MIG and AC TIG welder, combined or separate units?

[Core]

I want to do both AC TIG and MIG/MAG welding, for both steel and aluminium alloys. I have 230V 50Hz mains, and access to 3-phase if needed. Location Hong Kong for this/these units, hence sourcing from China would be obvious.

Would it be advisable to get separate machines, or will a combined machine do?

Items that matter (obviously) are

- Weight/size for portability
- Requirement for 3-phase (separate units might mean one of them could be single phase?)
- Quality/durability ... these new machines with inverters won't last as long as transformer units, right? The cost of low weight/size? Will separate units mean they last longer?

I won't likely need to do TIG and MIG/MAG weld on the same day, but obviously, storage space required would be affected if having two units. But if two separate units means they are each more portable, then that would be a plus for sure.

Awesome community here. I have already read a lot of the guides and taken notes, but still unsure about AC TIG and MIG/MAG combined or separate unit(s)

Thank you

 

[Core]

Adding to the above, if such a unit, or two units, could include a plasma cutter, that would also be ab added plus.

Again, thank you for having such an awesome community here. I will not be working on cars, but rather on building structures (aluminimum beams and casings), as well as casings and shielding for various solar thermal panels prototypes and such.

 

[tom2207]

I buy separate machines ,, if one breaks all your abilities are not lost , you still have options.

 

[Core]

I buy separate machines ,, if one breaks all your abilities are not lost , you still have options.

That does make a lot of sense as well. I like redundancy (except if redundancy meant ... I was made redundant).

AC TIG 350A, MIG/MAG 200A, does that make sense? Or can I dial down the MIG/MAG enough to run on 230V/13A? That should be only 150A on MIG/MAG, where does that leave my options with regard to material thickness for steel? If I had to have two machines anyway, it would be great if one was single phase.

 

[zzr1200]

Also if you have easy access to 3ph, possibly 2nd hand industrial units maybe be cheaper to purchase than new 1ph units especially if your after 300+ amps for a tig welder. A while ago I purchased a Miller Maxstar 350amp dc tig including water cooler (used for 1200hrs)
for £500.00 from Ebay. Absolute bargain....

 

[addjunkie]

Separates every time

 

[Pigeon_Droppings2]

+1 for separates...when I'm out and fixing a gate... I don't want yo be using my mig or tig!

 

[Core]

+1 for separates...when I'm out and fixing a gate... I don't want yo be using my mig or tig!

What will you be using, stick? Oxygen-Acetylene?

 

[Core]

Thank you for your answers very useful. Consensus seems strong towards separate units. Weight will be an issue, so I will most likely pursue inverter based units for both.

 

[Pigeon_Droppings2]

What will you be using, stick?

Yup I have a small cheap stick welder that I don't mind leaving lying about. Cheap, light and if it goes missing I don't mind

 

[eddie49]

A few random comments:
- sourcing welders in HK probably means inverters only. I guess they will be very cheap from China, and in such a dynamic place, very few transformer-based machines left
- low-end inverters are not as reliable as transformers, but they are small, light, and cheap
- MIG needs a Constant-Voltage ( CV ) source, Arc/MMA/TIG needs Constant-Current ( CC ). An inverter can do both, just by using different feedback ( output voltage measurement vs. current sensor shunt ) to control the Pulse-Width Modulator that drives the IGBTs
- single-phase AC mains in HK used to be wired for BS1363 British 13A plugs, maybe it still is in older buildings?
- reckon with 30 to 40A per millimetre or 1A per thousandth of an inch of steel thickness
- a typical 160A DIY MIG/MMA inverter will weld 5mm on MIG off a 13A plug
- for thicker material, switch the inverter to MMA mode and use 2.5 or 3.2mm arc rods between 50 and 140A
- small MIG/MMA inverters offer scratch-start or Lift TIG when set to CC ( i.e. MMA ) mode, but for real TIG work you need HF start, and for aluminium you need AC/DC, which means buying a "real" TIG welder.

 

[Core]

A few random comments:
- sourcing welders in HK probably means inverters only. I guess they will be very cheap from China, and in such a dynamic place, very few transformer-based machines left
- low-end inverters are not as reliable as transformers, but they are small, light, and cheap
- MIG needs a Constant-Voltage ( CV ) source, Arc/MMA/TIG needs Constant-Current ( CC ). An inverter can do both, just by using different feedback ( output voltage measurement vs. current sensor shunt ) to control the Pulse-Width Modulator that drives the IGBTs
- single-phase AC mains in HK used to be wired for BS1363 British 13A plugs, maybe it still is in older buildings?
- reckon with 30 to 40A per millimetre or 1A per thousandth of an inch of steel thickness
- a typical 160A DIY MIG/MMA inverter will weld 5mm on MIG off a 13A plug
- for thicker material, switch the inverter to MMA mode and use 2.5 or 3.2mm arc rods between 50 and 140A
- small MIG/MMA inverters offer scratch-start or Lift TIG when set to CC ( i.e. MMA ) mode, but for real TIG work you need HF start, and for aluminium you need AC/DC, which means buying a "real" TIG welder.

Thank you so much, Eddie.


Yes there is BS1363 here, but I have 3 phase 220V 32A, so up to 22kW if I had ever needed that. In Hong Kong, most water heaters are around 20kW, of the instant flow, tankless types.

I have found a MIG/MMA which even has TIG also, but only DC. I should have it some time next week.

For a TIG welder, I am still looking. Looked at a 300A A/C TIG version of the brand SPARK, but I was suggested by a friend to have at least 350A to be able to do aluminium up to 8mm. It does not have to be the most pretty looking welds but for those welds of thicker aluminium, they will have to be sturdy. I have seen some using a blow torch to preheat thicker aluminium and then get away with less amp than should have been possible.

Most aluminium I will weld will be less than 8mm, but I don't want to have to get a larger machine later on.

I wish I could just do steel with MIG but most of what I do will be outside equipment where the climate is wet and salty air (5 minutes from the beach here ...). I have seen it is possible to do aluminium with MIG, or even using those soldiering style methods, but the latter look more like glue than welding, and MIG on aluminium seems to be the hardest to succeed with (as what I read in the guides here on this awesome website).

Thank you, again, those who answered.

 

[Core]

I have an old stick welder, btw, made in Korea. It is an OWD-200 OTTO 200 IGBT inverter DCARC welder. The specs say 220V AC, 7.5 kVA, 50/60 Hz, load voltage 28 V. Output current max 200 A, duty cycle 40%. There is a 1-10 AMP selector, as well as a switch to choose either HOT START or NORMAL.

I got it for free, but haven't used it yet. The plug looks like a European plug mains plug, but it looks slightly smaller and it says 15A 250V on it, as well as DONG YANG. 2 pin but with recessed ground on opposite sides. The cable is about 13mm thick and is labeled 3 core 3.5 mm2. How can this welder say 7.5kVA when the plug says 15A 250V? What power factor are they using, 0.5??? Because the welder itself only says 7.5kVA, while only the plug specifies the 15A.

I found a website from Sun Kwang Engineering where they have this welder, but with no further information than I already have. I also found a manual online for it, but only in Turkish.

Anyone familiar with this welder, and can someone explain how a 7.5kVA welder can be fitted with a 15A 250V single phase plug?

 

[Core]

For TIG, I got this 315A TIG/MMA welder from Riland. It is what the local welding pusher happened to offer, so I took it. I am in Hong Kong, and the panel is in Chinese, but I have an English manual AND I found the exact panel in a video online, and grabbed this picture from it.

The switch to the left that says OFF and ON actually means PANEL and REMOTE (pedal). The pedal I got has to potentiometers also, a MAX and a MIN. As far as I know, if the left switch is set to ON (remote), the MAX and MIN on the pedal will override the panel setting. Or at least some of the settings? The manual is very unclear, poorly translated from Chinese to English and 80% of the manual is warnings and cautions, the majority of them obvious.

I have set up everything so the machine works. I have a good 3-phase power supply, and I also got a water cooler. I have stopped testing for today, but I never managed to find a setting that produced even reasonable results. I am a bit in doubt about the remote function of the pedal, vs the panel. Also the peak vs base current setting. The display only shows changes to the base current, or the actual current, while the machine is running. This means that many of the settings I do are kind of swagged. MF frequency, 15 to 450, where on the scale is 90 or 120 Hz? I have considered using a tone generator to literally set the frequency by ear. I am a bit disappointed that the display won't show other settings than base current.

I have seen other machines that are more or less copies of each other, all looking like this on down to switch and potentiometer positioning. I hope someone here has a similar machine and can lead me into a setting (using the foot pedal ideally) I can use as reference.

I am testing on 2mm aluminium sheets. I do not yet have a welding table, so there is no good heat sink and the object becomes quite hot, quite fast.

I have read numerous posts, including the sticky one on this website. Seen dozens of aluminium TIG welding videos, but on my first day of testing, I did not get too far with regard to results.

Thank you for any feedback.

 

[Core]

On a different note, I got a MIG/MAG machine also, only 200A and much smaller than this one. In Hongkong, it is a huge problem to get CO2 gas, especially of welding quality. One needs to have some kind of licence or permission, so I am considering alternatives. The local bar has hinted I might be able to get some CO2 from their beer/soda CO2 bottles, but I don't have a bottle to have it in, and I don't know if that CO2 for tap soda water will work for MAG welding.
Ideally, if I could find a solution so I could make my own soda water here, it would be a plus. I am not so sure about the purity and quality of CO2 for welding and for soda machines (can one be used for the other, either way?)