Arc Welders - Cheap vs Expensive

weldequip said:

As mentioned above, a 180amp Inverter MMA (stick) welder would be your best option for that type of work

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Why do you consider this a better option than a simple 180 amp transformer-based arc welder, please?

An inverter is relatively expensive and has hundreds of electronic components, any of which can blow and make it totally uneconomic to repair.

A transformer-based arc welder is dead simple with virtually nothing to go wrong, and costs peanuts. It will also make a fine job of welding heavier bits of metal.

I was thinking more suitable for that type of work than a MIG (unless you double your budget).
Advantages with Inverters:-
Very lightweight & portable
DC output instead of AC so lay rods down a lot nicer + advanced features such as 'Anti-Stick' & 'Hot-Start'.
Ability to set up basic TIG function.
Disadvantages with Inverters:-
As you have said, complex electronics = more to go wrong & usually not easily/cheaply repaired.
With either you will be able to weld much heavier stuff compared to a similar sized MIG.
weldequip

You want to be looking at spending £150 - £200 for a decent AC transformer machine aswell by the way, the 50 quidders are toy-town & not up to the job
weldequip

weldequip said:

You want to be looking at spending £150 - £200 for a decent AC transformer machine aswell by the way, the 50 quidders are toy-town & not up to the job
weldequip

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I've taken the cover off my £19 arc welder, let alone £50. Brand new too, albeit a special offer. All it's made of is:

1. A steel core for the transformer. I'm no expert on transformer design but it looks perfectly adequate to me. I don't see how paying more would get a better core. It's just a lump of metal plates.

2. The wire which is wound around the core. This is well insulated and looks high quality. The pure physics mean the wire has to be a certain diameter and it is. I don't see how paying more would get better wire or insulation.

3. A heat sensitive trip switch. I can't tell the quality of this, but I'd be surprised if it wasn't up to the job and it would be low cost to replace in the highly unlikely event that it should ever fail.

4. The main power switch. This looks perfectly adequate to me. I'd be amazed if it ever failed and, even if it did, it would be easy and cheap to replace.

5. The fan. This is a standard, good quality-looking fan. I wouldn't pay a penny more for a better one.

I was the main winner with this arc welder. I'd only pay more if I needed a current over about 130 amps.

The main losers must be everyone in the supply chain. How can anyone have made anything? It was almost like a free gift. In this case I didn't just get what I paid for. I got a lot more.

In conclusion, I totally disagree with your comment that low cost arc welders are "toy-town & not up to the job".

Calm down Georgie, boy! I suspect that the duty cycle of your welder is pretty low. I would also suspect that there are very few power settings (2 maybe) on your welder which would make it less versatile. I also suspect that it is very cheaply assembled. As you say yourself 'how can anyone have made anything?'. Well the answer is they made it for almost nothing so they can sell it for almost nothing. In my experience, you almost always get what you pay for.

In conclusion, I totally disagree with your comment that low cost arc welders are "toy-town & not up to the job".

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Horses for courses. If you want to stick bits of metal together over the weekend & are happy sitting down with a cup of tea waiting for the machine to cool down after laying a couple of rods, then the £19 Aldi special is fine. (sold to them by the way because nobody buys them anymore & the manufacturer needs to off-load them). If, however, you need to repair digger buckets & cattle grids...as in this case...something a bit (lot) more substantial is required; and there can be a world of difference in what's inside.
If the welding can be done more or less in situ.(long leads can be used) you won't go far wrong buying an old oil cooled Oxford...they'll still be going all day when the 19 pounder has been recycled into aluminium coke cans & baking foil
weldequip

Like weldequip said Horses for courses. Well they all do more or less the same thing so you need to figure out which would be the most useful to you
ark is more versatile as you can use it inside or outside and can weld heavy material relatively cheaply
mig is much easier to learn and its cleaner and quicker and it's much better at welding lighter material it can also weld heavy material with some prep which you will need to do for ark as well mig doesn't like being outside as the breeze blows the gas away
There are good and bad ark welders just as there are good and bad mig welders transformer based ark welders are very reliable and come it two types
oil cool and air cooled. oil cool usually have 100% duty cycle but are bloody heavy for moving around air cooled usually have lower duty cycle depending on how much you want to pay I would also stay away from the really cheap ones and if possible get one with AC & DC. Inverters are very handy ark welders they usually have good duty cycles and can do ac & dc but if they break down it's impossible to get them fixed
if you only use the welder in the workshop then mig would probably do as you have been managing with a 150 amp welder up till now then something around the 200+ mark with a decent duty cycle should do
proper prep and just do multiple runs and most welders will weld heavy material as you probably know from using a 150amp machine
as with everything you get what you pay for but sometimes you can get a bargain but you wont get it from Aldi their welders are fine as a second welder in case you need to do so welding outside the workshop once in a while but are not capable of being your primary welder

archie.henderson said:

Calm down Georgie, boy! I suspect that the duty cycle of your welder is pretty low. I would also suspect that there are very few power settings (2 maybe) on your welder which would make it less versatile. I also suspect that it is very cheaply assembled. As you say yourself 'how can anyone have made anything?'. Well the answer is they made it for almost nothing so they can sell it for almost nothing. In my experience, you almost always get what you pay for.

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I rarely agree with the idea that you get what you pay for. It varies from item to item. With this arc welder, I got a lot more than I paid for.

There are no electric power settings. The current is controlled by a simple lump of metal which is shunted in and out of the transformer core. It's simple, it works and there's nothing to go wrong, as far as I can tell.

It is most certainly not 'cheaply assembled'. It looks well constructed and fully fit for purpose.

I don't know what the duty cycle is but if it proves inadequate (and it may not) then it should be VERY cheap and easy to improve the duty cycle simply by adding a second fan, or some other way of keeping it cool. How would a more expensive arc welder have a better duty cycle (at maximum output)?

GeorgeB said:

How would a more expensive arc welder have a better duty cycle (at maximum output)?

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An industrial arc welder will have a higher duty cycle and also do DC welding. Usually its rated output is at a 60% duty cycle.

Mine is 60% duty at 300 amps. 30% duty cycle at 475 amps.

I bet yours is 10% at its max and is AC only.

Well, Georgie, maybe, just maybe, you've got yourself the deal of the century. However, I'm sceptical but since I'm not up for arguing the toss we'll have to do that frightfully boring thing and agree to disagree.

shenion said:

An industrial arc welder will have a higher duty cycle and also do DC welding. Usually its rated output is at a 60% duty cycle.
Mine is 60% duty at 300 amps. 30% duty cycle at 475 amps.
I bet yours is 10% at its max and is AC only.

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But how is it designed to have a superior duty cycle than my approx 130 amp arc welder? I wonder if it is. I've yet to have my arc welder cut out when I'm using it at the lowest setting of about 40 amps. But it has cut out, when I use it for too long on the maximum 130 amps. It's probably not far off 30% duty cycle at 130 amps, just like yours, at your respective, maximum setting (475 amps).

So is it 'toy town' simply because it's a low-ish powered (130 amp) unit and all I need? Of course, your welder would cruise along at 130 amps. I guess this is only because the tranformer core is much larger (so it can supply 475 amps) and can conduct away the heat. I suggest the only difference is the size of the core, and nothing else, even though extra fans will always help.

Unfortunately adding more fans only works if the air flow is the limiting factor in the heat removal process. The surface area available for heat transfer and the thermal conductivity of the material are also going to be important factors.

As Shenion says, it's probably AC only so there are no rectification circuits in there. Makes it cheaper and gives poorer welds.

If at the end of the day you're happy with it and it serves your needs then great. But please don't take umbridge at others saying it's really not all that. People like Weldequip have been dealing with welders for a long time and know what they're talking about.

archie.henderson said:

Unfortunately adding more fans only works if the air flow is the limiting factor in the heat removal process. The surface area available for heat transfer and the thermal conductivity of the material are also going to be important factors. As Shenion says, it's probably AC only so there are no rectification circuits in there. Makes it cheaper and gives poorer welds. If at the end of the day you're happy with it and it serves your needs then great. But please don't take umbridge at others saying it's really not all that. People like Weldequip have been dealing with welders for a long time and know what they're talking about.

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I thought you were calling it 'toy town' and implying it's junk because of the price and brand. I doubt if any Clarke arc welders (transformer type) have a DC mode but I doubt if you'd lay into their top of the range transformer-based arc welder. I suggest there's not a jot of difference, apart from the power rating. 130 amps is adequate for my needs and for many people, I would have thought.

Moreover, I understand AC is preferable for arc welding on steel. An elderly, retired welder who I met said he would never use DC for arc welding steel so if AC was good enough for him, it's probably good enough for me and most 'beginners'. DC strikes me as something of a speciality and not really an argument for saying my arc welder is 'toy town', just because it doesn't have DC.

I don't think anyone is trying to mock you or your welder. My reading of this thread is people are suggesting it is very difficult to offer useful advice when there is someone defending their own point of view to grim death and to that end will not allow anybody else to get their point of view across.

I'm sure Scraggydog64 appreciates your advice, but I'm sure he might also appreciate advice from other members. The wider the range of advice and ideas the better informed his decision might be.

For my own point of view I hammer bits of metal together in a forge. I think you are crazy spending £15 on something as complex as an arc welder when a few simple bits of coal can do the job perfectly well.

Ok all iv not read this thread all the way through as it looks like weldiq, is promoting portamigs, and george is trying to tell us that hobby stuff is robust enouth for farm work.......... Is that the Jist?????

Scraggy, Iv worked in this area for years, as well as construction, I can tell you, a hobby arc aint up to the job, nor TBH is a portamig 185........

I run 2 big MIGs a couple of inverters, a small MIG and a couple of TIGs as well as having a couple of oil cooled arcs about.......so without sounding arrogant (which I possibly can be) the advice is fairly traveled......

If your wanting to carry the machine round the farm and stitch up repairs, then an Inverter is the job, a decent well made machine is very robust, and fantastically portable, If however your going to drag everything to the shed, a big old 3ph oil cooled, would be far the best choice....... If you have the budget, GET BOTH.....A light/med industrial say 200 amp MIG (theres lots that will come in budget) and in all honesty, A Lincoln compact welds just the same as a Murex/Miller/ESAB/kemmpi its normally how you find the service and the deal on the day that sells the machine.........

But a 200 or 185 amp MIG will struggle to do all the work on its own, But a 200 amp> oil cooled will except the odd bit of tin work

malcolm said:

I don't think anyone is trying to mock you or your welder. My reading of this thread is people are suggesting it is very difficult to offer useful advice when there is someone defending their own point of view to grim death and to that end will not allow anybody else to get their point of view across. I'm sure Scraggydog64 appreciates your advice, but I'm sure he might also appreciate advice from other members. The wider the range of advice and ideas the better informed his decision might be. For my own point of view I hammer bits of metal together in a forge. I think you are crazy spending £15 on something as complex as an arc welder when a few simple bits of coal can do the job perfectly well.

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Malcolm - I'm just keen to understand why they consider my arc welder to be inferior. I hope the debate is interesting. I wondered how duty cycle is determined by design and I'm still not sure. I trust I'm not trying to deter anyone else from putting forward their points of view. Further ideas on build quality, duty cycle and the relevance of DC for arc welding steel would be interesting, for a start. I totally agree that the wider the range of advice and ideas, the better informed Scraggydog64's decision might be.

To answer your question as to how a more expensive transformer can influence duty cycle, transformer size is not the only variable. Transformer quality (of construction and materials) can determine efficiency, i.e. how much of the input power reaches the output. The difference between input and output power is dissipated as heat. So while a larger transformer will heat up less for a particular power loss, a more efficient transformer will have a smaller power loss to dissipate to start with.

Another variable is open-circuit voltage. I gather that some electrodes are supposed to work best a high-ish OCV. The 6013 rods I bought require, according to the packaging, a minimum 50V OCV. My cheapo arc welder claims 48V OCV, which Im hoping is close enough - just measured it and it ranges from 39V to 46V over the current range. I don't know how this compares with more expensive 160A AC welders and I haven't actually used this particular welder yet.

I hope the really cheapo arc welders aren't total rubbish because I bought one of the Aldi ones a few weeks ago to get back into arc welding. I had a £50 SIP (Weldmate 140?) about 20 years ago from Argos because I could afford neither a MIG (starting price about £500 back then ) nor to pay someone to weld my Minis at £10-£15 per hour. I taught myself to weld thin bodywork (Minis, remember?) with an AC arc welder out of necessity. There's no way I would consider that now that I have a MIG (albeit one of the crappier ones).

Then again, I take your point that with the complexity of a MIG compared to an AC arc welder, a cheaply-constructed MIG has the potential to be a lot worse than a cheaply-constructed arc welder. I bought a SIP MIG so I should know...

After all this time I expect to be rubbish with a stick welder so it'll be hard to tell whether it's me or the box. I do wish I hadn't given the SIP 140 away many years ago when I moved house

D/C is cleaner, and better for positional, also top end inverters, will have software to control the arc.... Duty cycle, is always an issue on little buzz boxes, as is power consumption there fine until you start to crank em up for periods of time...... A/C is better at higher amps 250> D/C will start to cause blow, or wander, due to the build in magnetic field.......big transformer units and A/C D/C tig inverters give you both for this reason........

Its horses for courses, Id lay money down, that I could cook a cheep a buzz box in a day, however I certainly would not expect someone who welds for an 1Hr a month to spend the money on some of the kit I have.....

Design is; ultimately determined by cost. Isn't it the case that; in the more expensive equipment, the manufacturers can; use purified copper wiring (less resistance = less heat & better efficiency), electronic components to higher tolerances & quality, better internal air flow layout and, indeed, design for a completely serviceable machine as compared to the more cheaper (disposable?) machines that use recycled copper, cheaper components, non-user-serviceable parts etc... Don't all these things (and more) affect the duty cycle, reliability, quality of weld, longevity, user friendliness?

These are all important considerations for a welder in business, as opposed to, a hobby welder. In my own experience I have found (mostly) that I do get what I pay for, as indeed I (have to) provide my clients with a level of service that equates to what they are willing to pay for.

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Scraggydog64 - It's a good idea to ask your local welding supplier. They will be able to offer you good recommendations and your choices will, most probably, be determined by serviceability, price on the day and availability of consumables. You'll also make a valuable contact!

Hope this helps!

GeorgeB said:

Malcolm - I'm just keen to understand why they consider my arc welder to be inferior. I hope the debate is interesting. I wondered how duty cycle is determined by design and I'm still not sure. I trust I'm not trying to deter anyone else from putting forward their points of view. Further ideas on build quality, duty cycle and the relevance of DC for arc welding steel would be interesting, for a start. I totally agree that the wider the range of advice and ideas, the better informed Scraggydog64's decision might be.

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It is certainly an interesting subject for a debate, and one that might be best given it's own thread rather than distributed around various "which welder to buy" threads.