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You always wanna start the melt with a smaller quantity of good, clean metal, preferrably in 'chunks/blocks' with a small surface area. establish a good hot melt puddle, and then add additional (pre-heated, moisture free!) scrap directly to the melt puddle, piece by piece without 'overloading' the smelter or freezing the puddle. the main concern here is oxidization- thin-profile metal will oxidize very aggressively in the hot blast of a smelter, which you want to limit as much as possible. instead let the heat of molten metal rapidly melt as much of the total charge as possible, with as little exposure to the smelter atmosphere as you can manage. the classic example for hobbyists is melting aluminium cans: they're a huge pain in the rear end because they're incredibly thin, a can placed in a 'dry' smelter will just oxidize completely through the metal and turn into garbage slag/dross without melting at all. On the other hand, a thick slab of aluminium chucked in a smelter will retain the large majority of its mass internally as aluminum and not oxide alumina until it melts, and those thin cans added directly to the puddle will be protected from the smelter atmosphere and melt much more rapidly due to the better heat conduction of liquid metal, largely avoiding the alumina oxidation issue.
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Sep 26, 2020 20:28
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Attempting my first pair of tongs, had a brain fart when doing the twisting but I think I can make something usable from these.   edit: resized photos, was phone posting, stuff looked a lot bigger on the screen. His Divine Shadow fucked around with this message at 18:45 on Sep 27, 2020 |
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Sep 27, 2020 14:18
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I do the former with the remaining material sitting on the lid heating up so they don't freeze the liquid when you set thm in.
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Sep 27, 2020 14:37
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wolrah posted:At the moment the most complicated thing I'd like to do with it is repairing some damage to my lawn mower and maybe building a basic go-kart type chassis for a gas powered Power Wheels hack. Should this be able to get the job done? The main complaint I see on these is the quality of the wire. If you are having issues I'd grab a small spool of Miller/Hobart/Lincoln wire and see if that helps. If you do end up upgrading to a gas machine flux wire is still useful for outdoor repairs if it is too windy for gas shielding so there is a (small) chance you may actually use it.
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Sep 27, 2020 17:38
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Cast some aluminum today. Need to work on my tamping / green sand skills. I was afraid I'd shift the pattern as I tamped it so it wasn't tight enough. Some of my finer details fell out. All in all the burner worked well, not sure I can get much past aluminum for now. I tried to melt some copper and make aluminum bronze but it stalled half way through the melt. I cast it anyway but it cracked (not enough copper) and looks like a metal potato. The petrobond was a solid win, very glad I got the good stuff. I've got a good idea of what to try next, so hopefully V2.0 will turn out better.
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Sep 29, 2020 02:06
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I just posted in the tools thread as well but I'll post the tldr here: Got a free mig from a guy at work coming on Friday, it's about 15-17 years old but hasn't seen a ton of use. Gas and gasless use. Any suggestions on stuff I should be looking at in terms of replacement or maintenance?
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Sep 29, 2020 13:22
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The wire feed and nozzles, mostly. The guts of a mig is complicated enough that it's uncommon to work on those parts yourself, also as it's mostly circuitry and electronics stuff if something's broke you're usually replacing that specific part. And usually with the insides it's very binary that either it runs or it don't. The most common mechanical fault though is a wire jam, so making sure the wheel runs smoothly and knowing how all the pieces that hold the wire and feed it work, so that way you know what to fix if it kinks. At the top you will occasionally be taking apart the nozzle assembly, as the cup will crust up and need to be cleaned (just nibble at the build up with needle nose pliers), and the tip itself gets replaced every once in a while, it's more or less a consumable, just one with a longer work life. We ran the poo poo out of ours and they were all older units, though not that old. If it wasn't used much you should get good life out of it as long as the insides work. threelemmings fucked around with this message at 13:44 on Sep 29, 2020 |
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Sep 29, 2020 13:37
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This may be the wrong place to ask this, but I think you're the folks most familiar with machine screws and threads. I'm trying to track down a screw (literally only need one) for the hinges on my front door. I've matched up the thread using a thread gauge tool, and it came out as a 24G 55º Whitworth thread (I think aka British Standard Whitworth or BSW). All the machine screws I have are metric, and all the ones I can find at any reasonable price are also metric. Is there something I'm missing, or am I going to have to spend £100 on a box at a specialist somewhere? 
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Sep 29, 2020 13:39
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Jaded Burnout posted:This may be the wrong place to ask this, but I think you're the folks most familiar with machine screws and threads. What is the major diameter of the threads? Is it exactly 4.5mm?  A #9 thread would be almost exactly 4.5mm OD, and while rare today it did exist in a 24, 30 and 32 TPI versions. edit - randomly found thread chart : 
Yooper fucked around with this message at 14:02 on Sep 29, 2020 |
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Sep 29, 2020 13:54
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Jaded Burnout posted:This may be the wrong place to ask this, but I think you're the folks most familiar with machine screws and threads.
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Sep 29, 2020 14:02
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Yooper posted:What is the major diameter of the threads? Is it exactly 4.5mm? I don't know the terminology very well, I'm afraid, but 4.5mm was what I measured with 0.1mm precision calipers placed on the outside of the threads (not the shank that the threads "sit" on). Kaiser Schnitzel posted:Have you tried contacting the hinge manufacturer/door supplier? They'd be my first call. Otherwise there are specialty screw/threaded fastener suppliers that should have something. IDK what the british term would be, but 'screw supplier' on google maps pulls up those kinds of places for me. In my experience they are happy to sell small quantities. You might say you need 10 instead of one, but I have definitely bought $.43 worth of screws before and nobody was mad at me. So, the majority of screws sold here are metric these days. There is a local fixings place called "fixings warehouse", but honestly I've had limited luck finding what I want there, and I don't know how open they are right now with the covids. They're top of my list for a maybe, though. As for the hinge/door, I did think about that, but I'm not actually sure who the manufacturer is, and that would require some research. There were at least 4 people between me and the manufacturer, the first couple of layers of which I don't speak to on account of they're pricks. But it's an option, yeah.
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Sep 29, 2020 14:52
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Jaded Burnout posted:I don't know the terminology very well, I'm afraid, but 4.5mm was what I measured with 0.1mm precision calipers placed on the outside of the threads (not the shank that the threads "sit" on). Is this a really really old piece of door hardware? Your measuring method is correct for the tools you'll have. It's entirely possible that the thread is 4.76mm but worn down to 4.5mm. The other option is to tap it out for something metric sized that you can get locally.
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Sep 29, 2020 15:55
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threelemmings posted:The wire feed and nozzles, mostly. liner too. If it's original and has a lot of hours on it it's probably time. Definitely replace it if there's any binding on the wire feed, especially when you have the cord in tighter bends.
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Sep 29, 2020 16:29
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Yooper posted:Is this a really really old piece of door hardware? My guess would be its a 3/16-24 screw, if not it may be close enough to work anyway.
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Sep 29, 2020 19:15
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Tapping for a metric screw might be an option.
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Sep 29, 2020 19:24
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Just checked machinists handbook. You've got a 3/16-24 bsw bolt. A #10-24 should work as replacement. You might need to sand the tops of the threads off to make it fit though. You could get up to 5mil interference otherwise depending on how worn the female threads are.
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Sep 29, 2020 19:38
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The whole shebang, door, frame, and hinges, are about 2 years old.
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Sep 29, 2020 19:58
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Jaded Burnout posted:The whole shebang, door, frame, and hinges, are about 2 years old. Is it a hex head too? A pan head hex drive #10-24 may be harder to find than the bsw you have.
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Sep 29, 2020 20:04
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Samuel L. Hacksaw posted:Just checked machinists handbook. You've got a 3/16-24 bsw bolt. A #10-24 should work as replacement. If it is that thread then you can get them here, they have all the weird threads https://www.stainlessautomotivefastenings.co.uk/index.php?main_page=index&cPath=566_116_598_514&zenid=q3cg3k55f42ji4ior572o1n9v3
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Sep 29, 2020 20:23
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Samuel L. Hacksaw posted:Is it a hex head too? A pan head hex drive #10-24 may be harder to find than the bsw you have. Phillips. I've gone and sent an email to a possible supplier. They have BSW screws that are close, and cheap, so hopefully they can steer me right. Thanks for all your helps 
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Sep 29, 2020 20:27
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echomadman posted:If it is that thread then you can get them here, they have all the weird threads Oh nice, thanks. Apparently I've been to that site before, I must've stumbled on it while looking but not had enough information to understand what I was seeing.
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Sep 29, 2020 20:29
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BSW machine screws are still used in new products?! I know it's used in some weird specific applications but on brand new stuff that's sort of mindblowing.
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Sep 29, 2020 20:39
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Hypnolobster posted:BSW machine screws are still used in new products?! I know it's used in some weird specific applications but on brand new stuff that's sort of mindblowing. To be fair, this adventure has me discovering more thread types than I have thread gauges for, so maybe it's a BA thread or even UNC, but the BSW gauges were pretty drat spot on.
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Sep 29, 2020 20:41
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Jaded Burnout posted:To be fair, this adventure has me discovering more thread types than I have thread gauges for, so maybe it's a BA thread or even UNC, but the BSW gauges were pretty drat spot on. BA, and BSW as well as BSB are still used in model steam engines. Blackgates Engineering will have most sizes in stock. Not sure who would have them in the USA. For that kind of thing, I usually order from the UK. Oh, British sports car specialist places should also have BA bolts. They used them quite a bit.
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Sep 30, 2020 00:07
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I also am astonished that people are still using anything other than metric or US customary in new designs anywhere in the world.
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Sep 30, 2020 01:42
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Sagebrush posted:I also am astonished that people are still using anything other than metric or US customary in new designs anywhere in the world.
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Sep 30, 2020 04:52
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stik posted:BA, and BSW as well as BSB are still used in model steam engines. Blackgates Engineering will have most sizes in stock. Not sure who would have them in the USA. For that kind of thing, I usually order from the UK. Fortunately that's where I am!
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Sep 30, 2020 07:03
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My new mate Kev at a screw and other fixings supplier reckons it's a 10-24 UNC so good work eagle eyes! I have some on order.
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Sep 30, 2020 17:58
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Jaded Burnout posted:My new mate Kev at a screw and other fixings supplier reckons it's a 10-24 UNC so good work eagle eyes! And they're a perfect fit. Thanks all
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Oct 2, 2020 17:28
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Finally got the tongs done, not that happy with them but I guess the first pair are never gonna be the best: The rivet is an M8 bolt, all I had, shoulda been a bit longer. I had it in the forge to get rid of the zink coating first. I think I could turn some nice rivet blanks on the lathe from bigger M10 bolts.  Also found some spring steel (a whole bunch, 8mm ish) and I made a chisel and punch from it.  On to the next pair of toongs soon, perhaps some hooks in between. For the next pair I will use thicker material, 10mm plate I think.
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Oct 5, 2020 06:27
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For a first pair of tongs, those are excellent. Well done and nice job.
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Oct 8, 2020 06:19
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Figure it's about time for me to learn how to weld (mig) ; what're some recommendations on good starting gear?
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Oct 11, 2020 18:45
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I recommend Hobart MIG (assuming you want to use gas) welders for someone starting out, you can often find a used one for a good price. If you just want to learn fundamentals and don't need or plan to use shielding gas, you can pick up a new wirefeed unit for extremely cheap.
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Oct 11, 2020 19:08
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It might be harder to swing nowadays but i very strongly recommend taking a course or learning with someone else’s equipment before you go buying stuff; not only will you have a much easier time learning with a good-quality machine vs. an adequate starter machine and with instruction, but you’ll also work out what you really want from a welder in a way you can’t without relevant experience. When I was starting out with blacksmithing I bought a multi-process machine that did nothing particularly well and proceeded to almost never use it for anything until i sold it (but the oxyfuel rig i bought got a lot of mileage in the interim).
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Oct 11, 2020 19:26
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Sockser posted:Figure it's about time for me to learn how to weld (mig) ; what're some recommendations on good starting gear? We'll need some details on what you want to do. Sheet metal / body work, roll cage, fix farm equipment, etc. How thick will be most of the stuff you're trying to weld.
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Oct 11, 2020 23:26
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honda whisperer posted:We'll need some details on what you want to do. For what I see right now, mostly just welding square tube together for furniture applications, occasionally some 1/8” plate maybe
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Oct 11, 2020 23:57
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Sockser posted:For what I see right now, mostly just welding square tube together for furniture applications, occasionally some 1/8” plate maybe Any name brand in the 120-150 amp range will do. 1 amp per .001" material so 1/8" needs 125 amps as a rule of thumb. Then look at the duty cycle. The hobart 120 is 20% at 90 amps meaning 2 minutes of welding out of every 10 minutes. Less amps more uptime. 2 minutes is a lot of welding at a hobby level. Make sure you look at the duty cycle before you pull the trigger though. You can buy one without gas and upgrade later. I'd just go gas now if you can. Go to your local welding supply place. Whatever their brand is they'll have spares in stock. Being mid project and needing a widget you have to order sucks. Sorry we can't tell you what the current hot deal is atm. It's not a regular purchase kinda thing. I've got a lincoln tig and am borrowing a hobart mig. They're both awesome and old. I've used miller stuff too and it worked great.
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Oct 12, 2020 00:27
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Hello DIYers! We have a new forum/mod feedback thread and would love to hear your thoughts! https://forums.somethingawful.com/showthread.php?threadid=3944213 Get ready to read this message 15 more times in every thread you read! Kaiser Schnitzel fucked around with this message at 14:11 on Oct 16, 2020 |
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Oct 16, 2020 01:35
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Slung Blade posted:For a first pair of tongs, those are excellent. Well done and nice job. Thanks! In other news I bought a mig welder, been looking for a year until I came across an ideal model and brand. Bit tight in the shop for the forseeable future but a new building is on the way so I can move a lot of stuff out that doesn't need be in a heated environment.  The shop is a bit of a mess, the nut in my homemade wise gave up the ghost and those plasma cut plates are for a 2x72 grinder build. Well metric 50x2000 belts so more like 2x78. I really want one of those rolling magnetic things that pick up grinding dust, done a lot of angle grinder work in there, might have to stop doing that, not good for the machines, though I don't grind and then run them, and they got filters. But still  The tape indicates various dates from 2015 to 2019 and says SERVICE CLEANING. So I am imagening this machine was bought new around 2015 or before that, I am unsure when this model was discontinued and replaced with the Kempact series.  Came from a company that went out of business according to the seller, so he would have gotten it for an even better price since he sells at a profit and I paid a pretty good price I think (700€). Had 32A 3-phase plug so we could not test it since the norm in most garages here are 16A plugs (still plenty for this machine), he had not tested it himself. When I said I wanted to test it so we loaded it in my car and went to his friend a short distance away who had a workshop with 32A outlets and test welded it . It worked without problems, I even got a full 15kg spool of mig wire that was in the machine, think it is Lincoln wire.
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Oct 17, 2020 07:43
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Anyone used CO2 cores for sand casting? How well does it bust apart after casting?
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Oct 20, 2020 15:37
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