Welding Tips and Tricks

I bought a portable 90a wire welder. I need to know the safety practices on using one. The instructions say do not use outdoors. That is where I intended to use the welder. The instructions said lay on a rubber mat or piece of thick plywood to keep from getting shocked. What I intended to do was assemble the exhaust system on my car from after the resonator on back and then tack weld and remove the exhaust and then permanently weld. So what should I do. can I weld on grass?

Ha.

Must be in California. Can't do anything.

Put it on the ground, outside, and weld away.

Hello la1,

If you purchased the welder from Horrible Fright the biggest safety step you can take is to return it! These welders tend to have the contact tip (where the wire emerges) energized at all times. It SHOULD be energized only when the trigger is depressed and wire being fed out. That said, here are a few links to safety information:

http://www.aws.org/standards/page/safet ... act-sheets

http://www.lincolnelectric.com/en-us/ed ... afety.aspx

https://www.osha.gov/SLTC/weldingcuttingbrazing/

As to not using it outdoors... I guess the manufactured is afraid the unit may get a sun burn. I suspect that the unit is a flux core welder - no shielding gas involved. If that it the case, the flux core process is appropriate outdoors use. Gas shielded wire (MIG) is a concern outdoors if there is wind which can blow the shielding gas away. I would not use the welder in the rain and be sure to use a GFI protected electrical outlet to plug it into.

Ken

I don't know how gfi's work in the usa but here in oz it works with the house connected earth circuit. If you are outside on the ground you are separated from the house circuit and have become a human earth spike. In this case your gfi won't protect you. Maybe this is why the manufacturer, knowing the contact tip is always live, says not to work outside.
Otto is a usa electrical wiz and will verify this when he reads it.

Coldman wrote:I don't know how gfi's work in the usa but here in oz it works with the house connected earth circuit. If you are outside on the ground you are separated from the house circuit and have become a human earth spike. In this case your gfi won't protect you. Maybe this is why the manufacturer, knowing the contact tip is always live, says not to work outside.
Otto is a usa electrical wiz and will verify this when he reads it.

That is interesting?? In the US the earth is for fault current, Our GFCI's look at balanced current, if not balanced it is going (leaking) somewhere and the trip/open circuitry is employed.

FYI, Our GFCI's will work per design without a "ground" wire and I do not agreed with in the event you would lose the neutral.

> Lay on rubber or plywood
> Do not use outdoors

I'm wondering if these are overly-protective product labels that seek to avoid lawsuits. Kinda like the labels on a jar of peanuts: "Warning: Contains peanuts."

As mentioned, if you're using gas shielded MIG, a light breeze can blow your shielding gas away from the weld, and create contamination. The deal about laying on a piece of rubber or plywood is to prevent you from getting electrocuted, and the way to prevent that is to stay out of the electrical circuit: if you are touching an electrified surface and then you touch a grounded surface, you'll get zapped if that is the circuit's path of least resistance. Know your process, and keep in mind some basic facts about electricity, and you'll be ok.

What kind of welder do you have? And welcome to the forum, BTW.

>Can I weld on grass

The MIG process, gas or self shielded, gives off sparks, and sparks can cause fires. This is a common-sense question that only you can answer: if it's grass in your yard that you mowed and it's low, and it rained this week so it's not dry as tinder, then your answer may be yes, weld away. The answer is different if you're standing in a hay field or in a scrub with grass up to your knees. I recently stomped out a fire in low grass in a residential setting, so anything is possible. If you have to weld over grass, have someone stand fire watch.

Serious answer - your looking at 18 > 20 volts most likely maximum out of a 90amp mig - this has come through a transformer so is isolated from the mains - I don't see how you would have a problem from an electrical point of view if used outdoors unless you place the entire welder in a pond or something creative !- seems like safety Nazis & insurance claim avoidance is the main thing here - I'd say just get on with it but setting fire to long dry grass is a valid consideration - just use common sense !

Tempted to answer I know many people that weld on grass - some that weld way better on grass & some that need a drink - just try not to set fire to the car because however good the weld might be that would be a " CF "

monte_santa_cruz wrote:Ha.

Must be in California. Can't do anything.

Put it on the ground, outside, and weld away.

LOL!

I doubt Cali has anything to do with it... Poorly translated Chinese technical data and manuals likely are.

I agree, put it on dry ground, cover your work area with some plywood or paneling to protect dry grass, and go for it.

DLewis is right, a GFCI will work without earthing, detecting milliamp differences in "hot" versus "neutral" current, but in U.S. codes, modern homes have the neutral bonded to earth at the service entrance. I've even had an issue with a GFCI circuit 200' from the main service because the neutral was in contact with the ground, leaking probably microamps.

The comments about these budget welders always being "hot" at the tip is true, and if you are a ground path, you can get "bit", but at under 50V, you are at almost no risk of harm unless you're laying in a puddle.

Steve S

As to not using it outdoors... I guess the manufactured is afraid the unit may get a sun burn

I suspect that the unit is a flux core welder - no shielding gas involved

yes that is correct

be sure to use a GFI protected electrical outlet to plug it into

will do

Our GFCI's look at balanced current, if not balanced it is going (leaking) somewhere and the trip/open circuitry is employed.

yeah that is the way that I thought GFI's work as long as the current flowing into the circuit matches what is flowing out , if there is an imbalance the GFI will trip.

What kind of welder do you have? And welcome to the forum, BTW

its a 90amp Harbor Freight wire welder. Thank you I am sure I will learn a lot here.

If you have to weld over grass, have someone stand fire watch.

was mostly concerned about getting shocked .

If you purchased the welder from Horrible Fright

LOL I like Harbor Freight tools AND the 90a welder I have has almost 1000 good reviews with a lot being 5 stars. Could it be you are a tool tyrant

DLewis is right, a GFCI will work without earthing, detecting milliamp differences in "hot" versus "neutral" current, but in U.S. codes, modern homes have the neutral bonded to earth at the service entrance. I've even had an issue with a GFCI circuit 200' from the main service because the neutral was in contact with the ground, leaking probably microamps.

so are all the Neutrals connected together and out to the power pole ...they are the return path for the current? ...and the ground is for safety in case the neutral is open ?

The comments about these budget welders always being "hot" at the tip is true, and if you are a ground path, you can get "bit", but at under 50V, you are at almost no risk of harm unless you're laying in a puddle.

so what happens if welding on my car for instance and I brush up against the car. With the TIP only having 50volts, its the current that kills. I think I saw where it said not to touch the tip to the work...it did not say what would happen, also there is a duty cycle where I weld for 2 minutes then let the welder rest, if I used a bigger fan would that reduce the time of rest for the welding unit.

No tool tyrants here. The Harbor Freight 90amp gasless wire welder had a HUGE design flaw. Its output is a/c, wire welding processes require d/C. As delivered that unit is broken. Google flux core welding polarity. Also seach youtube for instructions to convert your welder to direct current, not so much that you want to do it just to get a better understanding of the problem

I don't think your welder will let you weld when it hits the duty cycle wall but being an HF it might. A bigger fan won't do anything because the welder is trying to cool down its internals with the on-board fan so you can blow air on it all day and it's not going to help. IF IT DOES not shut down automatically when it gets hot and you don't have any clue its getting hot and you keep going, you will be taking it back to HF for a replacement. Good luck and report back your results.

If you are looking for knowledge in regard to the electrical safety aspect. Google a guy named Mike Holt, he has made a career out of grounding and bonding.

+1 for Mike Holt

http://www.mikeholt.com/free-resources.php

Mike is a sharp and knowledgeable guy. He has one video out though where he is using a 120V suicide cord, CT and Ohms Law to try and get his ground field down to less than 25 ohms that made me go uhhhhhhh hmmmmm.....lol

Also seach youtube for instructions to convert your welder to direct current, not so much that you want to do it just to get a better understanding of the problem

yeah I saw that on you tube where they use a 100amp bridge rectifier and a capacitor.

I don't think your welder will let you weld when it hits the duty cycle wall

in the instructions it says something about letting it cool after welding for 2 minutes ( or some time period) . sure is strange HFT haS over 1000 reviews of people that purchased the 90A Wire welder and they are all almost 4 stars out of 5

Dlewis and ldbtx wow that guy does know his stuff I watched the ARC Flash Hazard warning

He has one video out though where he is using a 120V suicide cord

whats a suicide chord? and which video is it

It's the equivalent to jumper cables that you hook to a hot 220 volt leg and use a ground as your common to run a 110 volt tool.

You point out a valid concern about the hot tip touching the car body.
If your earth is on the exhaust system when you weld it, all should be good.

Nitpicky bit: It's actually a RETURN lead, not an earth lead. It completes the circuit on the secondary side of the transformer to the electrode (wire).

If the tip touches the car body, you run the risk of the circuit being completed through other areas of the car and doing something not very nice to your car's electronic bits. It's a bit like touching the missus where you shouldn't when she's not in a good mood. Something bad could happen.

If it is high risk what you're doing, you should disconnect your battery leads.

Our houses here in Oz use a MEN system or Multiple Earth Neutral. The neutral wires are terminated to a bus bar and an earth lead is joined to the bus bar as well.