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Welding 101

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This topic contains 3 replies, has 3 voices, and was last updated by Avatar Ian 2 years, 1 month ago.

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  • #865169
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    Dave
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    I seen the struggle of someone welding and thought I would offer some advice. Now, I do not claim to be the very best welder, nor even close. There are much better people than me.
    The basics of mig welding flux or gas.
    1. Speed- If it is to slow, it will stutter or stop all together. (This will happen also if the surface is not ideal. Rust, paint, so on. If it is to fast, it will not lay down nice enough beads. Or even burn through the metal.
    2. Heat- If it is to hot, you will melt to much metal and start blowing holes. To cold and you will barely penetrate and booger up the welds. You want to see about 50% penetration between both of your seams. You want to watch the depth of penetration, and keep the other eye on the dimes you are laying down.

    Technique.
    1. Position- Hold the tip at a 45 degree angle about 1/2″ or so away from the actual surfaces.
    2. Direction- For beginners, it is easier to drag the weld from top to bottom, or left to right. You can see and control the shape of the weld better this way. Also it allows you to see much better the depth of penetration much better. Pushing the weld is much harder to see and control. It works great, but I prefer to pull the weld down or toward me. Easiest way I know.
    3. Hand position. Brace you hand on a surface or guide if possible. Wiggling and shaking hands just make for a horrible mess. With time you will steady your hands and lay down perfect beads with one hand with no assist. It takes a lot of practice.
    4. Beads- You want to let the wire form the dimes and slowly move forward as you go. Let the welder work the art. Pay attention to width, height, and penetration and hard the shape through the weld.

    Arc welding
    If you can mig weld, you got a great foundation for arc welding. Arc welding I think is the most consistent form of welding without going tig. It is smokey, stinky perhaps, however once you get use to it. You will weld like a champ pretty easy. Most of the same rules apply as with mig, however wire feed is not the factor. Most intense welding is done with arc welding. Pipe line construction and fence building. You can control depth, and bead a little more than wire. You have better results typically and a lot of stick sizes and types to choose from.
    Position- 45 degree. You are allowing the exterior of the stick to create the gap between the rod and surface. Lay the bead digging about 50% through the material and then back filling to your desired level. With mig or arc you can weld nearly flush pretty easy. Just depends on your application. Just depends on how long you take back filling the weld.
    Heat issues. Cracking in the seams. You are running to hot, turn it down. I have had to weld steel into cast iron. Super sensitive to cracking. Also iron reacts like a sponge when being welded. Keep in mind, if you are welding cast iron, go slow and cold. That metal will soak up the steel easy. Penetration is never an issue. If my product came out perfect but days later a crack formed, I would have to do it all over again.
    Thick metal to thin metal. Weld like you are welding thin metal. Lower heat and lower speeds. You will melt the thin stuff like it is wax.

    Disclaimer. I have welded for 6 years with no professional training. Stuck in a booth and told weld all this up. So there are much more informed welders out there than me, however having the basics, I do quite well for myself welding wise. At home, I have a cheap ole $100 welder that I can lay dimes with really easy. Just because it is cheap, it does not mean it is useless. Yes I rather have a nice tig welder, or even a gas shielded welder. Money is not here for it. Tig would be the bomb in my eyes. I have welded steel to cast iron, cast iron patching, cast iron reshaping (making artistic lettering and shapes for custom covers) I have welded Aluminum and I think I played with stainless as well. Love to have an aluminum welder as well. Stainless would be great. Moving from steel to Aluminum, totally less forgiving.
    Always practice, and get some practice pieces to play with. I have done artistic lettering into cast iron, artistic landscapes into iron, and reshaping intricate designs into iron. If you look at some decorative man hole covers, you will see some of the stuff I worked and possibly even my work from remaking bad spots in the molds. They tasked me with everything. Making and creating custom things for machinist, to custom jigs and all kinds of crazy stuff to modify things needed in the foundry.
    Anyway I hope this helps. Input is more than welcome.

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  • #865173
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    Rob
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    Aluminum welding I hear is hard to do…. I watch Eric on one of his videos trying to help a guy out and weld a camera stand the broke it was Aluminum and he really struggled welding it… I don’t remember if he was using a arc or tig welder… I posted him that to take a magnet and you can tell if its std steel or Aluminum…
    hey have you ever welded titanium before??? I hear a lot of ppl get shocked when they first work with it… it acts different then what they think it would… seen it you have any experience working with it and whats your thoughts about it

    #865179
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    Dave
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    Aluminum you need to keep cool. Welding certain metals does not work together to well. Iron and steel actually mix. Never tried welding titanium yet. As I said, you most likely need a special welder for it at the least. Copper and silver mix as well. Which is really common in electronics and in plumbing. Now if you use copper or brass against steel welding, steel will not penetrate it to well and really just the heat does a little bit. However you can actually shape steel welding with copper and brass plates.

    #887628
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    Ian
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    Saw this thread recently and thought I’d throw my $0.02 in. When I first left the Army and went back to school, before getting fed up with it and throwing my hat into the automotive world, it was in a non-destructive testing program. If you’ve ever had or bought a part that was magnafluxed or “sonic-tested” (It’s called UT or ultrasonic testing in the NDT world.) you’ve had experience with NDT. A lot of NDT involves welding, inspecting welds, that sort of thing. To that end, I spent a couple months in the afternoons goinng through a basic welding class and having a blast cutting up metal and burning up 7018 rod. Here’s the stuff that stuck…

    Basic welding methods- if you can imagine a way to stick two pieces of metal together, somebody’s already thunk it up. Lasers, explosives, thermite, you name it. If I remember right, there’s something like 100+ different welding methods. For the purposes of brevity, we’ll talk about SMAW, GMAW, FCAW, GTAW, oxy-acetylene, and resistance welding.

    Shielded Metal Arc Welding (SMAW)- Ah yes, good old stick welding. This is what I learned when I was going to school. Basically, you strike a welding electrode (A.K.A a stick) on piece of metal like a match and weld it up. If you want to learn welding, I HIGHLY RECOMMEND starting off with stick welding. You’ll lay down lots of gorilla snot welds. You’ll stick rods. But if you want to get into the other welding practices like GTAW or oxy-acet, you’ll have a leg up. The only consumable is the welding electrode and as long as you can get that sucker into a spot and strike an arc, you can weld it. Plus, the rods come in a variety of different flavors. Wanna seal up that pesky crack in a cast iron engine block? Heat it up nice and toasty with the torch and use a high-nickel rod. Need to make a field repair in the middle of nowhere? I’ve seen a video of a guy stick-welding off a deuce-and-a-half truck with a 24-volt electrical system using a pair or jumper cables and some vice grips as an elctrode holder. Seriously, learn stick welding…

    Gas Metal Arc Welding (GMAW) A.K.A Metal Inert Gas (MIG)- Apparently, this is the easiest welding practice to learn. What happens is a motor feeds a steel wire off a drum through a “gun.” Also being fed through the gun, outside the wire is an inert shielding gas. Pull the trigger on the gun, the wire and gas flows, you’re welding. Like I said, very easy to pick up, and very suitable to high-volume welding. Nothing against it, it has it’s time and place, but I feel that stick-welding is more versatile.

    Flux-Core Arc Welding (FCAW)- Similar to SMAW/MIG but instead of the the shielding gas being outside a solid wire, the wire’s tubular and with a flux inside of it which burns and forms a shielding gas. I dunno, I kinda like my shielding gas OUTSIDE the electrode…

    Gas Tungsten Arc Welding (GTAW) A.K.A Tungsten Inert Gas (TIG)- Now, this is the king of the hill. If you’ve the dough and the itch to make some really nice welds, especially on exotic materials like aluminum or stainless steel or you just like multi-tasking, this is the way to go. A sharpened tungsten (which has amazing high heat properties) bit held in a welding gun passes electricity to the work piece while being shielded on the outside by an inert gas like argon. While this is going on, the other hand feeds a filler rod into the weld. Some GTAW set-ups also have a foot-pedal to vary the voltage being fed to the tungsten tip. The process is pretty much smoke and splatter free and can produce amazing welds. In fact, douche bag and carbon steel though they may be, Jessee James TIG welds all his bike frames just for the aesthetic effect.

    Oxygen-acetylene welding- Part welding, part soldering. Essentially, you heat up the metal with an oxy-acet torch and feed a filler rod into the weld. Good for thin metal, but the torch is also good for other stuff we may discuss later. 😉

    Resistance welding- If oxy-acet is good for thin stuff, resistance welding is even better. If you’ve ever seen spot welds on the under-body seam of a uni-body car, you’ve seen resistance welding. Two copper jaws get clamped around a couple of pieces of thin metal. Something like 10 or 15 kilovolts (yes, kilovolts, with a thousand) gets passed the jaws. That amount of juice melts the base metal without the need for a filler and the parts get welded together.

    May add some more info later, but I think that’s enough for one night…

    TL; DR- have a vijeo- https://youtu.be/2fUAHkUfTps

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