Isn't a steel welding table dangerous ??

[chela]

Hi all,

This might be a silly question.....but aren't steel welding tables dangerous - potential for electric shock ???

I know people wear leather and steel is needed so that molten metal and sparks don' t burn and start a fire on the table - do you guys earth your tables ??

Please enlighten me, i'm starting to TIG weld and watch all the guys on here leaning on their tables and hand holding the filler - wouldn't this be risky ??

Apologies in advance for the dumb questions

[Moz]

Hi Chela,

It's one of those "if 5 other things go wrong it could be a problem". Welders use a pretty low voltage - 50V tops, the MIG guys usually run about 10-20V AFAIK. And there's a direct path between the welding electrode and the return lead, so almost all the current will flow through there. Since you should also be trying to keep the path from the clamp to the weld short, you won't have much current outside that part anyway. As well, most people try to avoid touching the electrode when they're welding :)

To get a decent shock you'd need to hold the return clamp in one hand and the electrode in the other, then trigger the welder. Just touching two parts of the table will not give you enough current to matter in most cases. It's still not something you should do, just in case.

[zapster]

It's a lot better than a wooden one..:blob2:

...zap!

[tresi]

If you're doing ac TIG with high freq you'll light yourself up plenty of times steel table or not. Leather jacket for TIG? maybe if it's cold in the shop.

[DesertRider33]

I welded on a steel jig 40 hrs or more a week for 4 years and never got shocked. I weld on a portable steel table in the garage and have never been shocked. I have welded on cars and other metal structures and never been shocked, for 15 or more years. I dont go grabbing the electrode in one hand and the ground clamp in the other with the weld power on while wearing soaking wet clothes, so maybe if I had done that I woulda been shocked by now.

[Oldgeezer]

Yes, a steel welding table should be earth grounded. That being said, electical safety doesn't hinge soley on having a ground. You should always keep in mind that there is a potential for electrical shock when using powered equipment. Electrical cords should be in good shape, outlets should have proper circuit breakers, etc.

[tresi]

It's a lot better than a wooden one..:blob2:

...zap!

When I interviewed for my job the shop was bare. When I started 2 weeks later my boss had his carpenter build wooden benches. They usually go out by themself but I've ripped the vise off twice. I have a vise mounted on the truck for now. I have a nice piece of 1" AR400 waiting to become a benchtop.

[William McCormick Jr]

Hi all,

This might be a silly question.....but aren't steel welding tables dangerous - potential for electric shock ???

I know people wear leather and steel is needed so that molten metal and sparks don' t burn and start a fire on the table - do you guys earth your tables ??

Please enlighten me, i'm starting to TIG weld and watch all the guys on here leaning on their tables and hand holding the filler - wouldn't this be risky ??

Apologies in advance for the dumb questions

While AC TIG welding on aluminum, you should probably have an aluminum welding table, to stop contamination. However if you put your bare arms on the table every now and then you will get a little tingle in your elbow. I have never been hurt by it.


One thing you should never do is put the work piece to be welded on other junk resting on the table. If you dunk your tungsten and it solidifies in the work, often just out of fear of ruining the part or realizing it late. You can make a quick movement and lift it off the table before you take your foot off the pedal. If your table is cluttered you can get some pretty wild ARCing going on. Probably won't kill you though.

And never leave spray cans and a bunch of welding wire on the bench.

Sincerely,


William McCormick

[zapster]

Yaknow William..

Your almost starting to make sence..

Whats going on here???


...zap!

[joethemechanic]

the only time I have gotten a shock while welding was when I was working in the rain and my gloves were soaked.

Although if you are welding on something that is touching the ground, and you drop your electrode holder a short distance away, and the rod in your holder just happens to be in contact with the ground,,,,,,,,,,,It shocks the worms, I don't think they like it much, because they all come up to the surface and wiggle around. :)

[Oldtimer]

I've welded on steel tables for over 40 years and never been shocked. I've crawled around on streel structures welding on them and never been shocked. I've sat astraddle of firetubes welding on them and never been shocked. I have welded in the rain on the back of truck and had the crap knocked out of me starting and breaking the arc. It didn't take long for me to learn to strike the arc and weld, not scratch the rod and wait for the machine to rev up. When you broke the arc just drop your stinger and let it break itself. Then pick up the stinger after the machine idled down and change your rod.

[deadman1474]

the first job i ever had we were making racks for gm. and we were standing in puddles because the shop leaked with minimal safty gear and leainin on a steel rack we were welding. im still here

[smithboy]

I've shocked the bejesus out of myself before with high frequency, but never with the welding current. I have had a tingle from ac stick welding, but nothing so bad I stopped welding, but then again, I try not the ac weld in poor conditions (excessive moisture, mud, bare skin touching the floor or ground or anything like that) . I have never so much as gotten a tingle from DC.

On another note, i have dischared a 600v (I think) welding capacitior into myself through a screw driver...I would recommend NOT doing that.

[chela]

Ok,

I'm off to make my steel welding bench.....going by all the advice you have kindly given ....i should be right as long as I use my common sense :)

Thanks, and happy welding to you all !!!

[DSW]

I work with comercial divers and we weld in what be called "wet" locations. DC only and we always make sure that the ground is on the side away from the diver, never behind him, so that he is unlikely to become part of the circuit. Oh and BTW the welder always states when he's ready to weld and we energise the circuit and tell him he's good to go. We shut it down after he says he's finished so he can change rods or chip and again we tell him its off so theres no confusion or accidents.

[65535]

It's good practice to run a main ground clamp to your work surface, then run a smaller clamp to your workpiece, but it has been said before, welding voltages are well below the potential that is required to get lethal current to the heart.

[Burnit]

Like the others I have welded inside and on top of all types of stuff. The only thing that has ever shocked me was faulty leads.

[Patriot Performance]

Other than my rod clamp having that little screw that bites me once in a while. Never a jolt from a table. Especially not while mig welding.

[William McCormick Jr]

It's good practice to run a main ground clamp to your work surface, then run a smaller clamp to your workpiece, but it has been said before, welding voltages are well below the potential that is required to get lethal current to the heart.

White lighted gases have the potential to deliver 30,000 volts, if allowed to fill a capacitor of some kind.

Or if the ARC hits a dielectric surface, the other side might jump up to a very high voltage potential, like a capacitor. Most of the time you do not get these situations. When they occur it is almost always because of rust.

Rust acts like a dielectric in a capacitor, and turns the rusty plate into a capacitor plate. High frequency from a TIG machine can do this. A lot depends on the size of the part you are welding. However you can also do it with an ARC welder as well, if rust is involved.

Dry I can hold up to 400 volts DC across the skin on my hand. Yet while welding a rusty part, I received a rather powerful jolt, as a rusty part started to ARC to the ground. There was no other power then the welder. Yet I got shocked by high voltage. The part was painted, I only had one hand toughing the part. And I had the same work boots that functioned well the rest of they day without problem. It is rust.

Lead can become a capacitor plate on the other side of a dielectric circuit board. I have done some experiments with glass and lead, and I was able to create a lightning like bolt, of basically lightning, that could pass through the cuff of a welders glove and into the work table about one and a have inches away from the object being charged. I did it with high frequency from the TIG welder.

But I weld on steel tables all the time. I just try to sand them down before I weld.

Sincerely,


William McCormick

[redhatman]

It's a lot better than a wooden one..:blob2:

...zap!

True. I have caught fire to my bench several times.... Nothing major though.

[MAC702]

...Welders use a pretty low voltage - 50V tops, ...

There's a helluva lot of 70 - 90 V OCV Stick welders out there.

But unless you clamp the work lead to your leg you're pretty safe.

I've been shocked once pretty well. I was holding a large steel attachment to a billboard. The arc struck on the attachment before it got into good contact with the billboard where the work lead was. I had my stomach touching the billboard and my bare hands touching the attachment. That was a good recipe for shock.

Other times I've felt tingles was changing the electrodes in the rain when I was soaked and in the dirt with the weldment. Even in these conditions you can be safe if you watch what you are doing and keep your gloves dry.

[arcflashlynn]

If you're doing ac TIG with high freq you'll light yourself up plenty of times steel table or not. Leather jacket for TIG? maybe if it's cold in the shop.


I agree... it would have to be pretty cold for me to wear leathers while doing Tig... Or even a welding jacket for that matter,... i dont like them. haha:angel:

[redhatman]

IIRC, voltage is more of a zap, but amps are what kill you. Welders have a huge potential for lots of amps, and yet you only need like 1/2 amp to kill you?

[MoonRise]

What kills you from electricity is the right, or wrong, combination of voltage and current and circuit resistances and frequency. All those factors come into play. Ohm's Law applies as well, because it states the relationship from voltage and current and resistance.

E = I x R (or for the whippersnappers V = I x R)

A standard 12V car battery can kill you. Normally, your skin resistance is high enough that the limited 12V coming from the battery can't push a fatal or dangerous current through your body. But -IF- that resistance is lowered, watch out! What can lower the resistance? Sweaty skin, or a fresh bloody cut/wound, or really bad is a burr on the terminals puncturing the skin on the thumbs and making contact with the blood -in- the body. From one thumb through the heart to the other thumb = death. So don't put your fingers ON the terminals!

Fatal shock level can be as low as 60 milliamps from 50-60 Hz 120-240V AC power due to cardiac fibrillation (the heart muscle just spasms and twitches and doesn't pump the blood, no blood flow means you die). For DC, directly fatal current levels are generally in the 300-500 milliamp range.

But if electrodes have good connection into the body (see the above mention of the battery terminal burr into the thumbs), fatal current levels can be as low as 1 milliamp!

Indirect electrocution hazards could also be involved via startle response and a fall or crash (off of a ladder or into another machine, for instance), or muscle lock-up could occur and current could continue to flow resulting in tissue damage via heating/burns.

High voltage and/or high frequency have addition effects and dangers.

A steel or metal welding table is generally not dangerous in itself. It is safer than igniting a wooden table! Don't make yourself part of the welding circuit and there is minimal danger. Wear welding gloves (dry ones) and you have reduced a major shock starting point, as well as protecting your hands from the arc and from the hot metal.

[hankj]

Electrocution requires a current flow through the heart muscle of sufficient strength to disturb the heart rythm. A few milliamps are enough.

In order to develop that current, sufficient voltage must pass through your body in a way that carries it through the chest. A path like left hand to right hand would be a bad thing, but foot to knee not so bad.

The GMAW and GTAW processes do not have enough open circuit voltage to push that fatal amount of current through you. SMAW, on the other hand, often has OCV's of up to 86 volts. That can do the trick under the right circumstances.

If you are the path of least resistance for the current to ground, zap, you get hit. The amount of current that will flow through you will only be a portion of the total current, unless you are the only path!

Most often, the damage to the weldor happens due to the reaction from the shock! The sudden body movement associated with electric shock makes us bang into things, fall off of ladders, etc.

Adherence to proper practices virtually eliminates the possibility of shock. And, the oftentimes felt bite of HF energy while TIG welding does not have enough current flow to hurt you.

Finally, steel tables are the industry standard.

Hank

[William McCormick Jr]

What kills you from electricity is the right, or wrong, combination of voltage and current and circuit resistances and frequency. All those factors come into play. Ohm's Law applies as well, because it states the relationship from voltage and current and resistance.

E = I x R (or for the whippersnappers V = I x R)

A standard 12V car battery can kill you. Normally, your skin resistance is high enough that the limited 12V coming from the battery can't push a fatal or dangerous current through your body. But -IF- that resistance is lowered, watch out! What can lower the resistance? Sweaty skin, or a fresh bloody cut/wound, or really bad is a burr on the terminals puncturing the skin on the thumbs and making contact with the blood -in- the body. From one thumb through the heart to the other thumb = death. So don't put your fingers ON the terminals!

Fatal shock level can be as low as 60 milliamps from 50-60 Hz 120-240V AC power due to cardiac fibrillation (the heart muscle just spasms and twitches and doesn't pump the blood, no blood flow means you die). For DC, directly fatal current levels are generally in the 300-500 milliamp range.

But if electrodes have good connection into the body (see the above mention of the battery terminal burr into the thumbs), fatal current levels can be as low as 1 milliamp!

Indirect electrocution hazards could also be involved via startle response and a fall or crash (off of a ladder or into another machine, for instance), or muscle lock-up could occur and current could continue to flow resulting in tissue damage via heating/burns.

High voltage and/or high frequency have addition effects and dangers.

A steel or metal welding table is generally not dangerous in itself. It is safer than igniting a wooden table! Don't make yourself part of the welding circuit and there is minimal danger. Wear welding gloves (dry ones) and you have reduced a major shock starting point, as well as protecting your hands from the arc and from the hot metal.


One that got me was, sticking an aluminum welding wire into a molten hot corner I was welding in.

It was so hot I had trouble focusing the ARC in the corner. I had the aluminum rod ready to jab into the corner and finish the stupid thing. When I kind of went to lean on something and I fell back a bit. I pulled the torch away, while I was moving the welding wire hand closer to the part, to catch myself. I stuck the welding wire into this very hot area, while the torch broke contact with the work. The high frequency engaged and it connected and broke a couple times. All in the flash of an eye.

All I knew was that I had just gotten the best shock I had ever gotten. My heart stopped. I was loosing blood pressure and consciousness. Most people probably do not realize what happens when your heart stops. It is like you are a deflating blow up Christmas lawn ornament.

My heart hurt bad. I was no longer able to stand up. And just as I started to laugh about the fact that I might really die right now. I realized what I did. I was beaming into a microwave horn basically. And I stuck a molten aluminum conductor into the horn.

Wow that hurts.

But I believe the principle is that the aluminum welding wire in that super heated area melted on the outside, creating a liquid diode. Basically a capacitor. I became part of the capacitor. It hurts.

If this ever happens just laugh. It loosens your heart right up.


Sincerely,


William McCormick

[zapster]

Are we about done here??:waving:

This was about steel tables at first but yet once again there has been a major Train Wreck on the track..

No more near death experiences on the Man's Thread OK?

...zap!

[tnjind]

zabster,
I think this is good info and kinda along the lines of the steel table question.

[Roy Hodges]

Every big fab shop has steel welding tables . they consider the bigger, the better . In the fab shop (shipfitter shop) in Mare Island naval shipyard ,the whole floor was steel, except for the aisles . And they also had huge pin slabs , built in as part of the floor. Inside the building was about 5 acres,under one roof. At Kaiser Steel, in fab shop , we worked on top of steel I beams on floor , that had the tops machined to be flat &level for assemblies about 50feet wide &up to 100 feet long . all this metal was ground to building -etc. No problems .

[Brett]

But unless you clamp the work lead to your leg you're pretty safe.




I really like that reply Mac!

[bhardy501]

The only time I ever got shocked was in school welding pipe that was tacked onto a steel pole off a steel table hooked to a steel divider wall. My rod stuck to the pipe and I was leaned up against the metal wall. Well my shirt had rode up and I was touching bare skin on my lower back to the wall. When I moved I got a pretty good jolt to my lower back through the wall. It didnt hurt me and boy was my back muscles relaxed after that. It did get my attention rather quickly though.

[wlbrown]

HELLO TO ALL,
when i got my tig machine, i was getting a shock.
i called my electrician friend, and he said to run a
ground wire from the table to a ground inside the
electric box that supplied the machine. i did this,
and have had no problems since.
good luck to all.
wlbrown

[Joker11]

In college during an Advanced Tig class someone let a cooling hose leak. I didn't know it was leaking. I was in another welding booth. It filled a low spot on the floor exactly where my steel toed boot was standing. I got a shock from my leg to my arm on the table. Felt realllllly good.

I pay attenting a lot better now.