Thread: Safety Question

Hi,

The twist holders have adjustable clamping force onto the electrode by way of the twist, the clamp style have fixed clamping pressure. The clamp style are usually bundled with cheap end equipment to keep costs low for the manufacturer.

You can change live electrodes safely whilst wearing welding gauntlets and whilst not being in contact with the return path of the circuit. If however you are welding an object on which you are standing then the highest level of safety is achieved by turning off the machine.

To avoid shock and burns you should do the following,

1. Wear a leather jacket and leather welding gauntlets, leather boots with rubber soles, flame proof / fire retardent fabric for pants. Never allow bare skin to be exposed to the welding surface. Always shield your entire face when welding, wear safety glasses beneath your welding helmet and weld in a well ventilated area. Intense UV light is emmited from the welding arc and this can cause rapid damage to eyes and skin.

There is a safety guide here General Welding Safety Guide which is an old one but still relevant.

Regards
Pete Tokentools

Originally Posted by lilcuda

Hello , I am new to welding and have just bought a BOC Smootharc 130 to start learning MMA.

I wanted to ask about the electrode holder and safety relating to this. Are the twist holders better insulated and therefore safer than the clamp style holder.

How is the best way to change electrodes , should the machine be turned off each time ?. I read the electrode can be grabbed where flux coating exists .

What are the general rules to avoiding shock when welding .With working at a steel bench should there be insulation when leaning on the bench to avoid becoming part of a live cicuit or is this to protect from the heat of the work piece .

Thanks .

Thankyou for the info Pete .

If I upgrade my cable set should I buy cables that are close to the machines output or can I install say a 200 amp set without problems ?.

The cable and electrode holder that comes with the BOC 130 are absolutely fine and perfect for a beginner welder to start laying some beads.

I've got the same welder as well as a UniMIG, which has the twist-style holder - I use both and have no preference for either, or at least not enough to go changing holders.

Originally Posted by lilcuda

Thankyou for the info Pete .

If I upgrade my cable set should I buy cables that are close to the machines output or can I install say a 200 amp set without problems ?.

You can install larger capacity cables, I have found people doing so tend to go for longer sets at the same time otherwise increasing cable capacity and keeping length the same is of little benefit.

Regards
Pete

Originally Posted by lilcuda

Hello , I am new to welding and have just bought a BOC Smootharc 130 to start learning MMA.

I wanted to ask about the electrode holder and safety relating to this. Are the twist holders better insulated and therefore safer than the clamp style holder.

How is the best way to change electrodes , should the machine be turned off each time ?. I read the electrode can be grabbed where flux coating exists .

What are the general rules to avoiding shock when welding .With working at a steel bench should there be insulation when leaning on the bench to avoid becoming part of a live circuit or is this to protect from the heat of the work piece .

Thanks .

Hi lilcuda & welcome,

Through my career, the electric shock received from a welder was always called a boot. I certainly have received my fair share of them.( please ignore the cries about me, from the peanut galley, "So that's what wrong with you then Grahame?" )

A boot comes about because of the electricity taking a short cut through your body, which is mostly moisture anyway.

The trick is to identify the potential points of entry/exit and take precautions against shock.

The current can route through your body from a number of places :
• A burn in welding cable insulation
• A loose screw in the hand piece, - which can make contact with your damp glove –
• Loose cable connections, ie cable to hand piece.
• Leaning against the steel weld bench –especially with damp clothing
• Perspiration saturated clothing

• Contact with the electrode clamped in the hand piece ,puts you in contact with live current, normally up to 80 volts. Electrode flux can carry current if it is damp. Keep your electrodes dry.

Current leaving your body:


While I do wear safety boots, just walking about in them ,they do get wet. Welding for all of the day the gloves (good quality Big Red l/s jobbies) get damp through sweat. On rainy days,I drag a dry rubber mat to where. I stand at the bench..

• Keep your boots dry
• Lay down an insulated mat to stand on - old conveyor belt
• Damp gloves-keep a spare dry pair and rotate them

If changing electrodes concerns you, by all means turn off the mains while doing so,though the current will be still there while you weld,so the precautions remain necessary.

Sure stick with the basic rules plus some extras for wet weather.
I hope this helps

Cheers
Grahame

Thanks guys , all useful info .

If I was to change the electrode holder it would be with longer leads so I will see how I go and than upgrade if i want the machine further away.

I was curious to leaning on the bench as Grahame points out as in the videos I have seen they have used this to balance themselves but I wondered if this also has current .

If you are using a basic arc welder plugged into a 240V - 10A socket then the nominal maximum power drawn by the welder is 240 x 10 or 2400 Watts.

If your welder is set at 100 A the the voltage can be no more than 2400/100 or 24V - this is not going to do much to you in terms of electrical shock. (I used to get my physics students to briefly feel this so they know what it feels like - these days we are not permitted to do this). Bear in mind that these numbers are nominal and as Grahame says the volts can be up to 80V and this will give you a bit of a boot but unless you have some other medical condition it won't do significant damage.

One of the greater potential electrical dangers when welding is to watch out where your hot electrode is when you put it down. In my early days I let the electrode touch the mains power cable to the welder and it melted thru the insulation shorting the cable and tripping the breaker. These days I hang an occy strap from the roof and at the end of the occy I hang a triangular shaped piece of 1/4 steel rod (like a musical triangle) and when I finish and run I poke the hot electrode thru the triangle (hot electrode pointing away from me) and hang the hand piece from the triangle. This means it is not electrically connected to anything and I know it won't burn anything and is handy for my next run.

Originally Posted by lilcuda

If I was to change the electrode holder it would be with longer leads so I will see how I go and than upgrade if i want the machine further away.

Ring up one of the welding supply shops out of the phone book. Tell them what brand and model the machine is or better take the existing cables to the welding shop.If the fittings are re usable( Does the 130 have Dinse connectors -if so be warned they come in different sizes) ) ,ie will unscrew and can be screwed on to another set of cables you save $. You should be able to buy cable off the roll. Given the current price of copper I think you may get a shock.

In spite of that, the 130 amp machine is quite light and so, could be picked up and positioned over the welding area with cables draping down and 240 input well out of the way. I would suck it see for a while before getting longer cables.
You don't want it too far away as you will need to change amps and will get annoyed going back and forth over any distance.

Grahame

I was thinking about some sort of electrode holder stand that could be mounted either on the table or on a welding cart so it was safely away .

Something that could hold the stinger in one place so it didnt unexpectedly swing into your face or other potential danger .

With the electric shock side of things I thought the amps would have been the main worry .

Originally Posted by lilcuda

Thanks guys , all useful info .

If I was to change the electrode holder it would be with longer leads so I will see how I go and than upgrade if i want the machine further away.

I was curious to leaning on the bench as Grahame points out as in the videos I have seen they have used this to balance themselves but I wondered if this also has current .

By all means use your body to brace yourself. Just put adequate heat and electrical insulation between you and the arc and current.

A technique that works for me is to use my left hand index finger as a bridge to rest the stick on .Quite often I will grind the bench to clear the spatter off ,so my hand ( in glove ) can easily slide parallel to the weld - and not catch on the spatter.

The electrode slides over the horizontal formed by my gloved finger as I move and it is consumed by the arc.

This means there is not much distance between me and the arc - usually about a 100 mm- maybe too hot for some but you used to it. This enables good stability of the arc and a resultant good bead appearance.

Grahame

I'll chime in again and note that the BOC 130 is a welder you can sling over your shoulder, not something that needs long leads.

As for voltages, despite having a nominal 10A lead, I can assure you it draws well in excess of 10A, but it's aggregate draw combined with duty cycle probably falls within the allowance for a 10A plug. Also the open-circuit voltages is far higher than the voltage under load, due to the impedance of the welder.

That said, the voltages involved are modest, but nevertheless can be hazardous - unlikely to electrocute you, but may give a nasty jolt, particularly if you're damp.

Originally Posted by RustyArc

I'll chime in again and note that the BOC 130 is a welder you can sling over your shoulder, not something that needs long leads.

As for voltages, despite having a nominal 10A lead, I can assure you it draws well in excess of 10A, but it's aggregate draw combined with duty cycle probably falls within the allowance for a 10A plug. Also the open-circuit voltages is far higher than the voltage under load, due to the impedance of the welder.

I just measured my GMC plain arc welder and the open circuit V is 44V AC (<1 DC) with a 3A no load mains current. The mains draw current under load is 24 A (eek!) - why the hell it doesn't throw the breaker I don't know?

My inverter open circuit is 92V DC (<1 VAC) - I can't check the current draw because my breakout circuit doesn't have a 15 A socket on it - yet!

Originally Posted by BobL

The mains draw current under load is 24 A (eek!) - why the hell it doesn't throw the breaker I don't know?

Because breakers aren't just defined by a particular current, rather they have a trip curve - you'll notice that the breakers in most domestic fuse boxes are "C" curve, and it's worth looking up over what time a C-curve breaker will trip with various currents - the brief version is that you can draw *many* times the rating of the breaker over a short period of time without it tripping.

This actually isn't dangerous - breakers are designed to protect the cabling, ie. trip before the cable heats up to a point where there's risk of insulation breakdown and ensuing fire. Now, cable doesn't heat up instantly, it's a function of energy over time, so that's the logic of the breaker's trip curve, and why you can use very high intermittent loads on a nominally much lower-current circuit.

Note that breakers have 2 trip characteristics, thermal and magnetic. Very high currents, ie. from a dead short, will trigger an instantaneous magnetic trip.

Originally Posted by BobL

I just measured my GMC plain arc welder and the open circuit V is 44V AC (<1 DC) with a 3A no load mains current. The mains draw current under load is 24 A (eek!) - why the hell it doesn't throw the breaker I don't know?

My inverter open circuit is 92V DC (<1 VAC) - I can't check the current draw because my breakout circuit doesn't have a 15 A socket on it - yet!

Wow, 92V = Deadly. The Aus standard states a maximum of 80VDC.

John