250EX issue

My 250EX won't start a puddle in ac mode. Just heats up the metal until it warps and makes a hole. Material thickness doesn't matter. Frequency, argon, balance and amps don't matter. Machine grounded to its own additional ground. Not grounding issue. Noisey Arc in ac mode. DC mode quiet arc and runs nice bead. Not tungsten or tungsten distance issue. Machine only in use a little over a year and sparingly. Need to talk to a tech or someone who had the same issue. No guessing please. Need technical expert. Tired of wasting argon and have work to do. Thx

The secondary chassis ground bolt on the rear of the machine has nothing to do with any of it and can not. The chassis is already grounded through the green wire of the power cord.
You can reach tech support at 877 755 9353 ext. 207

An AC arc will make a noise at the frequency you have set. That is normal.
That is just how aluminum welds. It takes a hell of a lot more skill to weld than steel. What you have is an oxide layer over the puddle. The problem is that aluminum oxide melts at 3,762°F, while the melting point of the aluminum underneath is only 1,221°F. For starters, be sure to remove as much of the oxides as you can, either by grinding or brushing with a stainless wire brush. New oxides will form almost immediately, but it will be a thin layer. The cleaning action of the AC arc will help to punch through those oxides, but you will not see the kind of puddle that you do with steel. Often you can help things get started when you add filler by punching through the skin over the puddle with the filler rod. Some people pick it up pretty quickly, while others struggle for quite some time trying on their own. Maybe find someone local that can demonstrate for you, in person.

It doesn't matter if I brush it or grind it Shiny first, I should of stated that. The machine use to easily start a Shiny puddle on aluminum. I understand frequency changes the pitch of the noise but this is unsteadiness or something. I believe my machine is having an issue switching to ac. I thought tech support was on here but I'll call. Thx!

If it is making the buzz, and your puddle is falling through it is making AC. It's likely that there is an environmental issue or a metal issue. Make sure your work clamp is in the positive (+) and the torch is in the negative (-).

Yeah,

Without you posting your exact settings used, guessing is to be expected.

But, absent a machine problem, you undoubtedly only have a setting problem.

I'll guess that your AC balance is too low. Set it to 40% AC cleaning action and you'll probably get your aluminum starting back. And like Rambozo suggested, just dwelling over the piece with the torch is probably creating your problem, and some agitation may help.

Please let us all hear how it goes or if it was just a matter of settings.

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Originally Posted by Blaze

My 250EX won't start a puddle in ac mode. Just heats up the metal until it warps and makes a hole. Material thickness doesn't matter. Frequency, argon, balance and amps don't matter. Machine grounded to its own additional ground. Not grounding issue. Noisey Arc in ac mode. DC mode quiet arc and runs nice bead. Not tungsten or tungsten distance issue. Machine only in use a little over a year and sparingly. Need to talk to a tech or someone who had the same issue. No guessing please. Need technical expert. Tired of wasting argon and have work to do. Thx

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Ok, you came across like you had never welded aluminum before. If things used to be fine and now it's not, then you have to figure out what changed. The fact that you have an arc that is hot enough to melt the metal is about all the power supply really does. Things like keeping the puddle shiny is all about shielding gas, and contamination. There isn't really any machine setting or fault that can cause the puddle to be contaminated. While it won't be as easy as with the right settings, you can pretty much get a good weld with any settings, from 30% to 70% balance and from 30Hz to 500Hz. Plenty of welds have been done with machines that don't even have those controls. Without knowing the specifics there will always be a lot of guessing. Like for all I know you are trying to weld 2011, 6262 or 7075 aluminum. If the machine is buzzing it is very likely that you are making AC, but I suppose you might just be making pulsed DC. That could have a similar sound, but would weld aluminum like DC. Apart from test gear, I can't think of any great way for you to test that. Maybe by looking for cleaning action and swapping the leads and checking again? But after hearing so many people here that have so many problems with aluminum that traces back to a bad tank of gas, that would be the first thing I would check. Full description of what you are doing and with what settings, along with some photos would help the most. If the sound is not like it used to be, maybe grab a video just to get the sound if nothing else.

Just a thought. What would cause the machine not to clean anymore. What makes the balance work correctly?

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Originally Posted by Blaze

Just a thought. What would cause the machine not to clean anymore. What makes the balance work correctly?

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That is what I was talking about in the last post. Because of the way inverters usually work, there are separate parts that handle each portion of the waveform. The cleaning is from the DCEP portion and the penetration is from the DCEN portion. If you machine is only producing DCEN you would get no cleaning. But you might still get a buzzing noise if the DC was being turned on and off at the normal AC frequency. I'm not sure if it would even sustain an arc without continuous HF in that situation. But as I said, apart from putting the machine on a scope, I'm not sure there is an easy way for you to test that.
One thing you can do is setup a 1/16" tungsten at 100 amps AC and try to run a bead on something thick. Start with the balance control at 30%, then chance the balance to 70% and see if your tungsten melts down. If it does, you are getting AC, if not you have some kind of fault. Or if the tungsten melts down at 30% but not at 70% then your running reversed.
Cleaning also requires argon around the arc, you won't see any frosting, if the gas coverage is poor or has air in that area.

The thing is, most of the machine faults are not subtle things, but usually total failures of one kind or another. These are high powered circuits and even if something minor goes wrong, with that much current it usually lets the smoke out of something and you are dead in the water.

I am assuming you have checked welding steel with DCEN and it's all good? How about stick welding on DCEP, everything look good?

Start an arc in AC then increase the arc length to about an inch. If it crackles like a taser you've got AC.
Does the arc sound change with frequency adjustment ?
If you hold an arc for a while on the same spot at 30 amps do you see any cleaning action at all ?

1/8 wall aluminum tube
First picture- 100 amps 35% balance
Second pic- 30 amps 35% balance
Third pic- 200 amps 35%
Fifth pic- 100 amps 35% and moving
Forth pic- tungsten after changing ac from 35 to 60/70% balance. Started as a pointed tungsten
Sixth pic- 100 amps 40% balance bottom and increased balance as you move up.
Tried 30 amps and then pulling tungsten away from metal as suggested. No crackle, Arc just lengthened. I did notice as I tried to move the Arc it stuck behind, kinda wouldn't move with torch and kinda sparkled instead of nice Arc like when welding dc. Started wondering if the hf start wasn't shutting off after the Arc initiated or it was staying on because the Arc won't initiate. Thank you all for your assistance. Still fustrated this is my second welder to go this year. My I mig 250 broke earlier this year.

Don't see any cleaning action (cathodic etching ) at all. Looks a lot like poor gas coverage, except the tungsten is bright and shiny. Since the tungsten balled, you have to be getting the DCEP part of the wave. Sounds like the balance control is working as well. Once again it sure seems to point to a gas contamination, or air leak or something. That's what I would check as a first step. Swap to a known good bottle of pure argon, and make sure there are no leaks in the hoses or fittings. I would also advise a slightly large cup size for aluminum. It might just be the closeup, but that looks like a #4. I would go with a minimum of a #6 for better cleaning action.

Must be in the machine if at all. I checked everything out last bottle. Gas company hasn't had any other complaints. I can feel the gas on my face just fine so I know it's flowing through. I'll open machine tonight. Ugh.

Doesn't matter that the gas company has no complaints. All it takes is one guy not evacuating a bottle before filling it because it was thought to be pure argon. You can weld steel with pretty dirty argon, but aluminum will not tolerate that. I've lost track of how many people here were sure they had good gas, until they got a new bottle. It would be nice if there was an easy test for argon purity, but I don't know of any. Any good gas supplier will swap a suspect bottle no problem.
Also gas coming out of the torch doesn't mean that air isn't being sucked in somewhere. One person here had a bad o-ring on a torch that gave him fits until he figured out it wasn't sealing on the torch body, because it was too small.

Hey, Blaze,

Please post a photo of the face of your machine that shows all the knob settings and the cables plugged into it.

And then, how about a bead on plate, mild steel, as well, too, please.

And, is your gas 100% Argon, or is it C25?

The last bottle I had ran like crap to. This is a new one. I'll recheck the torch and line to machine. You mean O ring on torch back cap? However my machine ran fine before.

Ok. I sprayed soapy water all over the supply hose, regulator and house from machine to torch and torch and no bubbles formed. With argon flowing. I unplugged my welder and turned it on. How long before I can safely open it? And once open it how do I flow the gas to check for leaks or does the gas flow to a switch connect right behind the front panel and free flows to that point?

Here are pics of the front of my 250EX. No pulse is being used. Hf start. Various frq settings. Tried 60 to 200.

I decided to try lift start tig. Couldn't get it to work but after multiple tries it finally started working. Changed back to hf start and the machine started welding good again. The hf still stutters sometimes but is now changing over to a steady Arc. I don't know what makes the machine change from hf start to a welding Arc but it finally is switching. Anyone know how that works? Also what role does stick out length perform during ac welding or any welding. Really would like to know how the hf to welding Arc switching works. So happy but it still stutters once in awhile. Do I need to clean something inside or you think a part is going bad? Thanks Rambozo and everyone!

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Originally Posted by Blaze

Ok. I sprayed soapy water all over the supply hose, regulator and house from machine to torch and torch and no bubbles formed. With argon flowing. I unplugged my welder and turned it on. How long before I can safely open it? And once open it how do I flow the gas to check for leaks or does the gas flow to a switch connect right behind the front panel and free flows to that point?

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The Everlast guys typically say to give it 15-30 minutes. Still it's always a good idea to watch out for charged caps in equipment like this.

The last bottle was unable to weld aluminum, or just did it badly?

Since you mentioned that you thought the HF might be on all the time, you could try using lift start to see if it will even hold an arc without HF. That might help support figure out what you have going on, unless you just want to send the machine in.

Typically to find leaks, you will have to block the front of the gas cup so there is some pressure in the hose. The easy way is to watch your flowmeter when the end of the torch is plugged. With the solenoid open, the flow should drop to zero. If it doesn't, you have a leak.

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Originally Posted by Blaze

I decided to try lift start tig. Couldn't get it to work but after multiple tries it finally started working. Changed back to hf start and the machine started welding good again. The hf still stutters sometimes but is now changing over to a steady Arc. I don't know what makes the machine change from hf start to a welding Arc but it finally is switching. Anyone know how that works? Also what role does stick out length perform during ac welding or any welding. Really would like to know how the hf to welding Arc switching works. So happy but it still stutters once in awhile. Do I need to clean something inside or you think a part is going bad? Thanks Rambozo and everyone!

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Looks like I took too long to suggest that. ;)

Glad to hear you are up and running, again.

I still wonder about the positive half of the wave. The HF runs until it detects the main arc is stable. I don't know the exact circuit and if it checks both positive and negative portions. Older machines will let you run the HF continuously, so it should have welded even if the HF was stuck on. My guess is that there was no positive side of the main arc or it was intermittent or something. You would have to see the output on a scope to be sure. I would keep an eye on it and let tech support know about this, anyway.

If yours is a points machine ( they changed a few times) , it never hurts to clean and adjust the HF points. Good time to blow out any dust inside, too.
Because of the dirty shop environment, it often helps to flip all the switches and turn all the knobs from time to time to help clean contacts and such. Especially if the machine isn't used all the time.

Thank you! I'll contact tech support tomorrow. Ok. I'll still open the machine and clean it out.