[HelpMeNotKillMePlz]

I plan on using a 100A gasless mig welder to work on 2 - 3mm thick galvanized steel pipe and similar thickness sheet steel. I've read that 30A / mm thickness is a rough guide to a welder's potential. Is this accurate? Should I expect less performance given it is gasless?

This is the welder I plan on using.
https://www.bunnings.com.au/bossweld-10 ... r_p6380043

An example of a pipe I will likely use for my project
https://www.bunnings.com.au/kinetic-15- ... e_p4700246

The next model up is a 150A model however it requires a 15A plug (which I don't have access to) and it's too expensive anyway.

( I am aware of the dangers / challenges of welding galvanised. Have my milk ready, welding will be done outdoors, will grind off as much galvanic coating as possible before working on it. Looking into respirators etc. Any other tips happily accepted however!)

Thanks!

[WeldingJunkie]

I don't think you'll get enough out of your duty cycle to weld 3mm with a 100amp gas less welder

[Demented]

I don't think you'll get enough out of your duty cycle to weld 3mm with a 100amp gas less welder

Small bits at a time. 20% duty cycle at 100A. For just hobby stuff it would work, but not ideal.

While you're looking up respirators, check out 3M 2297 filters. They're rated for galvanize fumes as well as ozone. I can go all day welding over galvanize stuff with those filters and never once smell or taste anything bad.

[WeldingJunkie]

Demented 3mm is almost 1/8" (10) gauge you need min 135-150 amps, no way that is going very hard IMO to do the job unless you are making multiple passes, good luck with that especially with gasses. Id look at a different welder or borrow one. 20% duty on top of it, that might be a recipe for a long long day or week. Just my 2 cents.

[tweake]

don't waste money on those gutless welders.
bossweld make some 140 amp inverter arc welders that work off 10a outlets.
that would work perfectly fine and by memory its cheaper than the mig. (bunnings sell them here at $250nz).

frankly for the cheap welders i would go stick welder over a mig every time.

[cj737]

Demented 3mm is almost 1/8" (10) gauge you need min 135-150 amps, no way that is going very hard IMO to do the job unless you are making multiple passes, good luck with that especially with gasses. Id look at a different welder or borrow one. 20% duty on top of it, that might be a recipe for a long long day or week. Just my 2 cents.

A 100 amps might be on the cool side, but with flux core wire and sheet metal, you sur as fcuk won’t need 135-150 amps.

I’d side with Tweake though on a different machine...

[WeldingJunkie]

I agree with Tweake as well but not everyone can stick sheets with rods. Also my point was you cant gasless weld 1/8" with 100amps period. not a little cold not at all.

This is from Weldingtips and Tricks links to Miller for Flux core wire. Explain to me why you 'you sur as fcuk won’t need 135-150 amps"

What happens if this guy goes out and buys the machines based off what you said and it doesn't work. Cant take it back and get another machine and say um im sorry i got the wrong one.

How many amps do you think you would need for 3Mil? you wouldn't get a high enough wire speed either with 100 amp machines.

[tweake]

3mm is not what i would call thin. have done far thinner thin wall tubing with stick.

the simple problem with low powered welders is tomorrow you want to weld something thicker and especially newbies will give it a go and end up with problems. then end up buying another welder.

stick welder because its good to learn with and you get a better machine for the money.
you can do substantially more with it than a low powered mig.

[Poland308]

Bumping up to a machine capable of 150 amps would be a good option.