Thread: Safety Question

Originally Posted by RustyArc

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.

I made some enquiries when I was replacing my old style switchboard with new and was told that a D curve breaker is better for welding so I fitted one of those to my shed circuit. Not sure if this is correct or not but have not had it tripped by the welder. An old 130A. When I bought this welder second hand the previous owner had it fitted out with new cables and an earth clamp. Apparently thanks to the SA govt. The cable is 35mm. The work cable is about 5m long the earthing cable about 4m. The only problem is the weight of the cable.

Dean

Originally Posted by Oldneweng

I made some enquiries when I was replacing my old style switchboard with new and was told that a D curve breaker is better for welding so I fitted one of those to my shed circuit. Not sure if this is correct or not but have not had it tripped by the welder. An old 130A.

D curve breakers are often used in industrial or workshop situations where there's greater peak currents from motor starts etc. That said, I doubt a 130A welder would trouble a normal 16 or 20 amp circuit with a C-curve breaker, unless it has a particularly high duty cycle, and you're using that duty cycle to lay down long, high-amperage, welds.

Originally Posted by BobL

Very interesting. This might explain why my 3HP DC trips the 20 A breaker on one breaker box but not on another?

It's worth checking what the curve is on the different breakers (whether it's C20 or D20) and whether there's other loads on the same circuit that are adding to the total load the breaker is seeing.

Back to the original question, I positively hate tong type electrode holders, particularly the ones that come with the Smootharc machines, (if they are all like the one I used recently). Tong type electrode holders do not hold the electrode nearly as well and the damn things seem prone to moving at the most inopportune times such as when striking an arc. This problem is typically worse when using smaller electrode sizes due to the lesser clamping force applied. So a clamp type holder for me.
As has been already said by many, moisture is the biggest factor as far as electric tingles go, your machine probably has a VRD (voltage reduction device) so is safer in this regard.
To be honest, I would rank the risks and their controls as follows:
1/ Arc radiation - eyes and skin, so wear safety glasses, don't tack up without a shield, cover exposed skin and wear sunscreen if working in a highly reflective environment. Button your shirt/overalls up to the top or second button depending on fit.
2/ Burns - eyes and skin, wear safety glasses especially when chipping slag, wear long leather gloves with a lining (this gives better protection than the el cheapo straight leather variety) and appropriate clothing - non synthetic, leather boots with clothing not tucked in the top and when working out of position consider leather skull cap and jacket. Button your shirt/overalls up to the top or second button depending on fit.
3/ Noise - hearing loss, use hearing protection when working with metal, every process with the possible exception of welding can and will produce noise at a level high enough to permanently damage hearing.
4/ Fumes - respiratory tract, beware of working in the shed in winter all shut up. Use appropriate ventilation - even a household fan can stop fumes accumulating. Consider a mask/respirator if severe enough, there are masks and respirators that fit under a welding shield and have suitable filter media for welding fumes. Take extra care when working with galvanised/ duragal products, fumes from these products are seriously bad news - look up METAL FUME FEVER. As with all things, dangers are directly proportional to exposure level. Take extra precautions if you or others are prone to asthma or other respiratory complaints. If fumes are building up, do something about it.
5/ Fire/explosion - body and environment, keep work area clear of flammable materials, beware of frayed clothing that could ignite. Before you strike an arc, consider what you are working on, did/ does it contain flammable materials, is there a fuel line near that bracket you are welding on the ute, is there oil soaked insulation on the other side of that panel you are welding on the car? Is there an LP gas tank or cylinder near where you are working on the car or caravan? Have a good dry chemical extinguisher in your work area where you can access it if need be. Know how to use it and occasionally check the gauge and upend the extinguisher and shake it so the powder does not pack down tight - if you cannot feel the powder moving either get it sewrviced or replace it (don't throw the old one in the bin either as it is a pressurised vessel and could explode in the garbage compactor).
6/ Electric shock - cardiac arrest and burns, work in a dry environment with dry gloves, check all leads both on the output side of the welder and the extension leads supplying power to your welder. Beware of dragging leads over hot metal surfaces that may melt them and keep them clear of areas where components may drop on them causing cuts etc. If you find a damaged supply lead, (welder, extension lead or power tool), cut the male plug off straight away so it cannot be inadvertently used. Don't use the old insulating tape fix. Turn off welders and powewrpoints when not in use.Do a first aid course and encourage others in your home/worksite to do the same.
If you ask yourself the following question for any task that you perform and then decide if they exist, what you will do to control the risks you will cover your bases fairly well.

1. Can I be caught in, on or between anything.
2. Can I strain or overexert myself.
3. Does anything need to be isolated or tested for dead (power, batteries, pressurised pipes, gas lines).
4. Can I come into contact with something that may harm me - gas, electricity, heat, noise, fumes or stored energy (water or gas under pressure, tensioned springs).
5. Can I damage any equipment.
6. Can I fall.
7. Can I slip or trip on anything.
8. Is there a chance I could spill or pollute something - oil, fuel, chemical.
9. Am I concerned that something may fall on me or strike me.
10. Do I need to communicate to others the risks associated with this task, (bystanders/helpers/neighbours)
11. Could there be any uncontrolled movement, (objects falling, rolling in an unintended fashion).
12. Am I using any substances harmful to my health.

Crikey Karl that's a very comprehensive OSH post.
Seriously - that's a good post.

Regarding fumes, I have been using my welding bay/fume hood a fair bit recently and it works really well.


You can also see my occy strap and triangular holder for the hand piece hanging from the ceiling to the right of the fume hood in the second picture.

I even have a reminder, the smoke alarm. It's about 6 m away and if I forget to turn on the exhaust fan the alarm sounds within about 60 seconds of making my first run. If I have the fan on and weld under the hood the alarm won't ever go off.

I can also use the fume hood as mini-spray booth, it also works very well for that.

I love your workshop BobL .

I haven't got the room for anything like that at the moment so will be doing all my welding outdoors.

I have most of my gear ready , auto darkening helmet ,couple pairs of gloves , safety glasses for chipping ,snood , apron . I bought a proban apron but wondered if this was enough for Arc .

Also going to get a jacket , is proban too light for arc ? . I was looking at proban with leather sleeve or just full leather ?.

Originally Posted by lilcuda

I love your workshop BobL .

I really like it too
Just setting it up in time for my retirement in 109 working days time, not that I'm counting or anything

I haven't got the room for anything like that at the moment so will be doing all my welding outdoors.

Unfortunately living in an inner city neighbourhood I'm sort of force to work indoors.

I have most of my gear ready , auto darkening helmet ,couple pairs of gloves , safety glasses for chipping ,snood , apron . I bought a proban apron but wondered if this was enough for Arc .

Also going to get a jacket , is proban too light for arc ? . I was looking at proban with leather sleeve or just full leather ?.

I find a jacket is too hot, especially for summer. I wear a long sleeved shirt, leather apron and a long leather glove that goes over the elbow on the left hand and a short one on the right.

What about angle grinding PPE? Full face shield and decent muffs?

BTW I have set myself (flannel shirt) on fire with an angle grinder, just under my right armpit!

I have a new set of muffs, getting some new boots.

I have grinding mode on my helmet but will be buying a full face for better visibility.

Good idea on the long glove , I can see the benefit especially leaning against a bench close to the work .

Originally Posted by lilcuda

I love your workshop BobL .

I haven't got the room for anything like that at the moment so will be doing all my welding outdoors.

I have most of my gear ready , auto darkening helmet ,couple pairs of gloves , safety glasses for chipping ,snood , apron . I bought a proban apron but wondered if this was enough for Arc .

Also going to get a jacket , is proban too light for arc ? . I was looking at proban with leather sleeve or just full leather ?.

I have a Proban flash hood and am very happy with it, but would use a leather shull cap in preference for all overhead work, other than that I am unimpressed by proban.
The best way I can put my response is to pose the question "when did you last see a boilermaker welder wearing an apron?" That is to say that aprons are rarely used in industry, at least in my experience.
Lets look at what you will be doing. Most of your work will be in the downhand position, therefore the risk of molten metal falling on you is low. If I were performing welding in the downhand position, my ppe would consist of the following, Headshield, safety glasses, combination overalls, leather boots and leather gauntlets.
I I were working overhead or horizontal, leather skull cap and leather jacket would join the list.
MMA is a fairly benign process and presents less danger from arc radiation than GMAW or GTAW.
Don't be scared of welding, particularly in a handyman context, there is a vast difference between burning 2.5mm rutile electrodes at 80A downhand and running 1.6mm fluxcore at 300A overhead. PPE is all relevant to the task performed, just as in motor racing there are differing requirements for targa events and fomula one.
You will most likely be exposed to more UV light from the sun outside than from the arc during your sessions.
To generalise, your greatest risk is probably the drive to and from your home to collect your electrodes and the steel you will require.

Originally Posted by Karl Robbers

. . . "when did you last see a boilermaker welder wearing an apron?" That is to say that aprons are rarely used in industry, at least in my experience. . . .

The main reason I bought an apron is not for the welder but for the angle grinder. As a novice I used to spend as much time with an able grinder as I did with the stick but these days I have to admit I'm not wearing it as much .

Originally Posted by BobL

The main reason I bought an apron is not for the welder but for the angle grinder. As a novice I used to spend as much time with an able grinder as I did with the stick but these days I have to admit I'm not wearing it as much .

Fair point BobL, I was probably a bit hasty with that comment as foundries are large users of aprons and I have worn them for specific tasks, (actually these were not welding related, I was feeding around 500 sheets of 5mm steel checker plate through a guillotine and then a brake press so overall wear was my primary concern).
Angle grinders are an interesting subject in themselves, few actually know how to use them properly and how to get the most from them. I see far too many people wearing the sparks all over their body when a slight repositioning would make the task far more pleasant. I am also firmly on the side of not wearing gloves when grinding, except in a few circumstances, due to the lesser control afforded by a gloved hand.
My feelings on the subject of steel toothed cutters on grinders have been voiced in many posts, so I will not bore others with them yet again.
I would go so far as to say that the most dangerous aspect of the whole welding/fabricating process is the humble angle grinder, yet it is possibly the facet of the operation given the least thought by most.
A couple of thoughts on grinder safety spring to mind.

• Don't ever use a damaged disc - destroy it and discard immediately
• Always use the correct disc for the grinder - correct bore size and the correct flanges, (primarily an issue with 7" and 9" grinders)
• Always aim sparks downward and away from other persons
• Don't lock triggers on
• Use two hands
• Guards are there for a reason, never remove them and adjust them to protect your hand if it should slip from the front handle
• Avoid using 1mm discs unless there is a specific need. To clarify this point, 1mm discs are not a general purpose disc, they are far more prone to breakage and must be treated with far more care so no side load is imposed. Hilti actually made a .75mm disc, but removed it from sale due to it being too "volatile"
• Use good PPE, in my opinion safety glasses are very borderline for grinder operations, a full faceshield or goggles are far better. How many realise that the clear lens of a welding shield is not actually rated for impact, I have never seen one fail, but it could be an interesting argument from a workcover perspective if one ever did.
• A grinder has a kickback potential greater than a chainsaw, particularly if a steel tooth cutter is used. Always work in such a way that the top 1/4 of the disc is not being used when cutting.
• Don't use any tool when intoxicated or fatigued. I lost a front tooth to a 9" grinder. I was really crook with the flu, shouldn't have been at work and was cutting a floor sheet out of an aluminium tipper body, the sheet sprung, causing the grinder to grab, kicking back and due to my depleted reflexes, strength or whatever I wore the side handle fair in the gob. 7 stitches, and a trip to the dentist later, I have a permanent reminder of what can happen.

Sorry if I rabbit on too much, but I am really passionate about this subject. Joe handyman now has access to some pretty serious industrial tooling, unfortunately, Joe has often never received adequate training on the safe usage of said tools.
I imagine that many A & E nurses would back up my thoughts on this one

i have an old lincoln "portable" 240volt jet which draws aprox 4400 watts start up current on a 3.2mm gp rod setting(flat out).didnt do slow blows or breakers at arc strike but will at 10 seconds into a heavy weld.yeah i know fellas,i dont use it any more!!!.