Spool Gun Handheld Wirefeed Welder Powered by Car Batteries

Here's my new wire-feed (MIG) welder.
All of it.
They sell these things as accessories for commercial MIG units, but they can also work great on 24 volts from two car batteries.
I have it loaded with .030" flux-core welding wire.
It cost me less than $100 on ebay.
The "Ready Welder" is a similar commercial product.
WARNING: The tip is electrically on all the time!

Cheap Welding for Punks compares this gizmo to other homebrew welding methods.

In the following video, notice that I'm controlling power with the distance to the work. Close in melts in more, further away increases the wire resistance. That decreases current and the weld is cooler and builds up metal in a taller puddle. Notice that my first weld is terrible because I forgot to do that. The next two welds get a lot better. These are two random batteries that have been sitting out in the yard for at least a month. I don't know how well charged they are.

Thanks to Star for videography and other good works.

Want more homebrew welders?
Try an AC stick welder from microwave oven transformers,
DC stick welding with car batteries,
Solar powered golf cart welder

Step 1: Gun Shopping

Spoolguns are sold as accessories for MIG welders for welding aluminum. The aluminum wire tends to jam up in a conventional wirefeed welder. So people get these spoolguns. They also get them for confined spaces and to work longer distances from the powersupply unit.

I bought this spoolgun on Ebay for under $100. There's no brand name on it and no provision for shielding gas. It's well made and works great for flux-core wire. I don't see any like it at the moment, but there are a number of Miller and other major brand spoolguns for sale. Do "show completed listings" to see how much they've been going for.

Comments

[HiramAbiff]

I think I saw a post here about using a couple of microwave power supplies. My question is, could this be done with a couple of pc power supplies (I imagine in series to get the voltage up closer to 24 volts -ish)? As these are switching supplies, I am nit sure this would work out. If it did, I am thinking that the 40 +/- amps one could get from a pc ps (or two in series) would be plenty for aluminum. Of course, since there are a lot of these things around for almost free at surplus, maybe use 4, a set in series and each set in parallel to up the current if needed. Am I on the right track, or would the switching ps or any other aspect of a pc ps make this a bad selection for a spool welder ps?
Thanks in advance.

Dan

[Adam Manick]

In theory it would work. I was planning on building something very similar to that (I'll post an Intractable if I do). The problem is that flux cored and mig welding both work best on DC; the microwave transformers obviously have an AC output. Now, some cheaper flux core units do use AC, but this produces welds with allot of spatter. The only way to do it properly would be to rectify the output, and the diodes can get pricy. Another obstacle, is that mig welders do have to be adjusted more so than others; a stick welder for example. So, it would be best to also have a way to adjust the current.

[L3indy1965]

Might you describe the wire hook up, can't make it out from the picture?

[jj.inc]

I don't get why people think that all these currents are so different. Our school shop has Lincoln stick welders that run DC with the work clamp positive or negative, and they have AC. I guess for this kind of welder a positive tip is different but not for "all" of them.
By the way, great video.

[everywhere]

does your school shop have mig welders? if so then you should know that polarity maters using flux core(DCEP) versus solid wire(DCEN). that don't mater much on arc welders the polarity on those is dependent on where you want the heat to go(though if your welds have the DC ability don't use AC).

[frontpage]

hi there ok question how hard wold it be to make the battery power variable so rather than having to vary distance you just vary vary the voltage something like a foot pedal for a sewing machine but beefier ? would this work and how hard to do ? or some sort of dial ? ? ? ? sorry far from expert hoping this adds to this and so want to try this .. alot cheaper than $500 for a bigger used 120v mig welder too lol ..

[jchambers]

you could just buy a cheap mig on ebay, and feed it with fluxcore rather than buying a gas canister.

[onlyeh]

Nice mobile get you out of trouble idea. You can do the same with a set of jumper leads and some welding rods.
Beware that it is a dangerous practice as the batteries give of a very flammable gas when worked hard and the sparks canmake them explode spraying you and everything with Acid and not to mention the fire burns, so good ventilation is needed and some cover on them to keep sparks away.

[pseudoki]

very nice instructable, any chance you could weld aluminum with this setup?

[abadfart]

very cool I'm going to make a transformer to output 24 v  so i have a small rig to keep in my apartment

[twenglish1]

where can i find one of those spool guns, fairly cheap, and could i hook the spool gun up to a stick welder? will it work like that?

[ravingking]

i was thinking exactly the same . my welder is 48v 200a and i reckon thats to much. any help would be great

[twenglish1]

mig welding is done around 20 - 30 volts right? and the use a constant voltage power supply, instead of the constant current stick welders use, the voltage on my stick welder is too high anyway, i measured it, it is like 80 volts open circuit voltage that is

[MrRodrigez]

sweet i think i might try this for practice in welding class

[vernors]

can u use 2 microwave transformers (with 10-guage wires for the secondary coil) instead of 2 car batteries.

[bylerfamily]

Yes.

[dodgedartgt]

Tim, I enjoyed reading through your welding tutorials, thnx. This one in particular has intrigued me. As for the tip always being "hot", I think there is an easy way to resolve that issue. At the junkyard, grab a starter relay (I think the Ford style double post would be ideal) and use the roller feed power to energize the tip when the trigger is pulled. Just an idea I thought I'd share. Mike Bynum

[John Kiniston]

This is really cool.

[Lor]

love the hat!

[Sandisk1duo]

i wouldn't park my car on those ramps...

[cowgomoo]

yah the welds didnt look very nice... but who knows... im not very experienced in welding.

[cowgomoo]

oh its cuz its chicago brand haha

[Lor]

I think they look great. And if you're concerned about cosmetics, you could always put a finish on them. This project is great. I've been looking for this. I'm not a welder, and I don't want to spend a lot of money on the equipment when I'm not going to do it all the time. But I need it for a project. Thanks so much. You've saved me!

[Derin]

Quoting TimAnderson:

A wise lady once told me:"A project isn't finished until there's a finish on it.Get it?"

[Lor]

very punny!

[mikemmcmeans]

the bamboo is amazing apply this to a soldering iron, using the small tubes of solder stead of a spool

[lukeyj15]

what about using thick solder instead of flux

[mikemmcmeans]

nevermind, i have dibs on this instructable

[Spokehedz]

They make those already, and they absolutely STINK ON ICE. The problem is that unlike welding, soldering requires the wicking process to actually get into the joints of the part/wire. Welding is just blobbing new material to melt the other two metals together. Plus, you don't want to constantly be feeding solder into a joint. You want to heat the joint (touch the iron to the part) and then touch the solder to the other side of the joint (NOT THE IRON) and let it flow into the joint.

[Derin]

So that was why my solder joints were terrible...I was touching them to the iron to melt it. I am a bit lazy. :)

[ear0wax]

That actually harder to do than soldering properly. Dont worry ever one does that at first.

[Spokehedz]

Well, I think that it's how most people who teach people how to solder... They teach cleaning the iron first--which is blobbing a bunch of solder onto the end, and wiping it off on a sponge... and that sticks in your head on how soldering works. I blob the solder onto the iron, and then it sticks to the part. This is flawed for a couple of reasons. 1) The solder never sticks, as the part is COLD and the solder is HOT. 2) The joint that is made is always a 'cold' joint because the flux boiled off on the tip. 3) People love watching solder melt for some reason--and this gets them thinking that you need a LOT of solder when you actually need very little. What I do, I teach people how to tin wires first--a skill that I see as being the most important one in Soldering. How I do this is I clamp the wire into a handy-holder and then tell them this: 1) heat up the wire for a second. 2) touch the solder to the wire, and watch it wick. 3) move the iron up and off the end of the wire. Taa-daah! And then i move onto though-hole components. Same principal, only with a component leg rather than a wire. The students pick up instantly on what they should do. Then I move onto SMD which is only marginally trickier. Replace "wire" with "component" and the steps are the same. Once that is all out of the way, then we learn cleaning. Wipe it off on the sponge/stick it into the copper cleaner. There. Now they have all the skills they need for soldering, and IMO in the proper order of importance. Sure, a clean iron is a happy iron--but if you don't constantly blob a bunch of solder on there, and let the flux burn off, then your iron wont get dirty in the first place. Proactive thinking, rather than Reactive thinking.

[snowluck2345]

I always leave a blob of solder on my soldering iron and I use that when soldering, but just to get better heat conduction between the iron and wires. Then I apply solder to the wire.

[cberes]

How long of a bead were you able to put down before the batteries gave out? How often did you have to recharge your batteries?

[mschefter]

Cool Instructable! I will diffidently have to make something like this. Would be perfect for quick and dirty fixes on the off road trail!

[wibrle]

Very cool project. Just add solar panels to the batteries, and the welder's power will be green and free. This is a project I will have to try. Thanks for sharing :)

[LinuxH4x0r]

Not bad! I personally prefer stick (SMAW)

[The Lightning Stalker]

     Yeah, stick is better for thicker pieces and where you can't get away from drafts. For thinner stuff like sheet metal though, I find that stick is much hotter and tends to burn through. It's much easier to use oxyfuel or wire. The wire comes in diameters all the way down to .024" so you can turn the heat way down. Sticking and hard starts aren't even an issue since it uses a short circuit to melt the wire instead of an actual arc. As long as the feed speed is set right for the wire and voltage you're at there won't be a problem. Cheers.

[LinuxH4x0r]

Yeah, it has its advantages. But if you get an oxy-acetylene setup you can put on a 00 and cut or switch on a 5 to weld and you can do anything. That and a nice smaw would be my ideal setup.

[Derin]

i prefer the simplest stick welding (AC with no controls)