DIY Homemade DC Welder

[ZnsaneRyder]

I just built a simple, but powerful welder and it works great! I've been really needing to get someone to weld a 48T sprocket to a hub for my bro's trailer, but got tired of waiting on people, so I decided to do it myself.

A typical MIG or rod welder is 24V and 90-170 Amps in most cases, and just uses a short circuit to melt the metal. I based my DIY welder from this knowledge, and did it my own way.

- The DIY welder consists of Two 12V car batteries. Both batteries rated at 630A/525CCA.
- Also 6 AWG wire to connect the 2 batteries in series to get 24V.
- Heavy-Duty 6AWG jumper cables with good clips
- 2/10/60A 12V battery charger to feed the batteries.
- 14AWG solid copper household electrical wire to use as welding rod

With some trial and error, I got it working right! Negative clip on the steel sprocket, positive clip on the welding "rod". I did not have any regular welding rod, so I first tried 10 gauge galvanized steel wire, but it just glowed bright yellow and caught fire. My brother mentioned the copper wire that I had plenty of, so we gave that a try, and IT WORKED! The copper doesn't glow when you have a good arc, except on the end of the wire. I noticed that you have to start on bare steel to get it going, then move quickly as the copper wire melts. The copper bonds to the steel very well, and makes a bright blue arc. The wire melts FAST because there is over 500 AMPS of power, which is more power than a regular welder.

The battery charger was alternated between the two batteries during breaks to keep them charged.

The welds aren't pretty, but they melted easy and hold VERY well, and plenty of material was used to make a strong weld.

I had to use several pairs of sunglasses over each other and take breaks between spot welds, as it was very bright, but not quite as bright as steel wire on a MIG welder. A bright blue arc is what it produces. I'm going to get a cheap welding mask soon to do more and better welds.

This new welder opens up so many possibilities for needing large crude welds, and now can complete many more tasks! There is plenty of power, so the welds bond instantly without heating up the surrounding metal too much. I'm rather pleased.

 

[ZnsaneRyder]

Also forgot to mention.... You have to use two batteries (24V) to overcome the resistance in the wires, and to get a "pop" to start the arc. A single 12V battery would just glow the metal mostly without welding it much.

Now I see why regular welders use 24V or more.

 

[skyl4rk]

Set the batteries behind something so if they blow up you don't get any acid on you.

 

[ZnsaneRyder]

Set the batteries behind something so if they blow up you don't get any acid on you.

Thanks for the tip. I'll be careful as I always do.

I constantly monitored the voltage of the batteries with a multimeter, and didn't keep the connection going for more than a few seconds at a time, to prevent battery damage and over-discharge.

 

[brendonv]

 

[ZnsaneRyder]

Hopefully soon my friend.

 

[ktjensen]

I the world of ROCK CRAWLING (driving jeeps over steep impossible paths) there are many who do this with batteries. When you are out in the field it is impossible to bring a welder. So you make your own with two or three batteries.

You might want to do some google searching and reading about this and how to optimize the procedures safely.

http://www.lcool.org/technical/80_series/bat_weld/battery_welding.html

 

[ZnsaneRyder]

That's a good article ktjensen! Thanks, I didn't know that people have done this before!!!

They mentioned using THREE batteries, but it seemed that two batteries welded their vehicle trailer's leaf spring just fine. I am using thicker wire than they are and no "resistor" wire to limit the current, so I had NO issues getting an arc at 24V.

 

[seca40]

"I had to use several pairs of sunglasses over each other and take breaks between spot welds, as it was very bright, but not quite as bright as steel wire on a MIG welder. A bright blue arc is what it produces. I'm going to get a cheap welding mask soon to do more and better welds."

Hahahahaha. That's too much man. I almost spit cofee when I read this. That's awesome man where there's a will huh? Be careful. Post pics.

Oh, man I just remembered. There was a McGuyver episode where he did this. He used a silver dollar for a "Rod" though.

 

[SirJakesus]

This is really cool. Thanks for the thread. I'll have to try it sometime just to make my family sh*t bricks.