Thread: Starting and ending a weld

Originally Posted by Grahame Collins

Say that you both had the same brand and model of welder and plugged in a set your machine at the same amps indicated on your identical machines.
Its entirely possible that the amps delivered at the electrode could be vastly different.

I've heard some people say the power even varies during the day so things are okay in the morning but terrible late in the arvo.

When I installed an air-conditioner (15 amp supply) I tried it during commissioning using a 20 metre 10 amp extension cord. It didn't work and although I had 244 volts on idle it dropped to about 210 on full load. The line end of the extension cord stayed at over 240 volts. When the unit was powered via a proper 20 amp sub-circuit all was okay. I was amazed to see such a voltage drop across the cord. It was a good demo of how a cord can overheat and catch fire.

I haven't monitored the mains voltage at the welder. The power supply and wiring here are pretty good but I do have the welder on the end of a 10 metre 15 amp extension cord. Nothing gets warm (even after my 120 amp long welds test) so I haven't bothered checking any more.

I've attached a photo of today's welds. The gap for each join was 2mm and the rod was 2.6mm. All in the top row were at 80 amps. The first two in the 2nd row were 90 amps; the next two were 70 amps; all the rest were 60 amps. A large version of the photo is at http://phelum.net/temp/P1020721-1280.JPG. I don't think these welds are as neat as some of the original welds (2mm rod, minimal gap) but they are biting into the base metal much more than the originals.

Grahame and DJ, thanks again for all your help. This has been an excellent lesson for me.

Its always a pleasure Steve
Its how we get our Jollies.

Grahame

I've heard some people say the power even varies during the day so things are okay in the morning but terrible late in the arvo.

I have found that where I work, the power fluctuates greatly during the day to the point that I have to adjust my mig when I first start work at 8 o'clock, again about 12.30 and again at around 4.30. It's not so bad a middle to high amps, but when trying to verticle ups and welding sheet metal a thin as 1.5 it get's very bad.

The bad power seems always to coincide with the peak power times ie: Breakfast, lunch and after work. Maybe every one turns on their aircons about 4.30pm.

I don't notice any real difference at home with my stick welder, but then I always weld on the hotter end of the scale anyway.

phelum, it's nice to see that you are trying new things, welding isn't rocket science, if I can do it, anyone can. Just remember if it's not working, try something different, you have the technique, now it's just practice, practice, practice.

Just another thought, regularlly change your clear lenses and clean the filter lense with soapy water.(Don't wash an auto darkening lense.) This will make seeing the weld much easier. Most welding shields come with a standard shade 11 filter lense, this is too dark for me for general use, I use a shade 10 and maybe a shade 11/12 for heavey work.

From my experience the clear lenses tend to go opaque after a little use. At work I change mine every day for heavey work and if I'm doing sheet metal work about every week. This will change with the quality of the lenses, at the moment they are buying Elliot clear lenses and they don't last at all. They were buying a lense made by cigweld and they would last half as long again, it seems that you get what you pay for. Grahame may have a comment on this, he's been around longer than me.


That's just my experience.

Robert