Thread: Current set up for your Mig

Grahame, certainly no foot in mouth disease. I always find your comments helpful to readers, informative and well educated. The Telwin brand you mentioned is also sold here in Aust as other "known" brands. To give you an idea about Italian machines, our company used to sell quite a few Esab Caddy 130/140 DC Inverters. Eventually Esab dropped the 130 from its range and only sold the 140. These machines were made in Sweden and started out with 2 years warranty (parts & labour) which was increased to 3 years. Esab had trouble competing on price with the cheaper Italian imports so they decided to get some "made" (rebadged) in Italy by Selco (which are also sold out here under that name and some other "known" brands), they were rated at 150 amps.To give you an idea, the Caddy 140 sold at a discounted price of about $1700.00 complete with tig torch,MMA leads and Reg, the Caddy 150 sold for about $1150 complete, the 150 only had 12 months warranty. The most stupid thing Esab could have done was put their name on it because the Caddy was the industry standard, the benchmark and all of a sudden people are saying "hey I can buy a genuine Caddy now 150 amps for less than a 140. The 140 was also generator compatible and the 150 wasn't. The 150's started dropping like flies, I know of repair agents who had quantities of 30 and 40 in for repair but in fairness to Esab they were selling them at competitive pricing and there were just as many other Italian brands in getting repaired. The end result was that not only did it affect the Caddy 150 sales for Esab, it also had a negative affect on their 140 sales and although the 140 is no longer in production, sales of their current range have never recovered. The same goes for a plasma Esab used to market which was made by one of their subsiduary companies in the USA (L-Tec). The 240 volt machine was THE best 240v plasma on the market (I say that confidently) and because they couldn't compete on price with the Italian equipment they dropped the US model and imported a substitute from Italy. Admittedly it was cheaper but the warranty repairs started flooding through the door, (We sold probably 100 or more US built machines over a period of years with not one warranty claim). Sure you can have problems with better quality machines also and I have had, I also don't hide the fact from the customer but what I can assure them is if they have a problem it will be fixed immediately and wont be re-occurring. You'd probably be surprised who makes what for whom these days or where the country of origin for some of this equipment is. Some people do get a good run out of the Italian machines but it is usually in low usage/light duty applications but I have seen people who have worked the odd one quite hard and had a good run. With the amount of them sold (and people think they must be good because there are lots of them out there but it's only because they're cheap) the law of averages says that some lucky bugger will get a good run out of theirs. If a tradesman pulled up to my house to do work and he was using an Italian machine, I'd think, now here's a bloke who is not serious about his work. It would be like seeing a bloke on a big steel fabrication job with a GMC drill.
I know it's horses for courses but people are so naive. SIP market a range of light duty welding machines painted in silver, they also sell exactly the same machines in a maroon colour under the name Merlin, well Merlin must really be waving the old wand inside there because somewhere in that maroon paint, they are able to find another 5-10 amps. eg an SIP 150 is sold as a Merlin 160, you should have seen the rep trying to explain that to us one day, one of the worst jokes I've heard but we all had a good laugh.
Do people really think a Ryobi 100 has 100 Amps, have they ever welded with a true 100 amps ? I could tell a hundred similar stories but I don't want to bore people to death. Sorry to rave on but I get passionate about quality.
All the best
Regards
Bez

G'day All.
I understand about getting what you pay for.
If I were to be welding a large amount, I would be buying the best gear that I could.
But, being a weekend p1ss around welder, I have to buy gear that meets the approval of my financial controller .

The Transmig 165 does all I want from a mig welder.
Any larger welding jobs get taken to work and done by the fitters on the bloody huge WIA mig they have over there in the workshop.

For a cheap welder, the 165 is great. It is 2 years old and I can't fault it.

Firstly to Barry excellent piece, thanks.

I'm a fan of migs, mainly because a punter like me can produce a half decent weld, with little skill.

Bez

I agree with the comment that many people who have a cheap Italian machine think its great.

However, have they ever used a better machine?

I am no expert in welding by any stretch; but was taught at tafe using three phase MIGs, which were excellent; easy to use and producing excellent welds.

I do not own a MIG; but have borrowed friends’ MIGs over the years; including SIP, Unimig; and a couple of other brands, all of which did the job, just.

All of them I had problems setting the right voltage [few voltage steps] one I had to get repaired; on another the tip of the gun melted [I was using argonshield which apparently is hotter than CO2].

I was not welding anything outside the specs of any machine, very simple jobs.

I also find when using a MIG that the job is not just 10mins, but could be over a whole day, something these cheaper machines are not designed for but is not totally uncommon for a weekend warrior.

I would like to own a MIG however the ones I can afford are not worth it; One day I would like to add a decent mig to my tool kit.

One other point, do all 240v MIGs have the ability to be gas and Gasless?

Something that is always advertised, which I just assume all can do anyway.

One other question, apart from weight, what is the difference between copper and aluminium transformers? A sales person informed me, nothing except aluminium was cheaper.

Thanks

Pulpo

Pulpo
Please take this as an way of helping every one not a criticism


“ on another the tip of the gun melted [I was using argonshield which apparently is hotter than CO2”]

Sorry mate ,but that is completely incorrect
Argoshield (there’s a few grades of it ) is BOC,s proprietary brand of shielding gas. It is a mixture of Argon gas,Oxygen and Co2 the percentages are dependant on which grade is chosen. Argon is the major % is in all of them. Argon is an inert gas ( meaning it has no reaction with the metal or atmosphere) . In fact the very reason Oxygen and Co2 are mixed with argon is to gain some reactivity (read penetration) Each grade of argon has different effect upon the weld bead profile.

Co2 is the gas used in heavy duty application where the welding is completed in a downhand (read flat ) position.Co2 (Carbon dioxide ) reacts with arc giving it a very deep penetration. By comparison with Argon, Co2 could be termed, hot.

The reason that the contact tip was welded to the wire is that the wire speed was not quick enough to match the burnoff (the voltage setting ).This was that hot that the arc burn’t back up the wire and fused with the copper.Who says you can’t weld copper to steel.

[One other point, do all 240v MIGs have the ability to be gas and Gasless]
No some migs such as the WIAThe wire polarity can be swapped back and forth.Others are fixed. Polarity is electrode +(positive for Flux core-gasless) and eEectrode - (negative for gas cover)




[, what is the difference between copper and aluminium transformers? A sales person informed me, nothing except aluminium was cheaper.]

Easy, the copper has a greater magnetic flux ( the amount of magnetic affect that transfers current across your transformer windings )
Think about towing a caravan with a car.

Car with four cylinders— aluminium coil
Car with V8 or diesel - copper coil
Car with turbo motor – inverter welder
Its about the easiest comparison I can think of at the moment.


Hope this helps

Grahame

Originally Posted by Grahame Collins

Pulpo
Please take this as an way of helping every one not a criticism

Car with V8 or diesel - copper coil
Car with turbo motor – inverter welder
Its about the easiest comparison I can think of at the moment.


Hope this helps

Grahame

That's ironic Grahame because that is a comparison I often make when explaining to people. I'll tell you what, I've been using the new Kemppi Minarcmig Adaptive 180 lately and what a machine. The most impressive 240 volt portable mig I have ever used and one of the most impressive 240 volt migs of any description I have ever used. So simple to use and plenty of power (only weighs 10kg too). If I had to find a fault with it, I would say that it should have had a Euro-connect Mig Torch (as opposed to a direct connect type).

Firstly Grahame sorry I called you Barry.

So Grahame excellent piece.

Grahame

I told you I was a punter.

I was told that Argon mix gas was better than CO2 for low carbon mild steel welding???

I had a small disposable CO2 cyclinder attached to the MIG.

And decided to swap over with Argonshield gas cyclinder, [rented cyclinder].

Now it was a few years ago so my memory is failing.

The regulator and flow rates were correct, I double checked; the regulator may not have been working?? The gas was flowing.

Anyway with exactly same settings of wire speed and voltage level as when on CO2 the tip seemed to deform??

I changed the tip, swap cyclinder back to CO2 [different regulator or was there a regulator] and no problem??

On the topic of aluminium transformers and the sale persons comment would suggest that it was just sales talk.

On the issue of inverter welder; are these migs? or Tig and or MMAW.

Cheers

Pulpo

Hi Pulpo,

I can only answer your question on inverter welding power sources on the basis of my some what limited knowledge.
Inverters come in MMAW,
In standard machines AC input power input comes in at 50Hz and is routed through a transformer and sometimes a rectifier. The out put is reduced from line voltage .It sounds like a simple statement, but GMAW and Stick machines have quite different power sources capable of different applications to each other. One type cannot power the other.

Inverter welding power sources bring power in at 50 Hz at switch it through multiple transistors and the wave form ends up around (can’t remember clearly) but I think it is in the multi thousand Hz. It is also rectified back to DC.

Remember that Mig and Tig are different power sources, so the inverter power sources are different
The thing we need to know is what happens at the pointy end. Basically the power change affects the properties of the welding arc to a point where it can be electrically manipulated to achieve desired results.
That’s about the limit of what I can remember. Until recently I was still in the ranks of the dinosaurs and had only used an inverter type source once or twice .I recall something called an OTC Tig that was big as fridge and had more dials ,bells and whistles than the cockpit of a Jumbo jet. About the only thing that impressed me was the ability to drive it from the Tig torch handle .That and the first series of Eutectic small esky sized welders that I saw with my own eyes, disassembled, the boards (choked with coal dust) washed with industrial detergent and hosed, then dried and reassembled. It worked after assembly Believe it or not, this was at an open coal mine here in the north. The lekkies told me it was a regular thing. The arc used to make a squeeking sound when you welded.

Hopefully Bez can bring us up to date as my knowledgelimited is only what I was able to understand from my training in 1989. If I have got something wrong maybe he can give us the correct info or add to it. It will have improved dramatically by now.

Confused yet?

Cheers Grahame

Originally Posted by Pulpo

One other question, apart from weight, what is the difference between copper and aluminium transformers? A sales person informed me, nothing except aluminium was cheaper.
Pulpo

Pulpo. I am a welder, not a lecy, so I can't explain the reasons why, but in answer to your question, I have found that Copper transformers will generally run a higher duty cycle than ally. I have an old, make that very old, goodall stick welder. I hunted high & low for many years to find one rather than buy a new machine. After I had given up looking, a new aquaintance, Now good friend, offered me one that didn't work. Cost a doz stubbies to have it fixed, but she is a ripper. Unless you want to pick it up.

I would expect Ally Transformer machines to be cheaper than copper, but as has already been said, you get what you pay for. A quick 2 min have a go before you buy session may not show any great difference between copper & Ally, but as you said yourself, sometimes you weld all day, & that is where I believe you will find the shortfalls of Ally transformers.

I imagin it is possible, that with the modern electronic components they have found away around these issues, but I imagine Bez would have a better idea than me. These days, I only weld when I have to.

Steve

From an article here, if copper had an electrical conductivity of 100, then aluminium would be 59. So that would explain why [with copper] you can achieve higher currents and have better quality transformers overall.
Aluminium is one of the best conductors of heat though, it is also cheaper and lighter than copper. Cheaper is the main reason they are used.