• Automotive and Motorcycle: [WON RUNNER UP!]

I was interested in a "portable welder".  I started investigating and I found a few gas and propane driven models from $699+

I then found a great Instructable that started me thinking in a different way: https://www.instructables.com/id/SpoolGun/

Instead of a gas generator powered welder, I could use a 24V DC battery powered welder system; based around a spool gun.

I currently own a Lincoln 175HD 208V [220V AC circuit] welder which can weld aluminum via its push-wire gun, but it requires changing out a liner in the gun's cable so that the wire doesn't "birds nest" [bunch up] in the feed tube.  Needless to say, it raises the threshold of "what's worth the trouble" of switching everything out.  Lincoln now makes a separate spool gun that works with the newer models of Lincoln welders, but not with my 175HD.  I found a great "retrofit" website on how to wire the spool gun for use with my welder.  Having a spoolgun that I would use for aluminum welding, and the push-wire gun for other wire types, would lower that threshold, and I could also use the spoolgun for my portable welder idea.

So while Tim Anderson's great Instructable is based around a generic spoolgun that he found on ebay [priced in the $135-$150 range], I decided to go with the Lincoln Electric Magnum 100SG Spoolgun [priced in the ~$222 range] so that I could use it with both my existing AC powered welder and the DC welder that I had in mind.

Complexity:  Intermediate, requires:
  • knowledge of welding
  • knowledge of DC electronic circuitry
  • experience with High Amperage vehicle batteries

Safety: *Special precautions*
  • I am not a professional certified welder nor electrician, so understand that you (like I did) assume all responsibility and liability for attempting to [re]create this project.
  • Not going to get into the whole Edison vs. Tesla debate of the safety of DC vs AC, but for this specific project, DC is relatively safe.  Relatively in that you won't get "shocked", but the arc from high amperage DC current releases various gasses, radiation, and produces enough heat to seriously burn, even maime.
  • While welding, make sure you use protective gear and cover your skin.  A DC arc can generates molten metal slatter, enough ultraviolet radiation to give you a sunburn, and can permanently damage your retina if viewed with the naked eye.  Be cautious of any spectators/bystanders

Step 1: Parts List

Lincoln Magnus SG100 Spoolgun $222.00
Stanley FMST20261 FatMax Metal and Plastic Toolbox with Drawer [Limited Quantity Remaining] $51.45
50' of 1/0 Welding Cable [25'red/25'black] $130.00
Positive & negative set battery ring insulated junction post terminal block stud $15.00
NEW waterproof DC/DC Converter Regulator 12V Step UP to 24V 72W 3A $24.99
NEW waterproof DC/DC Converter Regulator 24V Step down to 12V 120W 10A $19.99
Bussman DC Circuit Breaker 150 Amp Surface 181150F Auto $31.99
[20 total] Solder Pellet Solder Slug for 1 Awg wire Pink $13.00
[8 total] Solder Pellet Solder Slug for 1/0 Awg wire Black $6.80
[4 total] Anderson SB175 Connector Kit 1/0 Awg ~$28.00
[2 total] Anderson Power Poles connectors PP120 $2.35
12V 40A SPST Premium Relay & Socket 4Pin 4P 4 Wire For Car Auto $4.99
S18884 HOSE NIPPLE $4.65
T9078-3 THUMB SCREW $1.35
20A-350A Contactor $98.00
Circular Connectors - Contacts > SA3349/1 $12.95
NOT CHEAP, but was exactly what I wanted!      Total ~$750.00

      * These come in a selection of colors which are interchangeable EXECEPT for the yellow ones. The yellows plugs only fit other yellow plugs
      * I was unable to find the specific connectors that fit the PP120s. I was able to grind down two of the connectors from the SB175s to fit, but it would probably be best to just buy another set of two of the SB175 connectors (for a total of 6).

Excellent useful info, thank for sharing!
Thank you very much! This was one of the few projects that moved from experiment to project on the first try! Plugged it in, pulled the trigger and it welded! :)
<p>Would love to see a video of it welding.</p>
<p>or further, eliminate both transformers and use a 24 volt contactor &amp; 24 volt relay? Is the trigger switch only rated for 12 volts? </p>
<p>Hi, Nice set up. Studying the schematic, I'm curious if you could reduce the overall cost of this by using a golf cart solenoid, like this: <a href="http://www.ebay.com/itm/SOLENOID-RELAY-BATTERY-ISOLATION-SWITCH-12V-300-AMP-/131841709295?hash=item1eb260d4ef:g:Z90AAOSwVFlT4lV~&vxp=mtr" rel="nofollow">http://www.ebay.com/itm/SOLENOID-RELAY-BATTERY-ISO...</a></p><p>in lieu of the specified contactor? Also, is it possible to eliminate the step up transformer altogether by feeding the motor relay from the primary side of the step down transformer, and use the stepped down 12 volts to the trigger only to actuate the relay &amp; solenoid (your contactor)?</p>
<p>nice collection</p>
You've had this set up for a good bit of time now. Have you made any interesting mods to the original design? I'd be very interested to hear
can we see this running ? like a video or something. Im a student in a welding class and my teachers are pretty interested by your way of making a portable welding machine
I'll see what I can do this weekend.
Any estimate on run time with a fresh or fully charged pair of batteries?
I went through 1/2 lb of wire with no discernible drain on the battery. I wired them back in parallel and started the engine right away. I use a series of solar panels (just 45watta) to keep the batteries topped up. Haven't had a need to weld any longer in one go. <br> <br>
Very cool, thanks for the reply and fantastic instructable.
Wow! Well done! You have a great skill set to DIY this!
Thanks! I'm a computer programmer (started in computer engineering, so have some basic electronics knowledge), and my father is a retired machinist and welder. He taught me the basics. <br><br>I consider myself a Zac-of-all-trades, so pretty fearless about trying new things. Only had one all-out DIY failure (water cooling a computer of all things, but I tried for WAY too much for my first such project).<br><br>I've got a few Instructables planned for the year. I reworked and updated an older Instructable: Survival Kit Shotgun, I just have to get it recorded.<br><br>I'm also going to start some extensive mod'ing of my hummer H2, and a possible HUD for my motorcycle helmet now that transparent OLEDs are coming down in price.

About This Instructable




Bio: At 48, I have a vast array of experiences that cover many interests and technical domains. I started programming at 16, 1984, on an Atari ... More »
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