Eco mod my welder

[oil pan 4]

My newest welder ecomod is to power my mig welder off a 2000 watt samlex pure sine wave power inverter and my 60 amp hour LiFePO4 battery.
I tested it on my 40 amp hour battery, then expanded it to 60 amp hours, a mod I have been sitting on for too long.

My 40ah AMP20 cell battery had just enough power to run the power inverter with the welder on it at full power for a shot time. Problem is the battery had to keep the voltage above 10.5v at the inverter.

[oil pan 4]

Here is my up date on my economic home made tig welder.



This is what it looks like when I use it on stainless steel.



I have less in it than what one would spend on the cheapest made in china imitation dog poo, its reliable and has a top end miller WP-17 torch. Sliding core machines like this typically last until some one steals them to harvest the core out of them or some one takes one to the scrap yard because they think its "obsolete".
So the main two things that kill them are ignorance and drug addiction.

[Elcam84]

How well are the starts on that rig. Without the features that make tigs easier I can see it being a little more challenging to use. I have used the $200 import tig and it's impressive for the price and for most that will use it here and there it's fine and the $400 version has a foot pedal etc. But no ac so no aluminum or at least not much aluminum welds DC.

Not a bad looking weld at all for that machine. The first time I used a flex head torch I thought why do they even make anything else.

[oil pan 4]

I have never used scratch start before this. Always used a miller maxstar 150 and 200 with lift start.
Otherwise its performance is almost identical the $1500 machine on 120v power.
I have AC, I don't know if 60Hz is useable on aluminum, all the AC machines that get used on aluminum produce around 400Hz.

As far as I can tell you really only need the foot controller for aluminum.
I weld a lot of stainless and have never used the foot controller.

[stevehull]

I, for one, am VERY impressed with the weld quality. The picture looks great.

Steve

[Elcam84]

Cool. Great to hear it works that well. Especially on 110v. You don't need the super high HZ for aluminum but it helps. Same with the foot controller but those things are more important for the super thin stuff.

Those old style machines like yours were good machines. My neighbor has a big eutectic tig as that's what he used when he was a welder In a semi trailer shop. Water cooled torch etc. But the transformer had a fire due to the coating on the windings deteriorating. He is going to have a motor reminder look at it and se if it's feasible to rewind. Problem is it takes a forklift to move.

Just never ask me to use an old cracker box. Learned how to weld on one and if you can use it you can use any machine after that. Also learned mig on a miller box with a cobra matic wire feeder. That was bad... Never would keep a steady wire speed.

[oil pan 4]

On the subject of welding aluminum, welding aluminum with DC takes helium which has gotten expensive in recent years and you have to use reverse polarity DC to weld aluminum.
Problem with reverse polarity tig is it puts the vast majority of heat into the welding electrode. The welding electrode gets something like 8 times as much heat running in reverse polarity.
When welding straight polarity the vast majority of the heat goes into the work (80% to 90%).
Mostly balanced organic AC power will not heat up the electrode as much as reverse polarity DC. The electrode might see around 4x the heat as compared to running it straight polarity.
The expensive AC machines can create 400Hz AC power that has 90% of the power on the straight polarity side and 10% on the reverse polarity side.
You have to have at least some reverse polarity to deoxidize the aluminum.

In the past, with welding aluminum you had a choice of using a cheap DC machine with over sized water cooled torch and more pricy helium, or a super expensive AC machine and cheaper argon gas.
In recent years the price of the expensive high frequency AC machines has come way down (but they are still expensive, a few thousand dollars for a good one), the price of helium has gone way up, if you can even get it so almost everyone has gone with more advanced high frequency AC machines that can weld aluminum with cheap plentiful argon.

Now what I cant find any info on is if balanced 60Hz needs argon or helium or a blend, or if it will even work. Since you can weld aluminum with DC+ and helium I don't see why I couldn't make 60Hz AC work unless there is some kind of funky magnetic, hysteresis, eddy current losses going on.

I have 1/8 inch wide Zirconium oxide doped tungsten electrodes that are supposed to be toughest most heat resistant electrodes you can get. Some time soon I will plug the leads into AC put one of those electrodes in my torch put it to aluminum and see what happens.

[jeff5may]

fwiw, I use 100% ARGON on most everything except mild or carbon steel. If you want pretty and clean, TIG is the way to go, and a square wave machine will do anything you throw at it. A buzz box like oil pan has in his pic will do for anything above about 10 gauge, but for thin sheet, you either have to do little stitches or have some crazy skills. But TIG is inherently slower than MIG.

For high-speed welding at the cost of looking super pretty, you can weld aluminum and stainless and such with a MIG machine, even on DC. The wire you choose must have the right trace elements in it to scavenge the oxygen and hydrogen while the puddle is wet. Also, you have to use separate torches. Iron and aluminum make thermite.

With aluminum, a push-pull torch is nice, but a regular torch will work as long as you keep it clean and don't bend the whip too much. Either way, when welding DC you have to speed through the work, and have a big enough power supply to do it. If you go just a tad bit slower than you should, everything will melt like wax. If the power supply won't source enough amps, you can't move fast enough to stay ahead of the heat.

When joining aluminum or stainless with MIG, be prepared for the sugar and smut to appear, pretty much no matter how much shielding gas you use. Don't worry, the stuff wipes right off after your piece cools down.

The new MIG rigs use pulsed power instead of AC or DC "old school" power. Unless you are doing some super-high speed production or using robots, the pulsed mode is not really all that useful or practical. The only exception to this I can think of is doing full-penetration, vertical uphill welds. I would still almost rather stick weld something uphill than use one of the new rigs. The darn things will fry your eyes through your eyelids like an atomic bomb, but boy are they fast if you get them dialed in right!

I used to have a rig like oil pan's, made from an old battery charger/booster. It was used with everything thin with argon and an air-cooled TIG torch. I tried it with a neon transformer to do the easy-start thing, but it wasn't all that useful to me. I ended up just scratch starting with it. I wired up a toggle switch to the torch for on-off control, and had an alligator clip to jump out the rectifier. It worked and worked until my dad and his gang of pirates scrapped it during a barn cleanout.

[oil pan 4]

To eliminate sugaring I use solar flux or if its a pipe I back purge with argon.
Solar flux is fine as long as you don't care what the back side of the weld looks like.

[oil pan 4]

I removed the cord and replaced it with this.


Still working good.


Gas saver nozzle and gas lens.