Making an ARC Welder – Part 2 of 2

Making an ARC Welder – Part 2 of 2


In part 1 of this project, we scavenged some
parts from household appliances, and modified them so we could weld metal. In this project,
we’ll be rigging up the electrical system, and adding some finishing touches so that
our homemade stick welder is ready for operation. I started this project with a scrap piece
of 3/4″ plywood that I had left over from the “router table” project. And since we have
a router table, let’s profile the edges with a beading bit, just because we can. Next,
let’s cut a piece of 2×2, and screw it in from the bottom so that it’s secured in the
center, and about 1″ from the edge. We’ll also need to drill a couple of pilot holes
in the top, because this is where we’ll be attaching some copper lugs. To make these,
we simply take a piece of 1/2″ copper tubing, and use a hacksaw to cut 2″ from the end.
Half of the tube can be placed in the jaws of a bench vise, and when the vise is closed
with a significant amount of force, you can see that we’re left with a nice flat end.
Let’s place that on another piece of scrap wood, and drill a 5/32″ hole so that it penetrates
through to the other side. I’ve done this with 4 different pieces, and to clean up the
rough metal barbs, I’m using a belt sander to gently file away at the edges until it
looks a little more user friendly. This lug here is gonna attach to a 5′ length of
8 gauge cable. This was left over from when we wound our coils. We’ll just need to strip
about 2 inches of insulation from the ends to expose the copper wire, then bend the wire
over with a pair of pliers to form a little loop. The exposed copper loop can be slid
inside the casing, and to make this a permanent connection, let’s crimp it onto the cable
using the bench vise like we did before. This connection isn’t coming apart, and should
easily handle the high currents that we’ll be exposing it to. The other end of this cable
will be our ground clamp. I got this metal clamp for $0.99 and with the rubber tips removed,
it’ll conduct electricity. I crimped a pice of copper tube to the end of the wire, and
secured it to the clamp with a screw. The spring in the clamp is surprisingly powerful.
It bites down with a good amount of pressure, and that’s what we need for making a firm
connection with our workpiece. Now a welding rod could just be pinched to the cable with
a pair of pliers, but i went ahead and spent $13 on a proper electrode holder. This makes
it look more like a real welder, and adds a tremendous amount of convenience and control.
Ok, we’ve got our lugs crimped on the ends of the secondary coils, so let’s mount the
transformers on the base. You probably noticed that I cut the cable in the middle, and crimped
them to a common lug in the center. This is because I wanted an option to center tap the
transformers to power other devices, like an electrical arc furnace. Look for how to
make that in a different project. A few screws can be used to hold the transformers in place,
and the grounding clip can be connected by overlapping the respective lugs and pinning
them down with a screw. The electrode holder gets attached in the same way, and here you
can see there is plenty of separation to prevent the terminals from shorting out. Alright,
let’s get ready to rig up the electrical system. This cord was saved from one of the microwaves
we tore apart, and after exposing the 3 wires inside, I’m gonna cut off the green one
just to get it out of the way. It’s not gonna to be connected to anything. Now here is the
trick to powering the welder. 240 volts AC. I can’t recommend this is the safest way to
do it, but here’s how I did it with a couple of plugs, a connector, and some 10 gauge wire.
Each outlet in my house provides around 120 volts AC and they’re connected to a circuit
breaker bus bar. There are 2 breaker busses, and if a hot lead is taken from each of the
busses, we get 240 volts. Now rather than tapping into the breaker box directly, I ran extension
cords to 2 different wall outlets that were 180º out of phase. The extension cords connect
to this adaptor, which basically just connects the 2 hot leads together. If connected properly,
the end result is 240 volts. Looking at the back of the transformers, you can see 4 terminals
that connect to the primary coils. I used some salvaged cables and wire nuts to connect
a hot lead to one transformer, and a hot lead to the other. Another wire was used to bridge
the two, connecting them in series. By the way, the color of these wires doesn’t mean
anything. They’re all gonna be shock hazards. Ok, to finish up, let’s fasten the power cable
to the base so it doesn’t pull the connections apart if the cable gets jerked around. It’s
extremely important to remember this system has no on or off switch, and can only be used
with a power controller, like the Scariac. You can see how to build this in another video.
If you remember back to when we inserted our new secondary coils, I mentioned it didn’t
really matter which way they went in, and here’s why. When the power is on, and our
welding electrodes are connected to a multimeter, we should expect to see around 36 volts. But
here we’re only getting 2.4. That means the transformers are canceling each other out.
To fix this problem, let’s just turn off the power, and remove the connections to one of
the transformers. It shouldn’t really matter which one. Then we simply, switch the connections
around. That’s it. This time when we turn on the power and check the voltage, we’ve
got 37 volts. Now, rather than leaving all the dangerous components exposed, I think
we can build a make-shift casing from this plastic container. Here are the exact measurements
if you care to know. I choose to use the lid as the base, and used a rotary tool with a
cutting wheel to make the surface flat. Our entire welding assembly should fit right in
the center without any problems. I gave the whole container a paint job, set the bin into
position, and locked it into place. Two holes went in the front for our electrode cables,
and I also cut some ventilation holes on the sides. There’s a hole in the back for the
power cable, and now our welder is completely finished and ready to test! Let’s start by
directly shorting out the ground clip with the electrode holder, because this will allow
the maximum amount of current to flow. We’ll use an amp meter to monitor the primary current,
turn on the Scariac, and power up. When the power settles at around 15.5 amps on the primary,
you can see it produces about 100 amps on the secondary. The amperage is adjustable,
so if we add more power, we can jump the welding cables to over 200 amps. In any case, there’s
certainly enough power available to strike an arc, sustain it, and weld some metal. You
can see some of my first few experiences, with the world of welding, in another video.
Well that’s it for now. If you liked this project, perhaps you’ll like some of my others.
Check them out at www.thekingofrandom.com

100 thoughts on “Making an ARC Welder – Part 2 of 2

  1. I've built this Arch/stick welder, and his spot welder and the scaryach. All work well !!! Except the spot welder instead of 3 wraps I should have wrapped 3 times around the transformer . Thanks Grant !

  2. If you split between two 120v's, you cancel the ground. A very quick death. Spend a little more to have a 240 outlet installed.

  3. I'm wondering if its possible to run 3 transformers in series where you could use 1/8 inch electrodes because they are a lot cheaper?

  4. So this guy has already spent at least $30 in parts and who knows how many hours making this death trap, you know you can buy a fully built and tested arc welder from Harbor Freight for around $60 when it on sale, which is quite often

  5. Do you think you could use a tungsten tip instead of a stick in order to make more precise welding ??
    If anybody has a comment about that, it will be very much appreciated
    Regards

  6. Each outlet in my home provides 110 Volts AC. Should it work on 220 volts or do I need to power it on 330? If 330, then is there a setup of your choice to power the welder?

  7. never wear loose fitting gloves around moving machinery including drills! it can do alot of damage in a blink of an eye and when it pulls u in you cannot pull away!

  8. At (314) you say that you have left "plenty of separation" between the terminal lugs but if that single screw works loose the lugs could very easily swivel and short out.
    Even if the screw is tight, I'm sure a sharp tug or yank on the wire could do the same.

  9. Hey, i wish to make the same.. I've some questions.. What if i dont have a scariac or dimmer.. Can i directly power it through 230v

  10. man you could simply connect the primary windings in parellel to use it on 120v ac. But oviously it would work bether on 240v

  11. The King of Random: I tested the portion of your video about "220/240VAC". I've never been able to get a phase voltage of 220/240VAC. And I think I understand the reason: it must be a matter of local regulations regarding how to dispose the circuit breakers.

    At your home, I think I saw only 120VAC circuit breakers on both sides of
    your electrical panel while here, where I am, the left side of my
    electrical panel are installed 120VAC circuit breakers and, on the right
    side, those 220/240VAC.

    What made it so that having the same 120Vac busbar, my multimeter indicated 0Vac.

    Therefore, people who want to build a welding station like yours should check
    before the layout of the circuit breakers in the electrical panel of
    their house.

  12. Find the smile 😃 if you do find it like it and reply

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  13. My arc works on a normal 120v outlet but as soon as I connect it with 240v with the way shown in the video it shorts out. Does anyone have any idea as to what the problem is?

  14. I have many HPS or HID ballasts. Does it make a difference when it comes to rewire the transformer or it will only make a difference with the primary tension? And consequentely a bigger voltage/amperage on the secondary?

  15. For the miny arc furnace, I would use the outlet behind the Electric Stove or Washers. They are 240 volts and the‎ plug can be bought at Home Depot for cheap. This way you don't have to run a cord thru out your house.

  16. You explain things very well like school teacher.

    I would like to know how you can improved your system, so it can weld different amp.

    Do you have time to make another video for that?

  17. Instead of 240vac, the same can be done with 120vac, but you will still need two outlets (each on different circuit breakers), on the same buss. In some cases, one might have two outlets relatively close that are on the same 120vac bus but go to two different circuit breakers.

    In the video, he wired 2 transformer primaries in series and connected to two outlets each connected to a circuit breaker, each on a separate 120vac buss. The the Y plug connects the hot to one end of primary coil with the other side of the Y plug hot connecting the that circuit's hot to the one end of the other primary coil. Neither neutral or ground were mentioned. Then the two primary coils other leads are connected together with the end result of having two 120 volts coils connected in series. Lack of grounding in this is very scary.

    The way to do this with two outlets on different circuit breakers on the same 120v buss is to forget the Y adapter plug and just run an extension cord from each outlet to each transformer. Things should be the same on the secondary coil.

  18. What is the minimum wattage capability that you would recommend for the variac to be used with the welder? I would prefer to use a commercialy available variac, and would prefer not to use something that would be overpowered.

  19. That s pretty awesome . if anyone else's dose this same project I don't recommend puting her on full pulls off 200amps .

  20. I don't understand why you had to use 220v to power the primary coils in series. Couldn't you have used a single 120v phase to power the two primary coils in parallel but connect the secondaries in series. You would just have to get the polarity of the secondary terminals right and you will get twice the voltage of a single secondary winding, so your end result will be the same but in a safer way.

  21. 5:23 120v rated what about 240v rated transformer should i connect mains in parallel or series and how much current and watts it consume

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