Thread: Inverter mig welder

An interesting discussion was had today in our workshop
What is the advantage of an inverter mig against a transformer type
I asked people who sell both types and the answers I got were to say the least rubbish
Not one of them knew ,all they had were sound bites
* they are more reliable unlike the transformer type they do not fluctuate (anyone have this as a problem with there transformer welder)
* A smother arc
* less spatter
* you can stick weld with it (ok this one is fair enough but You can buy a separate stick welder for $350.00 and still be ahead)
* its the latest technology so its better
and my favourite *the arc is not as aggressive
I'm not knocking the Inverter more the sales people
I think the main advantages are light weight less power required
I am only talking about the lower end machines like the unimig 200 /250 and kemppi 180 etc and only the mig welders, the little stick/tig machines are great
not the top end pulse and programable types
I was wondering what sale pitch any of you have had and has anybody ever been given a solid gold reason why spend the extra few hundred dollars other than weight and size,
especially since some of them weigh over 35kg
So why would you buy a 200/250 amp inverter mig welder as against a transformer type if weight and power consumption is not an issue

Originally Posted by dubman

An interesting discussion was had today in our workshop
What is the advantage of an inverter mig against a transformer type
I asked people who sell both types and the answers I got were to say the least rubbish
Not one of them knew ,all they had were sound bites
* they are more reliable unlike the transformer type they do not fluctuate (anyone have this as a problem with there transformer welder)
* A smother arc
* less spatter
* you can stick weld with it (ok this one is fair enough but You can buy a separate stick welder for $350.00 and still be ahead)
* its the latest technology so its better
and my favourite *the arc is not as aggressive
I'm not knocking the Inverter more the sales people
I think the main advantages are light weight less power required
I am only talking about the lower end machines like the unimig 200 /250 and kemppi 180 etc and only the mig welders, the little stick/tig machines are great
not the top end pulse and programable types
I was wondering what sale pitch any of you have had and has anybody ever been given a solid gold reason why spend the extra few hundred dollars other than weight and size,
especially since some of them weigh over 35kg
So why would you buy a 200/250 amp inverter mig welder as against a transformer type if weight and power consumption is not an issue

I totally agree mate, the problem as it stands is that most welder sales people do not have the foggiest idea about welding and do not even understand basic fundamentals. They simply regurgitate what they were told at the last brainwashing session held by some company rep.
To answer your question, if weight and power consumption were not issues, I would probably not buy an inverter mig.
I own a high end transformer mig that is as yet undefeated by any other mig in it's amperage range as far as arc stability etc. goes.
I would pose the question as to how many of the super dooper new technology migs will still be soldiering on in 20 to 30 years time.
I am not bagging the inverters as such, but for goodness sake some of the sales pitches are beyond belief - as you have been astute enough to realise.
If portability is of great importance, then presumably you are on site, which suggests possible outdoor activities - why not use a stick welder and be done with it? In any case even if the power source is feather light, you still need a gas cylinder - going gasless - why not just use a stick welder?
No technology will make up for poor technique.

From an electronics/electrical perspective, inverters are a two edged sword.

On one hand you get rid of a big heavy and relatively inefficient transformer and replace it with a printed circuit board (or three) which are light and compact.

On the other hand, the power components of the inverter are often running close to their specification limits, and fall over when subjected to abnormal conditions, at considerable cost to the customer.

Many moons ago welding transformers were copper wound, more recently they have mostly been aluminium wound, with decreasing weight and cost, but a significant decrease in efficiency and duty cycle also compared to a copper wound unit.

At a workplace a few years ago we had three top brand single phase American 200A Inverter Tigs (abt $2500 each back then). If the machine factory behind us shut down one of their large machines, at least one and often two of the TIGS would go out, due to the power surge created. Cost was about $1200 per TIG to replace the high power card in the welders. At one stage we went through the entire stock of replacement and reconditioned cards in Oz in the space of 10 days, and the suppliers removed cards from new stock to keep us going. The issue was a $5 component rated at 400V that was normally subjected to about 380V, hit about 450 V on a surge and eventually died after multiple hits. We were supplied with a 3 phase 250A unit as a loaner, and it coped with the surges. The corresponding component in the 3 phase unit was rated at 800V due to the higher supply voltage. We eventually convinced to supplier to doctor the high power boards and install the higher voltage component into the single phase machine and the problem went away. The actual component cost was the same for the 800V and 400V versions.

I agree whole heartedly with the above and would add this as well.

Along with welding comes grinding and with that metallic dust.

This dust tracks across the circuit boards and eventually the board can go poof! and release the expensive blue smoke. Some boards in top quality machines are encapsulated in phenolic resin and can resist that treatment for longer.


If you suffer with a mud wasp problem these little bastids are fond of making a nest for hatching their young across the circuit boards tracks. It cost me $350 or so to experience this phenomena.

With a transformer mig I can't recall an internal electrical fault in one of them 45 years in the trade. The big copper wound Trans migs and the like have a electrical flux density not found in the inverters I have used. That's also why many of the aluminium strap wound transformers will never perform as well as their copper wound cousins.

Having said this I know someone will just have task about flux density.Well the quick and dirty answer is that its what effects the magnetic saturation of the iron core of the transformer. Think of it as electrical grunt. If there's any electrical engineers out there feel free to come in if I have made complete pigs ear out of the explanation jump in a rescue me please!.Its twenty years or so since I had to do this stuff and memory loss is creeping in.

Grahame

Originally Posted by Karl Robbers

To answer your question, if weight and power consumption were not issues, I would probably not buy an inverter mig.

If portability is of great importance, then presumably you are on site, which suggests possible outdoor activities - why not use a stick welder and be done with it? In any case even if the power source is feather light, you still need a gas cylinder - going gasless - why not just use a stick welder?
No technology will make up for poor technique.

Aren't most portable stick welders today inverter? Unless your going to buy a big Lincoln Generator/welder. So I don't see the difference? Inverter MIG, Inverter STICK.
Myself, What other reasons do you need to buy an inverter style welder; Low power consumption, Light weight? Sounds good to me!
I can chuck my Kemppi Mig in the back of my car in about 1 minute flat, and be on my way to a mates place, no 2 person lifts needed.
Can't stick weld aluminium either, if thats your site job.
Some are 10 amp plugs too, which is good when you don't have 15 amp at your disposal, no need for those Illegal adaptors.

Originally Posted by brenton21

Aren't most portable stick welders today inverter?
You are quite correct, the majotity of portable stick welders are inverter and very nice they are too. I would much rather carry an inverter stick welder than an inverter mig on site, particularly if you add in gas bottles etc.
Myself, What other reasons do you need to buy an inverter style welder; Low power consumption, Light weight? Sounds good to me!
Inverter migs definitely have a weight advantage, I don't see this as being as great a feature it is held up to be, but if others see it as a great feature that's fine by me. One reason I have for not choosing the inverter is the arc performance versus what I already have. I also question their longevity, (this also applies to inverter stick welders), compared to a transformer power source
I can chuck my Kemppi Mig in the back of my car in about 1 minute flat, and be on my way to a mates place, no 2 person lifts needed.
Can't stick weld aluminium either, if thats your site job.
You may like to check up on that. It is rarely done but is possible.
Further, if you are welding Aluminium, then you are using gas and the inverter mig just gave away at least part of it's perceived weight advantage due to needing to carry the gas cylinder as well.
Some are 10 amp plugs too, which is good when you don't have 15 amp at your disposal, no need for those Illegal adaptors.

True.
You are obviously happy with your inverter mig and that is great. There are many differing types of power source available for diverse applications. I guess my likes/requirements in a mig are different to yours. My welders all work hard,for this reason I prefer a more workmanlike industrial set up and would gladly trade some weight for grunt and staying power.

Originally Posted by dubman

An interesting discussion was had today in our workshop
What is the advantage of an inverter mig against a transformer type
I asked people who sell both types and the answers I got were to say the least rubbish
Not one of them knew ,all they had were sound bites
* they are more reliable unlike the transformer type they do not fluctuate (anyone have this as a problem with there transformer welder)
* A smother arc
* less spatter
* you can stick weld with it (ok this one is fair enough but You can buy a separate stick welder for $350.00 and still be ahead)
* its the latest technology so its better
and my favourite *the arc is not as aggressive
I'm not knocking the Inverter more the sales people
I think the main advantages are light weight less power required
I am only talking about the lower end machines like the unimig 200 /250 and kemppi 180 etc and only the mig welders, the little stick/tig machines are great
not the top end pulse and programable types
I was wondering what sale pitch any of you have had and has anybody ever been given a solid gold reason why spend the extra few hundred dollars other than weight and size,
especially since some of them weigh over 35kg
So why would you buy a 200/250 amp inverter mig welder as against a transformer type if weight and power consumption is not an issue

Hi Dubman,

I wrote a long post 3 1/2 years ago about the inverter machines, link is here INVERTER WELDERS . Feel welcome to call me on 1300 881 991 and we can have a long discussion about the your question. No sales pitch, just the facts. I too get irritated by morons selling inverters and talking total crap with no idea about what actually goes on under the cover. I design them and I fix them so I can tell you the ins and outs.

Regards
Pete