Arc Welders - Cheap vs Expensive

[Wozzaaah]

George, it's not an issue of proving anyone wrong or right, you've set yourself the goal of being able to welding thin steel with your machine. If it works or not, at least you'll find out what you and your machine are capable of and hopefully it will put this subject to bed whatever the outcome .
I wish I was nearer, I'd love to join you at the meet, even if just to say hello .

 

[snowcat]

George, you are on a hiding to nothing, the facts are, without a high OCV thin material is much harder, I have welded bellow a 32" with an oxford running a fincord M and 80V and at 1G (flat), this is hard even with years of experience and decent machine and consumables , now get positional and it becomes nigh imposible........these days I wouldn't even think about it thats what TIGs and MIGS are for, if you want the old school way gas is the way I was taught....

the more experienced you are the less important the machine, as a decent man with even poor kit can make a reasonable attempt, however put a nice machine in the hands of someone inexperienced and as long as its set up away they go.....

I really am lost with your persistence with wire feeders, I have one plant that at 20 years old still burns strong.....

 

[Drains]

My turn!

George, it's not that everyone is against MMA on thin metal - you're getting the wrong end of the stick there (scuse the pun). The point is, it's more difficult! There are plenty of folk find mig on thin material difficult.. yet it is much more easy, relatively, than stick.

Re the challenge - with a meeting of plant, everyone should try all the other bits of plant too, and all the other rods brought. Wouldn't take long, but would be interesting. I'd be there like a shot, except for the 400 mile factor.

I'll bet George, you would do best on a quality inverter, whilst Snowy would make a good job of all of them (except he'll do best on the inverter as he'll change the polarity when no-one else is looking)

I also enjoy the challenge of welding thin on the stick - occasionally I have to - but if it comes to an indoor job - it's mig/tig all the way.

 

[GeorgeB]

There's the process and then there's skill. To go for building up the skill to weld really thin stuff with an arc welder is really impressive to me, and I'm sure your experiences will be useful for many others.

Thank you for your response and the three or four which follow...all great stuff. The reason I'm inspired to try and crack this arc/thin sheet thing for myself is that I've read a few others say they can do it, or have seen a few others who can.

I'd also ask if there are any/many images on here from where relative novices who have succeeded in getting a good result on 0.7-0.8mm steel sheet with their MIG welder. It's great when people post images to show their results but many of the samples are on metal which seems to be at least 2mm thick, and often mid-sheet, too. I have succeeded, by luck or whatever, in doing short runs with an arc on thin sheet, some of which are better than others but I can't yet get good results consistently. Once I figure out a process which I think others should be able to follow, I'll write it up here.

In the meantime, if others know the secret or trick, please reveal it here.

 

[Welderpaul]

In the meantime, if others know the secret or trick, please reveal it here.

Mig.

 

[jugs]

In the meantime, if others know the secret or trick, please reveal it here.

Tinmans Solder

 

[aero]

Lol

My expereience for mma on thin stuff is good quality rods, a set that gives 80 volts and is stable on low power setting plus loads of practice. Being able to notice instinctively when you've putting in too much heat is essential. Using some form of heat sink clamped to the back of the job helps too.

There are far easier methods then mma. I used to enjoy gas welding thin sheets together, but again you have to watch the heat going in.

 

[GeorgeB]

Lol

My expereience for mma on thin stuff is good quality rods, a set that gives 80 volts and is stable on low power setting plus loads of practice. Being able to notice instinctively when you've putting in too much heat is essential. Using some form of heat sink clamped to the back of the job helps too. There are far easier methods then mma. I used to enjoy gas welding thin sheets together, but again you have to watch the heat going in.

aero - Many thanks for this. Even though I'd already hit on the idea of using a heat sink, it's good to get confirmation that others find that the same approach works for them.

I noticed on the label of an Oxford welder on eBay that it said to use 80 volts for thin metal and 50 volts for thicker metal. But the Oxford specs suggest that the current on some models goes lower for 50 volts than 80 volts.

If minimum settings on 80 volts are 30 amps that gives 2400VA

But 50 volts might go down to 20 amps on the Oxford, which would be 1000VA - a lot less power, I would have thought.

I'm confused! Why should 80 volts 30 amps be better on thin sheet than 50 volts 20 amps?

 

[shenion]

GeorgeB, your confusing weld voltage with OCV (open circuit voltage.)

At 30A, the weld voltage is about 18V. The difference between the two voltages is the current slope called droop. Both will drop to the same voltage when welding.

A high OCV will have a more constant-current output as the arc length changes. It will also maintain the arc better as it has more voltage to restart the arc if it misses.

 

[aero]

rods light up better at 80 volts. Voltage is the pressure, current the quantity if you like. Without much 'quantity' you need some pressure to get things going.

Well thats my understanding of it. Lohy rods work better on 80 volts for the same reason, easy(er) strike up.

 

[GeorgeB]

Both will drop to the same voltage when welding.

So once you've got the arc going, and if you can hold the arc steady, am I right in thinking there's not much difference between OCV 50 volts and OCV 80 volts? If so, I would still have expected 50 volts 20 amps to be better on thin metal than 80 volts 30 amps but I'm sure I'm wrong!

 

[zardoz]

I will say one thing about Arc machines, in my small experience, of all the welding types they seem to be the machines where you can expect a half decent level of quality for a cheaper machine. Much more so than a less expensive MIG or TIG. Like many of the cheaper machines of all types they tend to exagerate their abilities, but as long as this is taken into account it should be ok. As long as one uses good quality rods which people with cheaper machines often dont even think about. I know i didnt when i got my first Clark Arc.

 

[Drains]

So once you've got the arc going, and if you can hold the arc steady, am I right in thinking there's not much difference between OCV 50 volts and OCV 80 volts? If so, I would still have expected 50 volts 20 amps to be better on thin metal than 80 volts 30 amps but I'm sure I'm wrong!

The problem with low volts on some electrodes is that much of the time, though you don't notice it, the arc is breaking, so you need the high volts to re-ignite. This is particularly true on AC as the arc is being constantly broken and re-lit. Hence for many rods you need a higher OCV on AC than you do on DC. (you can run very low DC volts on almost all rods - cellulosics being a major exception)

 

[aero]

more pressure then.

It helps me if i look at stuff the simplest way i can.

 

[ben8vgte]

after reading the bit about ocv i though i'd have a play with my new oxford, at 80v it's a lot more stable when trying to fill in gaps in poorly fitting bits, to be honest i didnt think it would make that much difference but it did.

 

[shenion]

Yes, the cheap arc welder I had was tough to maintain an arc do to the low OCV (45v). Get the rod out for a fraction of a second and the arc stops then you tend to stick the rod restarting.

My Airco is 90V. When you break the arc it will maintain an arc until the rod is near 1" away.

 

[Muggins the Mug]

I'm new here, but I wanted to add my tuppence worth about cheap arc welders. I've been eyeing up cheap arc welders for a few years now, having wanted to trying welding since I was 16 (I'm now 40).

I recently bought a dreaded Aldi arc welder (boo, hiss). The first one I returned because the power indicator was way out (the guy on the help line suggested I return it). I got another one only to discover that the chrome was flaking badly off of the earth clamp - time for another exchange. I also wasn't impressed with the nicks in the electrode cable for a brand new machine.

Finally, I got my last one which also was returned for a full refund - calling this a "buzz box" would be an understatement. It was at least 2-3 times louder than the previous ones. The casing must have been badly fitted and to be honest the workmanship on that batch was atrocious.

These exchanges and refunds happened in a short period of time - 11 days to be exact. It's put me off buying a cheap arc welder again and at least I got my money back. Next time I'll be far more cautious about what I buy and will probably do more research into the decent more expensive brands.

Caveat emptor - let the buyer beware.

 

[GeorgeB]

I'm new here, but I wanted to add my tuppence worth about cheap arc welders. I've been eyeing up cheap arc welders for a few years now, having wanted to trying welding since I was 16 (I'm now 40)

Welcome to the forum. I'll take your comments in good faith. There's always a risk that some trader could come on here to help rubbish these great little arc welders, if he fears he might start losing business in selling £400+ welders. I trust that isn't the case with you.

>I recently bought a dreaded Aldi arc welder (boo, hiss).
>The first one I returned because the power indicator
>was way out

Do you mean the metal strip that moves along as the core is screwed in and out of the transformer to change the current? It seems incomprehensible that much could go wrong there, being simple physics. The metal strip indicator will never be an accurate ammeter. It's just a rough indicator so it may have been performing up to spec after all.

>I got another one only to discover that the chrome
>was flaking badly off of the earth clamp -
>time for another exchange.

I doubt very much if they use expensive chrome so I'm not sure what was flaking off but a slightly rough earth clamp wouldn't put me off the entire welder. I fear you were the loser.

> I also wasn't impressed with the nicks in the
>electrode cable for a brand new machine.

Do you mean indents? That doesn't sound great but, again, was it really a show-stopper?

>Finally, I got my last one which also was
>returned for a full refund - calling this a
>"buzz box" would be an understatement.
>It was at least 2-3 times louder than the
>previous ones.
>The casing must have been badly fitted

I would have looked to see if the screws or anything could be tightened. Or add a bit of sound-deadening material to the case. I doubt if the tranformers would vary much in terms of producing noise so it must have been something simple.

>and to be honest the workmanship on that
>batch was atrocious.

It would have been good if you could post photos. Or perhaps someone else can post images of the inside of an Aldi welder so we can judge for ourselves. I look forward to the next appearance of these welders at Aldi because I hope to buy one.

>Next time I'll be far more cautious about what I buy
>and will probably do more research into the decent
>more expensive brands.

I'm not sure what brands there are in terms of transformer-based arc welders. How about the one I posted photos of? The build quality of that is first class.

 

[irondarren]

Cant bet a good quality inverter, my inverter fusion is almost idiot proof, basically if you cant arc weld with that then you will never learn. 96 ocv means it will strike almost any rod with ease, have the rod to far away from the weld pool and it still maintains an arc. get it stuck in the weld pool and the amperage drops away, allowing you to pull it out and the arc restarts instant. Welding 7018s is like welding 6013s and restriking is never a problem. A pretty much perfect weld bead all the time, use quality rods like the esab ones and the flux just drops clean off. It not just the inverter fusion unit that does this, the lorch units no doubt are the same (matt will no doubt vouch for that) as are any quality unit. But you have to pay the money the fusion or the lorch units arent cheap, there are alot of very clever bits inside them, means you should easy be able to produce xray quality welds.
No doubt transformer arcs are becoming more rare, with either cheap and cheerful far east stuff or the very expensive pickhill (old oxfords) or the DC rectifer units by esab.


dont be so tight buy a quality unit, cheap ones end in tears.

 

[Archie]

I'll vouch for the Lorch ones. Completely idiot proof and almost impossible to extinguish the arc.