Thread: Old vs New Arc Welders

Gday
This link may explain things OHS Reps @ Work : Construction & Utilities - Compressed Air
thanks caveman

Hi all
You can not use compressed air to clean in a work shop .
As it is dangerious blowing dust around the shop major health hazard to the workers..
Welders,milling machines etc (eg car brakes) may have asbesto-containing materials.
You can not clean your self down with compressed air its a NO NO.
See work cover in your state about cleaning with compressed air.
My work is OHS
testing and tagging.
fixing tools replacing leads and service work on equipment.
This has been in place for over ten years in vic.
Tony
PS some very old welders do have asbesto in them. eg the old pipe warmer welder......
What does china put in them.....

Hi all
Spot on Captain caveman good one.
Tony

The idea that vacuuming or brushing is better that compressed air because of asbestos fibres or any other small particles is disturbing and make me wonder if OHS guys again even know what they are talking about. Asbestos fibres are so fine they will pass straight through most shop vacuum cleaner filters straight back into the workshop. Other than using a HEPA filtered vacuum cleaner (which do not have the air flow to pick up fibres floating around the air in a workshop) whether one is using a vacuum cleaner, brush or compressed air, the air in the workshop should be vented to the outside. When I blow stuff down in my shed the first thing I do us turn on my DC and open all vents, blow stuff down and leave the DC running for 20 minutes. I don't care much about the dust I can see, its the dust I can't see that's important and venting a shed or shop is about the only way to do this. Of course the bigger the shed the bigger then DC required.

The other reason compressed air gets a bad rap is because of so called air embolisms. But there is a BIG difference between industrial and hobby type compressors. Given the number of compressors in home workshops and users that don't know anything about air embolisms it's a wonder our hospital outpatient centres are not overrun with embolism patients. The reason for this is that 120 psi will simply not generate an air embolism through adult skin, unless you stick the air gun up your nose, or in your ear or into a wound that is close to a major blood vessel. It takes between 400 and 600 psi to place an air bubble in an artery and few home compressors can do this.

I treat compressors and cleaning by blowing, like using a table saw. Wearing ear muffs prevents you sticking the compressed air line into your ear and wearing a full face shield stops the crap getting into your eyes , don't push them hard up against soft skin or into broken skin and keep it away from other orifii. Simple stuff really.

I forget the % but the vast majority of air embolisms above water are not produced by hobby or workplace compressor users but by doctors deliberately performing body punctures with metal tubing.

HI
Dust ect in eyes is on top of the list .
Tony

Hey all

Most of the "big" engineering places I've dealt with have service tech come in every so often and guess what........ they blow them out with compressed air. Offsite if need be but it is still common practice. If your worried about it buy a machine that has an IP23S standard for work outside (eg lincoln V350 pro etc).
Alot of major manufacturers completely cover their electrics/boards, etc in a silicon type product to prevent damage from grinding dust... but as we all know it just get it everywhere and the only solution is a blowout or vac...

Cheers

Rappy

Originally Posted by antoni

Hi all
NO blow outs with compressed air now,
MUST use a vac to remove dust and dirt NOW.
Vaccum out check all leads ect ect, test and tagg
Before put back into service.
No compressed air to be used as cleaning tool .
Work cover...............................................................
Tony

Thanks for good advice, I hope this could make more awareness in the industry.

I still feel the amount of poisonous dust in a caravan work place because an "idiot" is maniac about blowing it's bench several times a day!
You can imagine how is the dust..... timber, glue and sometimes steel.

I know this isn't the timber forum but I know many people deal with timber and steel at the same time.

Originally Posted by antoni

Hi all
You can not use compressed air to clean in a work shop .

This subject should have its sticky because I don't think that too many people will look into this thread to know more about the risk of poisoning the work place

Your old transformer welder has an open circuit voltage of around 45 volts which makes striking the arc difficult and also as I have suggested previously, if the electrodes are damp, the arc will tend to snap out until the electrode is hot enough to remove some of the moisture. The latest technology inverter welders have a much higher open circuit voltage, up to 80 volts and supply almost pure DC. They restrike the arc much easier and Everlast give a five year full replacement warranty. Yep, I agree, don't aim your grinder so that the machine sucks in metallic particles, on the other hand, I have had to replace windings in old transformer machines which have had short circuited turns due to metallic grinding particles on the primary winding. I have always suggested that the covers should be removed periodically and the internals cleaned with low pressure air to remove any dust and metallic particles and at the same time check the terminal connections. Poor terminal connections create a high resistance joint which will conduct heat into the windings and burn the machine out. Also be aware of the duty cycle of your machine. If you don't understand duty cycle, look at the Technical Specs on the plate attached to your machine. For example, if your machine indicates 60% at 120 amps it means that for a ten minute cycle, your machine can be used at 120 amps for six minutes and the with the machine still turned on, allowed to cool for four minutes before welding is resumed. You can void your warranty of your machine if you don't comply with the duty cycle.

Originally Posted by Everlasted

You can void your warranty of your machine if you don't comply with the duty cycle.

I thought that welding machines would have a thermal or electronic protection in order to avoid this problem like it would switch off or reduce the output power.

It would be interesting to know.
Thanks.

Most new welding machines have thermal overload protection but you still need to be aware of the duty cycle. All the old transformer welding machines had no thermal overload and these machines could easily be used beyond the duty cycle. Obviously the warranty would not be a consideration as it would have run out long ago but these machines rely on the person carrying out the welding to be aware of the duty cycle.