Help with onboard battery arc welder

[Freeride]

Leads
20 feet, 4 gauge welding cable, 200 amp ground clamp and electrode holder, crimped on battery lugs.

Batteries
2 Exide Orbital Marine Deep Cycle (http://www.exideworld.com/products/m...eep_cycle.html )

Circuit
DCEN. Batteries connected in series by short red jumper shown below. Approx 4†long, 2 gauge.

Rod
1/8†6013

Previous Welding Experience
6 years AC stick welding, 1 year TIG steel and aluminum, 1 year MIG.

When everything is connected, I measure 25 volts at the stinger and ground clamp. Right away I find it VERY hard to strike an arc. Much harder than with my old Lincoln AC machine. I’ve never welded DC before, so I don’t know if this is inherent with DC welding, or unique to my setup. Literally, I spend 30-60 seconds just trying to strike the first arc. Once I strike an arc, it’s VERY hard to maintain. It arcs with power, but fizzles within a second or two. I haven’t been able to keep an arc going for more than probably 3 seconds. On my big AC machine I have no trouble running a continuous arc bead for the entire length of the electrode. The welds below were all done with 1/8†6013 DCEN. I tried 6011 and found it impossible to get any kind of bead going. I also tried DCEP with both electrodes and that worked terribly. The only setup that worked at all was 6013 DCEN.

Do you guys have any comments on my setup? Does everything look right? Do I just need practice? I’m to pick up some 3/32†electrodes and see if those make any difference. Beyond that I don’t know what I could change. The welding cables never get warm like I would expect if the wire was too small or the leads were too long. Even after messing around with trying to weld for close to an hour, the batteries are just a hair below 25 volts, so I have plenty of reserve power.

I can barely get this setup to weld under perfect conditions in the garage. I need it to be user-friendly enough to be able to use it lying upside down in the snow/mud in a downpour.

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[crash2]

Thats odd. With that rod you should have no problem. Now granted the voltage source not being constant and be kinda tricky but it should work.
I have only welded like that a couple of times and that was in the snow/mud with not so good rod. Now granted we also used 3 batteries. I know with my setup 2 batteries and I burn steel like no other...

 

[Freeride]

Thats odd. With that rod you should have no problem. Now granted the voltage source not being constant and be kinda tricky but it should work.
I have only welded like that a couple of times and that was in the snow/mud with not so good rod. Now granted we also used 3 batteries. I know with my setup 2 batteries and I burn steel like no other...

I think I'm going to have to break down and buy a ready welder! I'll give it a shot tonight with 3/32" 6013.

 

[crash2]

I love mine--works awsome!!!!!

 

[Freeride]

I love mine--works awsome!!!!!

Where'd you buy yours? I see them on ebay for just under $400. 6 months ago there was one on craigslist for $200, but I didn't have the cash at the time.

 

[crash2]

Where'd you buy yours? I see them on ebay for just under $400. 6 months ago there was one on craigslist for $200, but I didn't have the cash at the time.

I went thru my MAc tool guy and he got me a pretty decent deal. But $400 seems to be the going price now..

 

[Not Jobless]

My 2 cents...

Looking at the welds John it looks like either your rod is contaminated or the joint is.

20' feet worth of cable may be a little long...every inch will add resistance and drop power.

The other thing to try is twist your two cables together like you would do for DC or AC power cables in a piece of computer equipment. It will cut back on the unequal magnetic field being created by the seperation of the source & it's return. I've seen this cause arc problems before with DC welding at school.

 

[Freeride]

My 2 cents...

Looking at the welds John it looks like either your rod is contaminated or the joint is.

20' feet worth of cable may be a little long...every inch will add resistance and drop power.

The other thing to try is twist your two cables together like you would do for DC or AC power cables in a piece of computer equipment. It will cut back on the unequal magnetic field being created by the seperation of the source & it's return. I've seen this cause arc problems before with DC welding at school.

The rod was brand new and the steel was reasonably clean. I think all the voids & inclusions are from the starting and stopping. I could never maintain an arc for more than a few seconds or a few weld ripples. In the very last picture the bead is maybe a foot long and I started/stopped probably a dozen times. I'll try cleaning a little more and see what happens.

The way my batteries are mounted, it would be a PITA to remove them, so I was hoping I could make 20' leads work. That way I could reach any corner on the Jeep, or drive up to a dead rig and reach any point on it.

I'll try twisting the leads tonight too.

Thanks.

 

[SkicoFab]

i don't see any problem with your power source. and you are welding with 6013, which has furious digging characteristics and it's design is actually to be used in dirty, rusty, or even painted weldments. i would understand if it was dirty and you couldn't get 7018 to run worth a crap. it might be that 25 volts is just not enough to get that arc going. our smaw machines have an open circuit voltage of 80, so that helps a ton when striking the arc, then it steps down when you stabilize the bead. thats my best guess is just not even volts to get your burn on and start the bead. have you tried striking an arc and then increasing your arc gap, and see how long you can run it like that? because when running low voltage like that it's very hard to maintain an arc especially when you're holding a tight arc gap. i can understand that you're having the best results with dcen, but ideally you want to run dcep. with dcen you aren't getting the penetration you want, because the circuit runs from positive to negative, so in a dcen it would be running from your workpiece to your electrode, but it is harder to run dcep with lower power because the current is running from your electrode to your workpiece resulting in better penetration, but harder to strike an arc when not running your ideal voltage. well hope something i said was useful.