Miller Thunderbolt XL Welder

I bought the son a Thunderbolt XL, 225AC/160DC @ 20% duty cycle, 230vac, with "infinite" amperage adjustment. $409 street priced.

It has a electrode selector switch for AC hi/lo, DCEP, DCEN, fan cooled x-former, a decent electrode holder but a sucky ground clamp. I added Tweco twist-loc cable connectors.

The unit duty cycle goes up as the weld amps go down so it's rated 100% @ 65AmpsDC and 100AmpsAC. At 125A/DC it's rated at 25% duty cycle and good enough for 1/8" 7018.

The machine can be wired for 115v according to the manual so I pulled the cover to take alook to see what it was wired for, comes 230vac ready. It uses a pull thru shunt transformer that has guides that can be tighten to keep any chatter down. Plastic guide and crank screw so be careful. The other thing I noticed is the x-former is not thermo protected so watch exceeding the duty cycle rating.

Of course I couldn't let him be the first to try it so I fired it up today. I was impressed for a small buzz box. I'm pretty proud of my 50yr copper wound Lincoln AC buzz box arc and the Miller was comaprable on AC. DC with 7018 was ok with a fairly stable arc although it took a few rods to break it in. When I tried the first 1/2 rod it spurtted a couple times so I let the machine cool, then burnt the other 1/2. Did this for a few rods then poured the coals on. After about the 10th rod the machine smoothed out and didn't stutter any more and the heat range stablized as it was welding hot (according to the dial) when I first started.

Next I tried scratch start Tig. The machine is rated at 30Amps low and is too hot for a piece of 20ga SS scrap so I used a 1/16" wire dropper resistor on the ground. Was not too bad of an arc. I've used better 115vac invertor Tig machines tho.

I have a few tanks to make the next couple months so I'll let you know how it welds but over all for a cheap AC/DC machine it's worth the cost and welds decent. Why I didn't go with the Lincoln AC/DC is the Miller had the infinite amperage adjustment, a better heat control setting.

T_Bone

Well it's an old welder trick from before the fancy machines with low amperage dials. You take a 36" length of filler wire, wire diameter and material type determines how many amps are droped, and vise grip clamp one end of the filler rod on the welding bench and the ground clamp to the other end of the filler rod.

This will take a minmium 40a machine down to 10amps or lower if you want. Be very careful as the filler rod will become cherry red while welding and will severely burn you in a heart beat. I use SS filler wire as it doesn't seam to hurt the rod so it can be used latter. Different metals of filler rod will have different heat ranges and won't work as well as SS.

On some machines I like to drop the amps to 5a or so then use the machines amp control to raise to the desired weld amps. To small of wire and it'll burn the rod off.

I have a 22ga SS tank to make and a 1/16" dropper is to large so I'll try a .035 or maybe two .035 wires.

T_Bone

I suggested he take the Lincoln AC thats been in the family for many generations so he could pass it along to his childeren while quivering my voice with a tear rolling down my check adding a few snif's in there.

Didn't work, he said he would be over to pick up his "new machine" :) And after all that I've done with him. Just hard to get respect from childeren now days! LMAO

T_Bone