Welder

The problem with the "little" el cheapo 140Amp stick welders is that they're little and el cheapo..

You're getting a voltage drop from the "undersized" welding leads. You can strike ok, but it collapses as the welding leads increase resistance due to heat and the inability of the wires to carry the current properly.

Had a boss that had one of those, asked me to glue some 6mm plate together. I laughed and brought my old school 200Amp WIA welder and got the job done. Never had any luck with his welder till I upgraded the leads (to real 16mm² welding lead wire)and shortened them a little(about 50 cm). It was ok for small stuff up to 3mm mild steel.

Adding capacitors will NOT improve arc starting on your modified to DC stick welder, it will just give you hearing loss from loud bangs. S.M.

You need to add a fairly large inductor to the output to stabilize the now DC output.

A large transformer from an old battery charger may work well enough if configured properly.

You will need to wire it up so that the high current DC travels through the secondary windings in a parallel winding configuration opposed to the most common center tapped series configuration that most battery chargers use (less voltage drop more current capacity).

If you are lucky you may even have a transformer that has the primary windings on the outside where you can easily cut them off being they will no longer be used or needed.

The only other option is to just buy a good and proper sized welder of course!

It will have a limited duty cycle of course but at least you will have a smoother arc to work with.

Further to the inductor idea, I cant see that it would matter, but does it make any difference in which lead the inductor is connected..? the earth lead, or electrode lead...? or is it necesary for an inductor in both leads..?

Norm.

Hi Norm;

The magnetic field collapse of your inductor creates extra varying voltage at the time the arc is struck and that varying voltage should also help you to better stabilize your arc and possibly also increase your working distance on the rod. If you don't have enough inductance in your inductor that you are currently using, you might add another inductor as long as it's current carrying capacity in amps is sufficiently high enough and it's internal resistance is not so high as to cut your power capacity and/or to limit your operating duty cycle.

Lowell

From memory, the inductor coil went around the work lead, not practical with a car coil, but any coil will do and the closer to the lead copper the better, have a look on the web. The back EMF is a very high voltage for a very short time, but enough to ionise the air gap and keep the arc going.

Tony

What size rods are you using? I had the same problem with an el cheapo buzzbox. I found the thinest rods and was able to hold an arc.

Thanks guys, The leads are obvious now that you mention it, and the idea of inductors in the output has merit. The thought of a bigger welder had crossed my mind but my usage is limited such that I could hardly justify the purchase of same. anyway guys thanks again. Norm.

All of the leads. The stinger, the ground, and the power supply cord should all be as short as you can stand them to be.

The stinking part of this is, you can probably purchase a new machine for the price of replacing those parts. The new one will, most likely, come with long thin leads as well.

Well I bought my stick welder an age ago(paid $200 for it, and its well earnt its keep since ), but I keep a weather eye on ebay. Good old school stick welders (200Amp single/2/3 Phase) go for around $40 to $60. Getting one within travelling distance is the challenge.

My WIA welder can be wired for single or 2/3 phase, its ok on single phase up to around 150Amps or so and then I start melting power plugs and sockets.. (Oz is 240Vac 50 Hz with a 10 Amp limit on the "GPO" general power outlet, 15Amp outlets are available but not usual in domestic situations.(explanation for our overseas participants))

My only real complaint with it is that as I'm getting older its getting heavier to lift ....

I see you already had one suggestion from another engineeer for adding a reactor in series, which is what will really help you the most in order to keep your arc stabilized and struck. You can obtain a 1.41 gain in voltage plus some stability from adding as really a large as you can get capacitor across the output of your bridge, but you shoule still use a reactor in series with it's output which should really do the trick! Also you should use smaller rod also because the larger rods will short out very easily and will not sustain your arc as well with as low an amperage as you have availabe from this unit.

Everyone agrees that 200 Amps is the Best! My father and I built a 200 Amp welder using a 200 Amp Aircraft Generator and we had the Machine Shop at Idaho Power Company wind a reactor with about 12 turns on it of large rectangular wire around a large iron shaft which we put on series with the output from the generator which worked great!

The answer is the same as... How to get to Carnagie Hall? (!)

If it realy is the machine... Make Sure the Rod Size ( Good Quality Rod )is for the Volt / Amp Setting. & D.C. Rod for D.C. Setting & A. C. Rod for A.C. Setting.

And Correct Polarity For the Rod... ( See #15.)

Hi Tony;

Great Idea! The pulsing will surely stabilize the arc so it won't die, by continuing to pulse it, in effect almost to re-strike it at high speed intervals. Kind of reminds me of the rotary spark gap on the old tesla coils that created arcs of very long lenght at high frequency! I'll have to remember this one! Much less expensive and a lot easier than consructing an rf plasma exciter, and a lot less expensive too. Keep em comin!

Lowell

G'day mate...have you still got the manual.. it might illuminate your problem.. failing that, go to a welding supplier (Not Home Depot or Master Home Improvement) and up-grade to a "fit for duty" machine.

It sounds to me that your machine as dinky and as cute as it might be, might not be man enuf for the job... you got buckleys mate!

Hey Pommie, you an ex-pat Aussie? Poms don't use the phrase "You've got Buckley's" (=You've got Buckley's chance =You've got no chance. Buckley was a convict who escaped and lived with aborigines, where he was found years later). Now if you'd used Hobson's choice ....

Way to many years back and fro to Oz... and working all over the the world with stubby drinkers & threw a leg or two over a sheila...I guess it kinda rubbed off..