Inverter welders

use a battery.

I don't do much welding but switched from a substantial old-school MIG welder to an inverter type and it's been a revelation. So much easier, better welds, smaller, lighter. I bought mine from R-Tech, but there are many cheaper ones around.

Arc/Stick/MMA or Wire fed (MIG/MAG)?

Not sure if my experience is typical, but many years ago I bought a SIP Merlin 150A arc welder, and used it occasionally over the years for repairs mainly, and the occasional bit of fabrication.

I found it a PITA to use because it had a very poor duty cycle - you might get 10 mins "welding" out of it before it would thermal trip, and then you would have to wait 20 to 30 mins to have another go. It made any job frustrating and time consuming. In fact just being switched on was enough to get it to overheat! I improved this by adding a couple of big fans in the case (making it a "turbo" welder!) It was a little better but still crap.

(if anyone local wants a 150A Merlin - good condition - hardly used - you can collect it for free!)

Then a couple of years ago I bought a decent inverter mig welder, as my daughter needed to finish her engineering fabrication project during lockdown and could not go to the college workshop, and that seemed like a good enough excuse :-)

I have to say it has been a revelation. Even using it for arc/stick welding it is *so* much better than the old AC "buzz box" - much easier to strike and maintain an arc, much smoother welding.

I find mig is also much faster and easier in many cases - especially if you need to weld thinner stuff. (I can successfully do 0.8mm steel sheet with it by dropping to 0.6mm wire). Duty cycle is a non issue - I have never yet tripped it.

As a result I actually enjoy using it and am happy to tackle projects[1] rather than just repairs that must me done. I have not done vast amounts with it (still on the first 5kg of wire and the second bottle of gas)

I don't have any recommendations in that price range - not because there are not decent welders to be had - just I have not tried one. The very small box inverter arc welders can be had for spare change almost. A mig setup a bit more. Gasless (i.e. flux core wire) are fairly cheap - although don't weld as nicely - and create a bit more spatter. You can weld outside in the wind with flux core though.

Most in the sub 1k price range come from the China - but going with a good UK based dealer should mean you have spares and support available.

I went with:

(if you search youtube for the channel doubleboost he does some good reviews of the R-Tech kit)

I would expect you could get plenty of useful work out of a less powerful setup - I often use it on a 13A supply which limits the maximum current you can weld with to a bit under the full 180A, and I have never had a problem.

That has been my experience too, I bought my inverter welder a couple of years ago.

Ooh, I just looked, I bought it almost 6 years ago in 2017! It's a 'Parweld XTS 142 MMA', it cost £157 back then and has served me well.

I have a big old oil cooled Oxford built in '73 which goes up to 320A and will run all day without a break and produce commercial quality welds in anything up to half inch plate. But it does weigh a ton! More recently I acquired a Rohm MIG inverter welder rated at 200A for thinner guage metal. I took the current rating of this with a pinch of salt, expecting to only use it for car bodies at half that current. However, I have to say I've been mightily impressed and use it more and more for the heavier stuff. It also does stick/arc welding and amazingly I can get commercial quality welds up to 10mm plate with no drama and so far at any rate, not a single 'breather' for the duty cycle problem one often gets with these type of welders. So I can certainly recommend them and the price is very reasonable indeed, all things considered.

I far prefer an old 50Hz MIG to an invertor stick job. YMMV of course. If you're only going to buy one machine for occasional use, make it a MIG. If you have to economise, old lumps like SIPs are cheap & annoyingly heavy.

Are you saying you do want more than your current one (no pun intended) can cope with, or is it just you want a shiny new one to play with? Brian

So, what is the basic difference from the way it works. To me from my old school days, when I could see, you are basically heating stuff up and using the welding rod to basically brace it as you want it to be. Not my favourite thing in metalwork, I liked soldering and forming nice shapes in sheet myself. grin. Brian

Brian Gaff snipped-for-privacy@gmail.com wrote

Much easier to use, much better on the thinner metal, much lighter to move around, no low duty cycle.

A decent gasless MIG etc allows that too.

While you can't see them anymore, some of the videos show how much better the multifuntion welders actuall are.

You mean between a traditional transformer based welder and an inverter?

Transformer based units are welding with 50Hz AC - so there are zero crossings at a relatively low frequency - so harder to start and sustain an arc. The regulation of current/voltage output is also fairly crude.

So for a constant voltage processes like MIG where the weld current will be dictated by the wire size, the feed rate, and the torch position the power supply needs to react quickly to changing conditions to get a good quality weld.

Inverter ones by default are DC - so smoother striking and welding. Posher ones can also do AC, but with far more finesses than you get from a transformer - so you can vary the waveform duty cycle and frequency. This is important for welding Ali and other metals where you need the reverse polarity of the waveform to provide a "cleaning" action that penetrates the oxide layer that rapidly forms on the metal.

High end inverter setups also allow for "pulse" welding - alternating between higher and lower current outputs - for better puddle control on difficult welds.

The in MIG and MMA the electrode is both sustaining the arc to fuse the metal, and also providing the filler. Most welds will need some kind of filler to make a strong joint.

In processes like TIG, then there are some occasions where you can make a pure fusion weld on a fitting joint. It can work well for outside corners on thin plate for example.

Indeed, basically hot glue for metal, but that's done in different ways. If we stick (no pun intended) to electric arc welding then you can supply the heating current through a regular transformer at mains frequency, or using semiconductors that rectify and switch the incoming AC mains in the same way as a switched-mode PSU; this uses a smaller transformer at higher frequency and efficiency, so it's typically lighter and more compact with better duty cycle than a traditional transformer machine. It also allows fine automatic control of the output current leading to a more stable arc, and may also support multi-mode processes so one machine can handle MIG, AC/DC TIG and stick welding. Also the increasing cost of copper and the decreasing cost of IGBT as the technology has matured favours inverter machines.

TLDR: Inverter welder is more luggable, better arc control but a buzz box is likely to survive longer esp. in harsh conditions because it's so simple.

I have "an old 50Hz MIG" as well as the inverter one, it's better for thin metal but I prefer the inverter for everything else.

Age & quality are also fairly big factors. An old Sip or Oxford should be reliable, a new invertor thing is to often chinesium junk.

That is a major consideration, in fact. The complexity of some of these newer inverter welders renders them less reliable overall than the old traditional Oxfords and Olympic oil-cooled transformer types which just soldier on and on over decades without issue. My 320 amp oil-cooled jobbie will be 50 years old this year and still functions like the day it was made. Will we be able to say the same for even the best inverter types produced today? Nope!

But its worth getting a modern one because it works much better and it doesnt really matter if it lasts 50 years given how old we are, even Adam who is one of the youngest.

Yesp! Modern, very complex, cars are *way* more reliable than those of decades ago. Well designed electronics is amazingly reliable. I guess the underlying reason is that computers need 'amazingly reliable' electronics to be at all viable and we really do have a lot of computers that 'just work'.

Modern welders are mostly at the junk end of the scale, made from scrap parts pushd beyond their specs. Never mind whether they'll be around in 50 years, wonder iif they'll be here in 5 or 10.

As for invertors being better in other ways, 50Hz works pretty well IME. If you're an occasional user I can't see invertors' upsides outweighing their early demise.

As if often the case, to an extent you get what you pay for. Buy a decent inverter and it will last years, a budget one perhaps less.

I could not agree less :-) Having had the basic transformer welder for decades, recently switched to an inverter, there is no way I would go back to the transformer - especially because I am not doing it intensively. I have less hands on time to build a high skill level, and the modern welder just gets better results with less hassle.

If you transformer welder was serious pro level machine when it was new, then sure it might fair better, but at the "less than a grand" price point, going inverter is the obvious choice.

Old cars are far easier to keep going than new. Perhaps the greatest leap forward in reliability was electronic ignition. Everything else has complicated thing to the point that some faults are near impossible to repair, especially some intermittent issues.

The last car I know that was written off from a repair POV was due to a faulty ECU. Even electronics ICs are designed to last a number of years. By way of example, tracks are sized in ICs according to potential electromigration failure.