Monday, June 9, 2014

TIG/Stick welder

Recently bought this China-made, unheard-of brand inverter type DC power supply for GTAW/SMAW


* 10 to 200A (who knows how accurately it can reach those upper/lower limits).
* 60% duty cycle at 200A, 100% at around 150A.
* TIG polarity fixed at DCEN.
* Continuous/pulse TIG (still no idea what the frequency range is).
* No preflow; postflow fixed at around 4sec.
* No upslope control; downslope adjustable from 0 to 5sec (though it doesn't feel like it runs that long).
* 2T/4T setting but latter is pseudo 4T -- pressing the torch switch turns the arc on, arc remains lit when switch is released; pressing it again and releasing it turns the arc off (if downslope is set to >0 then the arc decays accordingly).
* No foot pedal and won't work with one; strictly on/off switch activated.
* High frequency start (wouldn't have bought if it didn't have HF)
* Digital readout only displays main amps setting.
* Air cooled torch.
* DINSE connector for ground and SMAW leads.
* Integrated gas and electrical connector for TIG torch.
* Internal solenoid for shielding gas flow.

First time to TIG weld so am still at the bottom of the learning curve. It's not easy at all. Particularly with my ever deteriorating eyesight. Am specially having problems with stainless steel. Judging from the color of the welds on the thin gauge scraps I'm using, I am overheating the metal even with the amps turned way down low. I've had better luck with mild steel.

They say that a newbie shouldn't train on a cheapo portable AC buzz box because it's just going to be a maddeningly frustrating experience that could eventually lead to a fear of or revulsion to stick welding. Well, I've proven that warning is indeed true. When I tried out this welder's stick mode I was instantly--as in within a second of touching the electrode to the work piece--blown away by the ease of starting an arc and laying down a bead. The arc was smooth as silk. Let me just repeat that for unmistakable emphasis: The arc, the sound it made and the puddle were soooo lusciously smooth and creamy. No electrode-sticking problem at all with the 2.4mm E6013 @80A (which was the very first setting I used when I fired up the machine). After using up half the rod, I switched over to 2.4mm E6011. Couldn't strike an arc--kept sticking. So I bumped the amps up to 90 and bingo! Got an arc going without a hitch even when I wasn't feeding the rod fast enough (because 6011 burns fast!) and had to relight on the fly a couple of times. Did not at all get a charred flux coating on the remaining rod as I did months back on the buzz box. Used up three quarters of the stick and then swapped it out for a 3.2mm stainless rod. Dialed the amps to 110. Laid out a bead on the very first attempt with no flame-out issues. 

If there were any problems, it had to do with my travel speed, arc length, electrode angle and amp settings which I have yet to fine tune. (All tests on DCEP, on 3/16" mild steel plate. Ground setup employs my McGveryism of using copper coated steel wool as interface between the ground clamp and the workpiece for very reliable electrical contact.)

Without any hyperbole I can honestly say that using this inverter has rectified (ha! pun intended) my fear of SMAW.