Help with Lincoln Square Wave 300 Welder

Hello, all,
I just got a Lincoln Square Wave 300 welder, mostly for
TIG work. I'm just getting it set up, and have a few questions.
First, when doing AC TIG, with the pulse mode turned off, it has
a very regular break in the arc just about every second. I thought
maybe the pulse switch was not working right, so I tried turning it
on, and the break in the arc was much more pronounced. Is this
regular pulsing of the arc normal, or is there some problem in the
current regulation or something?
Second, this machine is rated at 80 A on 240 V, and the manual recommends
#4 wire for the feed, which I installed. But, the flexible power cord
that came on the machine is #8 (3 cond), and it gets QUITE warm just
running 50 A. Is this the right power cord? Did some idiot change the
cord for a thinner one some time in the machine's past?
Third, I have a miller cooler and a Weldcraft WP-18 (350 A) torch.
When I open the water out line from the pump, I get a very good flow
of water. When I hook the torch to the pump, I get a lower flow, but
it could be about 1 quart a minute. When I connect the torch return
flow to the cooler, the coolant returning to the tank is just a dribble.
It might be 8 Oz a minute, but couldn't be more than that. Is the
torch or the cooler clogged up? (Kind of sounds like it might be
the cooler, or maybe the pump needs a rebuild.) The pump doesn't
prime easily, either, is that a sign of the pump needing rebuild?
If it needs cleaning, what is recommended?
Reply to
Jon Elson
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For AC TIG your high frequency switch needs to be set to "Continuous".
#6 SO or SJO cable is fine.
Pumps heads can be dismantled and cleaned. If the torch is old, buy a new one.
I recommnd the CK 230. It is a #2 series torch that can handle up to 300 amps.
Reply to
Ernie Leimkuhler
OK, thanks. I tried that, but it didn't make much difference. But, maybe with it on cont. the breaks in the arc won't be as noticable. It was really a short break, just a couple of mS.
Well, it came with #8, and it looks so original it is hard for me to believe the power cable has been replaced. But, as hot as it is getting at only 50 A output, it has to be replaced. Thanks for the info.
I think I'm going to get a rebuild kit for the pump, and probably put a pressure gauge on the pump output, so I can keep track of any impending blockage. How hot should the coolant coming out of the torch be?
Thanks so much for your help, Ernie, if I wasn't 2000 miles away I'd gladly take one of your courses! I did some more work with the machine, but I've got a long way to go. I'm beginning to get a feel for the arc, and how to keep the arc length relatively consistant. I think I've been working with the arc too short.
Reply to
Jon Elson
Maybe it is original, but maybe 480V was also original, and it got rejumpered for 240V without changing the cord.
Reply to
Bob Powell
Yeah! That's a good thought! Although, it seems, if the cord was original, it should have been made sufficient for any of the voltages the machine could run on. But, I'm getting a "picture". The guy who sold it on eBay "tested" it. I'll bet it WAS wired professionally for 480 originally, the seller switched the taps for 240, tested it, it worked, and he boxed it up and sent it to me. So, the cord was adequate for 480, but not 240. I'm still trying to find out whether Lincoln sells these with or without cords on them. (Or, whether that is an extra-cost option.)
Hmm, a 20 foot length of 3-conductor #4 cord is going to cost a mint! I wonder if I could find something like that surplus, somewhere. eBay?
I managed to trip a 50 A breaker today, so I had to stop and swap some breakers around (I had already bought them, but hadn't had time to shut everything down and do that yet.)
I finally made a decent 2" of butt-weld in 1/8" aluminum, so I am learning, little by little. Still burning big holes in things, too!
The filler metal technique with aluminum still has me stymied, though. I get lots of blobs, but darn little fillet.
Reply to
Jon Elson
I pay $1.30 a pound for it at one of my secret sources here in So. Cal. If you need some, let me know.
That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell
Reply to
Get your amperage dialed in right and then get your tungsten in until you get your puddle. On aluminum you will be best off with Lanthanted or Zirconiated tungstens.
:anthanted works great on AC or DC, and Zirconiated takes the highest heat of any tungsten on AC, so you can use a smaller tungsten and get in closer.
Here are some quotes from my past posts about TIG:
A basic selection of TIG Rod should include Steel, Stainless steel, aluminum, and bronze.
Steel ER70S-2 The basic TIG filler for steel. It comes copper plated to prevent rust, but keep it in a tube or bag anyway. Sizes: 0.045", 1/16", 3/32", 1/8"
Stainless steel 308L is the standard filler for 304 SS which is the most common type. 309L is a better filler for joining any kind of stainless to steel. 316L is the best for marine work. Sizes: 0.045", 1/16", 3/32"
Aluminum 4043 is the most common aluminum filler rod. It works well for most situations, but... 5356 is stronger, better corrosion resistance and better color match for polishing or anodizing. 4047 is my favorite for welding castings, but it is kind of hard to find. Sizes: 1/16", 3/32", 1/8"
Bronze Silicon Bronze is excellent for joining other copper alloys such as copper, brass and most bronzes. It can also be used to TIG Braze Weld steel and stainless steel. TIG Braze Welding is very useful for stainless steel since it doesn't actually melt the base metal so there is no chromium oxides formed on the back face of the metal. Sizes Sizes: 0.045", 1/16", 3/32"
An advanced selection would include: Some aerospace alloys like Inconel, Hastelloy, or Haynes alloys. They are my favorite alloys for joining odd things and are extremely strong. Pure Nickel is excellent for joining cast iron.. Pure Copper is good for TIG welding copper where it will be seen. ER80S-B2 is the current top choice for TIG welding Chrome-Moly tube for planes, cars, motorcycles and bikes.
As to a vendor. The only guys I know that even list TIG rod on the Web are:
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Great outfit, they carry all things TIG.
You can also mail order from Central Welding at :
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Just call them and they will ship it to you.
Here is an exercise to practice when not welding.
Level 1
Take a 3/8" steel washer. Place it on a piece of white paper. Take a nice sharp pencil. Place the tip of the pencil against the paper inside the washer. Now start swirling the pencil tip around the inside of the washer to draw a circle on the paper. Keep circling the inside of the washer, while nudging the washer across the paper. Try to end up with the washer traveling in a straight line across the paper. You should end up with a long swirl pattern across the page. Keep practicing until the swirl pattern is even and in a straight line.
Level 2
Same setup, with one change. Once again slide the washer across the page while swirling the pencil tip around the inside of the washer, but now DON"T touch the paper with the pencil tip. This means being able to hold the tip of the pencil within a 1/16" of the paper without touching it and without lifting out of the washer.
Level 3
Do Level 2 while standing next to the table without any part of your arm resting on the table.
Level 4
Move to a 1/4" washer.
This exercise comes from a welding textbook from 1929, and it still works quite nicely to train your muscles for floating the torch.
Normally I do not swirl the torch while TIG welding, but this still works as an exercise to build up muscle control.
Reply to
Ernie Leimkuhler
4 conductor #4 "SO" cord is used among other things for trailer hookups, I found a 30' cord for free and made an extension cord from it (using only 3 conductors with nema 6-50 style connectors at the ends).
For welders with 100+ amp primaries, I think they are more commonly connected using a short pigtail of 1" metal flex with individual #4 THHN conductors inside.
Reply to
Bob Powell
CPI surplus has some cheaper, $0.85 a foot. But, the shipping would be expensive. Still, thanks much for the offer. There has to be some closer to me.
Reply to
Jon Elson
Groan! DOn't trust the guys who sell this stuff, I guess! They told me pure Tungsten was best for Al!
I have the Lincoln Amp-Trol finger control. I can see how a welder crawling through a maze of pipes would prefer the finger control, but at my welding bench, a foot pedal sounds a lot easier to use. I'll have to try making one.
Oh, this is good! Thanks!
I tried a butt weld on 1/8" aluminum last night, and got about 2" of really good-looking weld (the rest was awful). I broke it apart with a pair of pliers (it was clearly less strong than the parent metal) and broke with a very wavy line, so I think the weld puddle broke away from the unmelted parent metal. At 1/8", maybe this needs pre-heating.
Still lots to learn, but some signs of progress. And thanks VERY much for all your help, Ernie!
Reply to
Jon Elson

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