Arc Welders - Cheap vs Expensive

[matt1978]

Makes a lot of sense - I have pulse on the TIG, and a pulsing technique is essentially what I'll use with MIG for thin metal (only I'll do that manually and I might not be quite so fast on the trigger as a synergic MIG might be, and that's different anyway).

Is the feature is mostly intended for thinner metal?

Yes Malcolm,

Its only intended for thin sheet use..........You still have to use it with thinner electrode diameters if you want to weld at low amps on thin sheets.

 

[bawjaws]

I also note that Lorch give a 40% duty cycle at maximum output for that model. I expect the Powercraft arc welder was something like 40% but the Lorch will receive hero-worship (fair enough if you want to spend that kind of money) whilst the Powercraft duty cycle comes in for ridicule.

no, the powercraft has about a 10% duty cycle for 4mm rods, i have one myself and have fitted a bigger fan to help it, its a brilliant welder for the hobbiest but for the bigger jobs it wouldent come close to the more expensive machines which can burn rods all day when YOU choose to, not the machine

 

[matt1978]

Many thanks for this link, too. I don't doubt it's a first class, professional level machine but, as Malcolm has asked, what makes it more capable than cheaper inverters of welding thin sheet with MMA? (Now answered, thanks) The lorch goes down to 3 amps but I found that 10 amps seems too low for anything, so it would be interesting to compare my inverter with something like that Lorch on pulse. As it is, I'm concentrating more with my transformer based unit, for the time being. I also note that Lorch give a 40% duty cycle at maximum output for that model. I expect the Powercraft arc welder was something like 40% but the Lorch will receive hero-worship (fair enough if you want to spend that kind of money) whilst the Powercraft duty cycle comes in for ridicule.

Georgey Georgey Georgey.........

All of our duty cycles are measured at 40 Degrees ambiant temerture for a 10 minute period. So if your using the machine in a room that is less than 40 degrees, then the duty cycle will increase.........I am not aware of the Powercraft unit you mention, I dont know the duty cycles, but I am would be very suprised if it was 40%.

If you like, I will send you a Book of Welding, where you will see in plain text that from extensive research into the welding equipment market, a high percentage of Data plates on welding machines, have misleading or downright lies on them. This can be, false claims of duty cycles, minimum or maximum outputs of the machines or more often than not all three..............more worryingly claims of electrical safety conformance are often exagerated or completely made up.

Lorch, 100% garrantee any information that its put on there data plates, to give peace of mind too the end customer, Lorch have put in writing a money back garrantee to the effect that if, our machines do not perform as the data plates suggest, the customer is entitled to a full money back refund, this is not just for the warranty period, but for the entire period that the customer owns the machine!

I have posted on another thread about an offer made from a Chinese manufacturer at an exhibition, for some small MMA Inveters. They said that they would write any information we requested on the data plate regarding maximum output amperage and they would also write on the date plate that the units conform to any electrical safety specifications we asked for, even though they quite clearly didn't.

 

[matt1978]

If it has a duty cycle of only 10% for the 4mm rods, what size of rod would that equate to for a 100% duty cycle (if that is at all possible)?

Its not so much the fact its a 4mm rod, its the amperage required to burn thad rod, so maybe, it would be 100% at 40 amps for example, which would be a 1.6mm or 2mm.

 

[malcolm]

Not wishing to be rude. Could we hang fire on this thread just for tonight. It has great potential to be a fantastic thread, and it will be opened again very shortly, but just for now while some discussions are going on, and to be fair to another member I'd rather leave this one for tonight.

Edit> Open again. Sorry for the inconvenience. I'd asked a member not to post for a little while last night as arguments seemed to be developing elsewhere on the forum.

 

[wyn]

Hello Muggins,

I have one of these....A Lorch H150.
I got it to replace a clarke 200A transformer.

There is a world of difference between them. The clarke needed to be run at a high amperage for each rod and the the arc seemed to be a bit all over the place.

The Lorch however has a real nice arc, which is difficult to extinguish even when you pull the rod away. No sticking of the rod on startup. With a 3.2 rod it will keep going all day. It works well with a variety of rods eg.. lo-hy , stainless, hardfacing. I have used it off a poor supply and 60m of extension leads.

Easily portable as you can see from the bottom pic.

Oh! and it's a Tig as well with the right torch.

I'm well pleased with it and all for just under £400. Which IMHO was good for what it can do.

Things have moved on a bit since my first arc welder where the power was adjusted by an external spring type thing ...you moved the clamp along the spring to vary the resistance?

 

[irondarren]

The main advantage of an inverter V a transformer type is weight. you certainly wouldnt drag a transformer type from place to place without a little heavy lifting.

Not so sure about the cheaper inverters, but when you get to the lorch or the inverter fusion ones, they consume far less power so in effect they are more environmentally friendly, so i guess they are a little greener which certainly isn't a bad things.

As wyn says his lorch is a TIG as well, add a tig torch and you have scratch start TIG. Again most of the more expensive ones have a little flick switch that changes the voltage to allow Tig or MMA operation. Not so sure about practical use for car welding as positional TIG can be very hard work.

The more expensive inverters usually have a high OCV often around 95volts, which almost means if you run out of 6013 welding rods a 6inch nail might just pass as an alternative to welding rods. Jokes aside the high OCV means easy striking, in other word less sticking of welding rods. Most 6013 are supposed to have a minimum 50v ocv, interesting that almost all the cheap transformer types are around 48v ocv. So it just makes hard work of striking an arc. I guess for most of the users here they are not going to use 7018 rods, but required ocv on these is around 75v a no no on a cheap tranny type.

The anti stick on the better inverters is great, should the rod stick to the work piece the machine shuts the amperage right down to about 5 amps. This mean it is easy to break off, as soon as it does seperate from the work piece the amperage goes up to where it should be and it restrikes automatically, this is a big advantage for a learner as you are likely to stick a few rods as you begin to learn.

Quality inverters have an excellent ability over cheap transformer types to still weld at low amperages and maintain a perfectly stable arc. Although not practical for welding it is possible to arc and burn (ill use the term burn because its to low a power to weld with) a 2.5mm rod at 30amps.

More expensive units have a much higher duty cycle than cheap units. Cheaper transformer units will weld few, 3.2mm rods in one go then over heat. requiring time to cool down a real pain if you are trying to do a reasonable amount of welding. Even some of the cheap inverters only have a 10% duty cycle at around 140amps. My fusion unti does 180amps on MMA and 200amps on TIG at that power duty cycle is supposed to be 50% (not sure if thats 50% at 40 degrees or 20 degrees) The similar size lorch unit is around the same duty cycle. The baby 140amp lorch reckons 35% at full power. Just looking at the equivilent sealey unit whic is the mw130 (125amps at full power) you are looking at 15% duty cycle, which isnt many 3.2 rods before over heating.

The other advantage over an inverter v a transformer type, this applies to the cheap inverters as well. They are DC, rather than AC that transformer types put out. Some types of welding rods dont run very well on an AC power source. DC give the advantage of runing either DC+ or DC-, having the earth plug into the positive or the negative terminal can effect penetration. DC units will give better penetration than AC units as weld as producing smoother power. AC by its own nature ramps the power to full power then it drops to zero changes polarity and again builds to full power in a sine wave. this means you have a point where there is no power to provide an Arc. in other words you have a stop start welding process.

The last advantage over a quality unit V a cheapo, is one that some might not consider and advantage, it really does depend on how selfish you are. The quality units like the inverter fusion and the lorch are made in europe, the fusions were when i purchased mine made in the UK, the lorch's are made in Germany. No big advantage to that really, except the lorch and the fusion workers enjoy a reasonable standard of working conditions, in a safe working environment, with health care and reasonable pay. The cheap units are made in the far east where the conditions can be unsatisfactory, poor safety standards low wages and no health care. As i said this depends on your point of view, if your more worried about how much change you get out of a few hundred quid rather than the working conditions of the people that make the unit, then it is no advantage. But if you prefer the people that make you tools to enjoy good working conditions that you would be happy to work in, then there is obviously a big advantage to the more expensive European made units.

 

[shenion]

If you do not have an inverter or DC arc welder, look for low OCV rods. An example is 7018-AC my many sources is designed for low-OCV AC welders.

Most of the smaller (2.5mm and less) 6013 rods i have seen have a comment about now supporting low-OCV AC welders. Not as big of a problem as it used to be.

Then again if you just buy cheap, non-name rods you will have more problems anyway.

 

[irondarren]

True enough shenion, i find far better results with branded rods like esab, but at around £22 a box or about $33 in your money. they can be a big expense.

 

[shenion]

For 6013's and 7018's here Lincoln Fleetweld rodsare available at home improvement stores for $10/5lb. Only have 3/32 and 1/8 though (2.4 and 3.2mm).

They work well, slag is a bit hard but does come off (have yet to see any peelers )

 

[irondarren]

photos of the inverter fusion unit, with it set up with Tig torch and adapters the white cable being the foot pedal controller, which is lovely little luxuary.

hmm just thought the photo contains just over £2500 worth of welding equipement, and of course the most important thing a tea cup, shame its empty.

Weldequip might not like the dirty state of the portamig lol. No doubt it will get stripped down and cleaned out over Xmas

 

[scarecrow]

Too well worked machine there irondarren is there any way to measure the ocv of a welder

 

[bawjaws]

certainley been put through its paces then darren!

 

[irondarren]

Scarecrow the ocv is normally stated on the plate on the machine. if its a new machine and the specs are on the internet it normally shows on the manufacturers website

 

[scarecrow]

Just had a peek at the plate at the back of mine and I think it gives voltage ratings for the different amps. does the voltage go and down with the amps it doesn't say ocv anywhere all I get is a v

 

[irondarren]

ocv should be constant, its different from the welding voltage. some manufactures list it as OCV some as no lad voltage basically the same thing. Its the voltage at the torch end with no welding load (if that makes sense).
i would imagine if you got a voltage meter and checked it you can tell, but im not sure but be someone like technical al would know

 

[scarecrow]

I'll stick the voltage meter on it tomorrow it's not a very expensive one so I don't mind if I welds the whole thing together.

 

[shenion]

You can measure it with a meter with no load.

It may not be very accurate with a digital meter. An analog one will actually work better on transformer units. Digital ones tend to measure peaks.

It still may need a small load to get the effective voltage.

 

[scarecrow]

You can measure it with a meter with no load.

It may not be very accurate with a digital meter. An analog one will actually work better on transformer units. Digital ones tend to measure peaks.

It still may need a small load to get the effective voltage.

So it a bit of multitasking for me tomorrow the welding and reading ill try anything once

 

[chriskelland]

a digital meter will be accurate on DC - no peak.

If your meter reads pk - pk volts, then rms is .707.

IronDarren, I have just thrown out a transformer unit and now have a Fusion 160MA and I now know just how right you are about the more expensive units. I could not be more pleased with it. OCV, BTW is 92 V DC.

Chris.