for them too. MSC has 134 different options for TCMT3252 inserts, starting at $8 per. And you get 3 cutting edges with them so they're actually cheaper than those things. CarForumPoster fucked around with this message at 04:26 on Nov 4, 2014 |
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Nov 4, 2014 04:24
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Oh...yea.. Thats a real problem. If googling the part number on the holder doesnt tell you what insert it uses youre basically hosed unless you have a tooling rep come by or whanna email the company. Luckily those say they use TCMT 32.51s. The geometry of tool bits is actually a pretty standardized system, which you can also find by googling.
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Nov 4, 2014 05:27
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oxbrain posted:Unless you're doing a ton of machining it isn't worth spending too much time worrying about insert selection. TiN or TiAIN is a good all purpose coating. Great for carbon steels, pretty good with aluminum and with the right speed/feed will cut yellow metals, superalloys, composites, etc. well enough. Get used to calculating surface speeds and make notes of what works well in what materials for that insert. Pretty good advice for the home shop.
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Nov 4, 2014 06:35
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Hu Fa Ted posted:I actually have no idea how to grind a lathe tool bit. I mean, I've watched videos but that poo poo looks like some sort of dark art of touchy feely stuff. Doesn't matter, cause boy howdy, I got a new set of indexable lathe tools to try out! I know how and never do it because it is not a useful skill, IMO. Congrats on the welding progress. I recall welding a 356 alloy wheel and laying down beads on it was easier than I though it'd be. Not having to worry about burning through because it was a thick section made my life easier.
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Nov 8, 2014 03:51
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No wastes of time, just ~learning experiences.~ What does it look like now that its done?
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Nov 8, 2014 18:13
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rotor posted:no I mean you said HSS sucked what should I be using Carbide.
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Nov 8, 2014 18:44
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rotor posted:I have a very small, low power taig lathe and have heard people say that sharp HSS bits are better for low power high speed applications is this true or have I been hoodwinked? Better than coated carbide, possibly because of the edge blunting that occurs with PVD coatings. Better than uncoated carbide? I can't see any reason why that would be. Especially when you can use indexable inserts from reputable manufacturers. (Because theyll have a highly capable production process to control tungsten carbide grain size in the cobalt...hopefully) Also nothing about that lathe is "high speed" in any sense in the modern machining world. (I am assuming a sub-20,000 RPM spindle) Also, I am of the opinion that hand grinding stuff is for suckers unless you need an endmill like oxbrain posted above. But for your every day lathe bits? Screw that. The only exception is that I use an HSS part off/grooving tool cause the insert ones often dont go deep enough and only have two edges, and its super easy to grind those. CarForumPoster fucked around with this message at 22:09 on Nov 8, 2014 |
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Nov 8, 2014 22:07
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Motronic posted:OK, great. I've got a friend-of-a-friend who does this professionally, so I'm sure I can get him to come by and show me what's up if necessary but in the mean time I wanted to find some good resources for settings, what rod I should be using with what, electrode shape (and maybe what electrodes.....I don't even know if there are different materials or diameters), and pretty much all that kind of basic stuff. There is a ton of information easily found by searching, but a lot of it seems to have a healthy dose of "because this is the best way" where those "best ways" don't agree with each other. And other sites are obviously just trying to sell me DVDs. I don't know what to trust. I found this to be helpful: http://www.amazon.com/Welders-Handb...rds=tig+welding
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Nov 9, 2014 19:59
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Youre talking about 80/20? Or just literally any aluminum that is extruded?
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Nov 30, 2014 19:09
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Karia posted:Try McMaster. They sell a decent assortment, in both metric and imperial. I love McMaster but they're $$$$. You get what you pay for as an engineer (fast shipping, cad data, etc.) but for a hobbiest... I'd bet that the Chinese make a knock off that is sold on eBay or Alibaba/AliExpress. Also try google shopping and sort by price. You can use McMaster to come up with a list of what you need then order it there. EDIT: Yep. http://www.aliexpress.com/wholesale?catId=0&initiative_id=&SearchText=aluminum+extrusion CarForumPoster fucked around with this message at 19:43 on Dec 1, 2014 |
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Dec 1, 2014 19:41
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sixide posted:It's not dying out, it's completely dead. This is why toolmakers/model shop techs/prototype machinists are worth $$$ and are hard for factories to find (outside of certain small areas). Manual machining as your only job might be dead but manual machines are still in every machine shop for good reasoon. Just might only be 1-2 of each type for every 10 CNC machines.
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Dec 11, 2014 04:20
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Has anyone used the ESAB Rebel 215ci combo MIG/TIG. It seems to have good reviews over the net. I am tasked with spec'ing one for a makerspace and am planning on using it for both aluminum and steel projects. It seems to have a lot more feature/amperage than anything in it's range. Since it is a DC Tig only, the aluminum would be done by MIG with a spool gun. Any thoughts? https://www.amazon.com/Esab-Rebel-EMP-215ic-0558102240/dp/B01BXDOENG/ref=sr_1_1?ie=UTF8&qid=1469975236&sr=8-1&keywords=ESAB+Rebel
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Jul 31, 2016 15:29
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honda whisperer posted:I've always used 25/75 co2/argon for the mig and 100% argon for tig. Are you planning on two tanks or will one work ok for both? I was planning argon for both.
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Aug 3, 2016 00:04
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Mr. Bill posted:A co2 mix is Bad News Bears for aluminum welding, I'm afraid. It's great for heat transfer on steel (even better, if you can afford it, is helium mix) but if you try to weld aluminum with a co2 mix you mostly just get horrible black soot all over your expensive checkerplate. At work we keep co2/ar for steel, pure ar, and ar/he for thick aluminum. Pure AR is probably best bet if you can only get one tank, but you'll have lower heat capacity on steel. If all you're doing is steel, try to get TriMix (ar/he/co2). Is this a reply to me? As stated I am welding both aluminum and steel. Also it's a fablab so probably very little in the way of thick stuff.
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Aug 3, 2016 00:08
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kastein posted:Speaking from experience, welding steel with 100% Ar is miserable. Get 75/25 for that, seriously. I'd rather run fluxcore than 100% Ar MIG. I have TIG'd a hobbyist amount of steel with 100% Argon and it was fine. Why do you claim it should have been miserable?
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Aug 4, 2016 00:56
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Brekelefuw posted:How well do you guys think anodizing would hold up to heat and flux from soldering? The ASM handbook on welding, brazing and soldering doesn't note any issues with damaging the ano layer that I found in a quick search. Speculation based in some scienceish knowledge: If it is something like 6061 or any of the lower transition metal content alloys (i.e. not 2XXX or 7XXX) that has been through desmut before a Type II ano, pretty well. Type 1 (chromic acid) I dont know. Type III (aka hard ano) is more likely to have issues. Less thermal shock is better. No idea about the whetting of braze to various ano'd surfaces. For corrosion inhibition ano'd actually seems much much better because it will inhibit galvanic corrosion between the copper and aluminum. (Or, potentially, whatever filler metal you have) EDIT: You could also hit the surface with a clean SS brush or sand it then poof, no more ano. EDIT2: Apparently whetting is not good because successful brazing involves the formation of alloys of the braze material and base material at the interface. I dont know of any interfacial oxide alloys so I'd guess you should probably remove the ano in the area of brazing. quote:Oxide layers inhibit wetting and spreading, as do grease, dirt, and other contaminants that prevent good contact between the brazing filler metal and the base metal. One of the functions of a flux the oxide layer on the joint area and thereby expose clean base metal. CarForumPoster fucked around with this message at 14:23 on Aug 6, 2016 |
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Aug 6, 2016 05:42
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