DIY Homemade DC Welder

Discussion in 'General Questions' started by ZnsaneRyder, Jan 22, 2009.

  1. ZnsaneRyder

    ZnsaneRyder Member

    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. :idea:

    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.
     

  2. ZnsaneRyder

    ZnsaneRyder Member

    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.
     
  3. skyl4rk

    skyl4rk Guest

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

    ZnsaneRyder Member

    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.
     
  5. brendonv

    brendonv Member

    :worthless:
     
  6. ZnsaneRyder

    ZnsaneRyder Member

    Hopefully soon my friend.
     
  7. ktjensen

    ktjensen New Member

    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
     
  8. ZnsaneRyder

    ZnsaneRyder Member

    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.
     
  9. seca40

    seca40 New Member

    "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.
     
    Last edited: Jan 23, 2009
  10. SirJakesus

    SirJakesus Guest

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

    SirJakesus Guest

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

    graucho Active Member

    Yes, interesting link. Looks very possible.
    Since having things go "BOOM" in the shop plenty of times the battery welder would kind of scare me.
    I think id have to have the battery configuration outside around the corner of the shop. Then have
    long enough leads so the acid impact wouldn't spray me.

    I do have the diagram's "series" etched into my mind though, if I ever had to get out of a jam. Thanks.
     
  13. Flapdoodle

    Flapdoodle Member

    MacGyver did it with a nickle and a 12 volt battery to weld a crack in an engine block. That was the last time I watched it.

    Seriously though, I suggest NOT wearing shorts as those two guys are doing on the link.
     
  14. srdavo

    srdavo Active Member

    I saw that episode ... it was a nickel! He's THE Man!! hahaha

    I'm trying to find the "old time" plans for a home-made stick welder. start with a pushmower...spinning an alternator... hooked to a 12v battery...lead & grd cables. sorta like this.... but smaller. http://www.mp3car.com/vbulletin/off-topic/68235-my-home-made-welder-few-questions.html

    here's another http://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/

    have y'all seen these mig welders? (store bought) http://www.readywelder.com/index.php
     
  15. ZnsaneRyder

    ZnsaneRyder Member

    The guy at mp3car can't get it to work right yet. He's paralleling them for high amps, and getting only 12V. The alternators are by themselves. If he ran them in series for 24V & used batteries with them, it would work. I honestly don't think alternators have enough power alone, but if they are recharging a couple batteries, they are VERY beneficial. I'm using a battery charger, to do that, and it does not have near the power of an alternator, but works great.

    Also the instructables about the microwave transformer welder was awesome! I gotta try that! I will be searching high and low now for broken microwaves! ROFL!
     
    Last edited: Jan 24, 2009
  16. ibdennyak

    ibdennyak Guest

     
  17. DetonatorTuning

    DetonatorTuning Active Member

    i have the full M.E.N collection from issue #1 on, to the time the they quit and were sold. none of the new back yard yuppy junk issues.

    i'll find the welder article and try to post it.

    steve
     
  18. skyl4rk

    skyl4rk Guest

    How long can you weld with a two battery system? Can you do a couple inches of weld before recharging? That would work out since a lot of times you have to stop and let the part cool off.
     
  19. ZnsaneRyder

    ZnsaneRyder Member

    A few inches works for sure. The voltage sags under load, but it comes right back up when you stop the arc. I had the battery charger connected to one of the batteries while it was welding, to replenish between the breaks, then I'd switch to the other battery and repeat. I may mod the charger for 24V of charging, so it feeds both at the same time.

    It really takes a while to drain down the car batteries. I didn't have to charge them for very long after I was done, I bet I didn't even drain them halfway.
     
  20. ZnsaneRyder

    ZnsaneRyder Member

    I'm sure we're all very interested. Hope you find it!
     
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