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View Full Version : Ground-clamp idea, good or bad?



Banshee
08-18-2011, 09:56 AM
I have a Hobart Handler 140 MIG with gas. I find that the Cheapo "jumper-cables" type grounding clamp it comes with often will not stay on med-large diameter tubes, so, I was thinking of get a pair of c-clamp style vice-grips(like in the pic) and drill a small hole(where the red dot is) and anchoring my ground wire to them...

Would this be a bad idea for any reason I am unforseen...?

Any input greatly appreciated!

Trike Lover
08-18-2011, 10:41 AM
I have a Hobart Handler 140 MIG with gas. I find that the Cheapo "jumper-cables" type grounding clamp it comes with often will not stay on med-large diameter tubes, so, I was thinking of get a pair of c-clamp style vice-grips(like in the pic) and drill a small hole(where the red dot is) and anchoring my ground wire to them...

Would this be a bad idea for any reason I am unforseen...?

Any input greatly appreciated!

The material of the clamp is not necessarily going to be low resistance, depending on the metal used. This may result in the clamp getting very warm. Also, the actual contact surfaces will become pitted.

Perhaps consider running the ground leg cable to a removable electrode cap that fits over one leg of the clamp pincer faces. A chunk of copper strap and a couple of nuts/bolts, plus a couple of small holes drilled through the clamp near the face of one pincer would suffice.

For that matter, get a copper pipe cap from your local hardware or plumber's supply - the kind that solders on to cap off a pipe - then connect your cable to that and slip it over the end of the clamp. Nice flat surface, cheap, and "sacrificial" - when it pits too much or burns up, just spend another 79 cents and away you go.

trikeman
08-18-2011, 10:55 AM
You can also get clamps at your local welding supply house. I didn't like the clamp on my Miller Thunderbolt when I got it, so I had my local AirGas supply house put one on that I liked. The cost wasn't much more than $10.

If you already own the vice grip clamp, you have little to lose trying your idea out. The biggest problem you will have is getting that large size stranded wire to behave while you affix it to the clamp. At the welding supply, they had a nice machine that crimped the clamp end down nicely around the wire making a good connection. The copper wire leads on my Thunderbolt are about the size of your finger in diameter.

They also make some pretty inexpensive and cool magnetic ground clamps, that will attach to very large surfaces for less than $15.

Banshee
08-19-2011, 07:48 AM
Thanks for the input guys. As for the thickness of the ground wire(trikeman), sounds like you have a more heavyduty welder than me. the ground wire on mine isn't that thick, and the actual metal wire inside is probly only about 3/16" thick... also, the wire already has a fitted eyelett on it that bolts inside the cheapo clamp, so it would be easy to attach. as you said, nothing really to lose by trying it, so I think I will, and I'll just keep watch on it for the pitting you guys mentioned.

trikeman
08-19-2011, 08:50 AM
With the fitted eyelet, I think you are good to go, if you tighten it down good, I wouldn't expect the pitting to be too bad. I think all my welders (except for my Oxy/Acetylne torch or course) just have either eyelets or clamps just squeezed down on the wire, so there is no difference.

Ibedayank
08-19-2011, 10:42 AM
Banshee
I use the same type of clamp on a Lincoln AC 220....aka tombstone
up to 175 amps burning 3/8s rods and didn't have any arcing or pitting of my clamp
arcing/pitting of the clamp is normally caused by a loose ground clamp or not hooking it onto clean metal aka dirty or rusted
before putting on the clamp grind a spot down to shiny clean metal. Because its new metal does not mean its clean
look up mill scale.

Ibedayank
08-19-2011, 10:59 AM
2752275327542755
just a few styles of ground clamps available

Banshee
08-20-2011, 08:57 AM
So, I went to the local hardware/farm store yesterday and looked at other clamps... with the prices of $10-$25 I felt the vice-grips at $20 were best, since if they didn't work for this, then I'd be left with a useful tool... I also wasn't impressed with the other clamps size capasity(how big a piece they can clamp) another reason I was atracted to the idea of the vice-grips...

Instead of drilling through the clamp, I welded a piece of 1/8" sheet steel to the back and bolted the wire eyelet to that(see animated pic). I then wrapped the cord to the handle with Scotch Super33+(fire resistant) electrical tape.

After this, I proceeded to weld a headtube/downtube/gusset joint. This included two 3" long welds, and after all that welding, the clamp was only moderately hot. I could touch it within 2" of the contact points, and there was no discoloration on the contact points which suggests clean exiting/transfer of the electric...

All n all, I think this was a great success(well worth $20)

trikeman
08-20-2011, 09:33 AM
Good job. I am not sure why the jaws on that vice grip come to such a point, but you will get better electrical contact (more surface area) if flatten them a bit.

Ibedayank
08-20-2011, 10:20 AM
trikeman
its a vicegrip made for welding they are made that way

Banshee
08-20-2011, 12:32 PM
the smaller the contact, the closer you can get it to your weld...

trikeman
08-20-2011, 12:33 PM
the smaller the contact, the closer you can get it to your weld...

I agree, but keep in mind that the smaller the contact, the less amps it will carry too.

Banshee
08-20-2011, 12:50 PM
I agree, but keep in mind that the smaller the contact, the less amps it will carry too.

True, but this "solid" clamp is already more contact than the "hollow" shell of the original clamp...

trikeman
08-20-2011, 01:09 PM
If it works good, use it.

Ibedayank
08-21-2011, 01:15 AM
I agree, but keep in mind that the smaller the contact, the less amps it will carry too.


take apart the outlet that your welder is plugged into... now just how much surface area is carry that amount of power?
he is using a 120 volt mig welder that at most will draw 20 amp at 120 volts ..... at work i use a welder that draws 60 amps on a 240 outlet and have no problems with the ground clamp. Clamp it on tight and to good clean metal and go to town

trikeman
08-21-2011, 07:46 AM
The amount of current coming from the outlet is a lot less than the current at the weld clamp. That is what the transformer in the welder does - it converts high voltage low current input to low voltage high current output. But its all moot because it is working for him and you too, so obviously the small contact area of the sharpened points is enough to weld with.

Ibedayank
08-21-2011, 07:55 PM
hell any clamp has to be better than the POS jumper cable clamps they come with

Banshee
08-24-2011, 09:22 PM
The amount of current coming from the outlet is a lot less than the current at the weld clamp. That is what the transformer in the welder does - it converts high voltage low current input to low voltage high current output. But its all moot because it is working for him and you too, so obviously the small contact area of the sharpened points is enough to weld with.
It's not a sharpened point, from the side you see the rounded profile, but if you seen from the front, they have about 3/8" of flat contact...

Banshee
08-31-2011, 03:22 PM
well, after 12 hours of welding(on and off, of course) the other day, there isn't so much as a black mark on the contact points, and my welder only rated at 20% duty cycle never got over heated, so I'm convinced this was a great conversion...

trikeman
08-31-2011, 05:29 PM
Good job Banshee. I am glad its working out.

Ibedayank
09-01-2011, 08:32 AM
banshee

now you know we need to see pics of said welding as proof ...

Banshee
09-04-2011, 02:53 PM
banshee

now you know we need to see pics of said welding as proof ...

LOL, well that's kinda impossible, sinse one thing was an exhaust pipe on a friends vehichle who was leaving the state the next day, and the rest of the welding was body work for a friend who lives an hr away, and the next time I see him, that will be bondoed! when I get around to some more chopper porojects, I'll be sure to get pics. I'd like to get oppinions on my welding anyway. Hopefully soon, but I been really bussy lately...

Banshee
09-13-2011, 03:03 PM
Here's a bit of that welding, got playing around with scraps and made this cool little emblem(about 4" tall, made from 1.25" square tubing):

trikeman
09-13-2011, 08:11 PM
Nice work.

Banshee
09-13-2011, 11:38 PM
thanks, i'm thinking have that off the back of a chopper at the end of an "s"-curved tube, nice *****'s tail. lol

trikeman
09-14-2011, 11:27 AM
It reminds me a lot of some of GSGoehl's he does with oxy-acetylene on several sculpture videos I like to watch

http://www.gsegmedia.com/free%20videos/index.htm