Get Ready to Laugh

At the risk of repeating some of what Zorro said - if you clip the clamp to your metal table and then lay your workpiece on it, the work piece and the table should form a circuit so the current can flow from the rod to your workpiece to the table and finally back to the clamp. Where this doesn't work is the situation when rust or some other coating prevents a good contact to be made between the workpiece and the table - remember, the contact area betweent the workpiece and the table have to carry the full welding current. Sometimes you will see sparking at the junction of the two and will get pitting on the surfaces caused by the arcing. If this happens then you can put the clamp directly on the workpiece or make a better contact with the table.

Putting the clamp on the workpiece is the best but often the weight of the clamp and cable make aligning pieces difficult. The welding circuit is not referenced to ground so current should not be trying to flow to ground. You should be able to touch the stinger and a ground and not get a shock (I do NOT recommend you try this in case there is some poor insulation) but if you touch the bare tip of the rod and the clamp you will get a tingle from the

50-80 volts. Good electrical practice says to keep your gloves and boots dry when handling the clamp or the stinger when the welder is turned on since they will provide insulation for your body.

Zorro brings up a good point to repeat since it can cost some needless expense if forgotten. If you are welding on a car put the clamp as close to the weld area as possible so the current through the car body can go directly to the clamp with the absolute shortest path. This greatly reduces the chance of currents getting into sensitive electronics. Some weldors disconnect the battery also. If you are welding on something like a wheel hub make sure the clamp is on the hub not the car frame so the current does not have to pass through a bearing to get to the clamp. The current flowing through the bearing rollers/balls will likely arc and cause pitting.

In other words no matter what you are welding (including on your table) think about how the current is going to flow from the rod back to the clamp!

billh

Reply to
billh
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Earth ground has no mystical magical qualities with respect to electricity, particularly not to electricity which is transformer isolated from the mains. Current flow requires a completed circuit *from* the source, *through* the load, and *back* to the source. Earth ground is not involved. An Earth ground doesn't "soak up" electricity. It is simply a large sheet conductance which *may* serve as an alternative conductor for electrical current back to the service entrance connection under certain *fault* conditions (for example a short between the primary and secondary windings of the welding transformer).

To illustrate this, once you have your welder hooked up, try to strike an arc to Earth (dirt, concrete floor, etc). Nothing will happen. There isn't a complete circuit, and no current will flow. Now try to strike an arc to some metallic piece which has the welder return clamp attached to it. Boy howdy, now you get some action.

As the old electrician used to say, "It takes two wires to make a light."

Gary

Reply to
Gary Coffman

It will be under

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Reply to
Don D

ViseGrip or their generic equivalents. The cheap ones will do because they will acquire spatter drops when used to hold things together while tacking.

Another safety item - 5 gallon bucket filled with 2-3 gallons of cold water. There's nothing quicker to chill hands, etc. which have come in contact with hot metal than to shove them into this bucket. It's also handy for putting out something that has caught on fire.

I frequently work outside, so I hose down the surrounding grass before starting. I try to keep the burn spots on the lawn small by:

- keep the grass trimmed short

- leave a water hose trickling

- be prepared to turn on the sprinkler system zone

You WILL set things on fire. Figure out how to douse the flames before they occur. You WILL burn your skin at some time. Have a plan for it.

Reply to
Thomas Kendrick

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