[JoePeeple]

Hi from a loooong time lurker

Some assistance would be much appreciated.

When I Tig weld on either AC or DC, the HF start can be intermittent. Sometimes the arc initiates perfectly, other times not at all. In the instances when the arc does not strike, I have found that letting off the pedal completely, then touching the tungsten to the workpiece, lifting the tungsten from the workpeice, then stepping on the pedal again gets the arc to strike. It is almost as if I need to ground the tungsten before the arc will initiate. In the instances that the arc does not initiate, I can still hear the HF buzzing from inside the machine.
My question is, do I open the HF points gap, or close the gap to make the arc strike more reliable? Currently the HF gap is 0.7mm (0.027")
The machine is a 200Amp AC/DC with pulse capability chinese tig welder (sadly this was all I could afford )

Another unrelated question is regarding filler rods. In my little town, we dont have any dedicated Welding Supply stores, only hardware and engineering type suppliers. The only filler rods I am able to get hold of are 316L fillers for my mild steel and stainless jobs, and 4043 for my Alu projects. Just to be clear I am only a hobby welder, doing small jobs for pocket money. Are these rods OK for general work? Alu work is mainly boat propeller repairs, and mild steel work is pretty much anything that comes up.
Thanks for taking the time to read this, and to offer assistance
Chris

[cj737]

Living in South Africa can suck for getting "supplies". And shipping rates are whacked! The 4043 is fine for ally work, though 5356 would be better for your prop repairs. The 316 for mild steel is questionable, I guess it really depends upon the type of steel work. I would not want to use it (316) for anything where strength is important. Can you get some 7018 Stick rods (3/32") and use them for your mild steel work? your welder should be able to Stick and TIG.

I occasionally have the same HF issue on AC with mine. I find that it tends to be due to my tungsten being a tad contaminated from ally work. Or, stomp the pedal to initiate the arc with more amps. It could be that your welder requires more amps to stabilize that arc and get it going.

[JoePeeple]

Hi cj737

Thanks for the reply. OK, I will try the more "aggressive" approach on the arc start, to see if it works. Now that you mention it, this problem does seem to occur if the tungsten has a bit of surface mill scale contamination on it from mild steel work. Probably the same holds true for the Alu work, maybe a bit of crud spat onto the tungsten is stopping the arc. I will keep an eye on this.
I reckon I should be able get my hands on some 3/32" 7018 stick rods for mild steel work (the welder does indeed do Stick and Tig) I prefer Tig welding though, it certainly doesn't make my workshop as dirty as Stick welding does I will also see if the local engineering shop will order in some 5356 filler rods. Trying to order this kind of thing online and bringing it in for myself is pretty expensive, and the lead times are looong.
Thanks for the suggestions
Chris

[Louie1961]

I have the same problem on my Syncrowave. Its probably not the machine. I have heard lots of other folks complain about it. It seems to be a fairly common issue across a number of manufacturers and across both transformer machines and inverters. I just live with it personally. I routinely swipe the tungsten to the metal to be welded (as a habit really) before initiating the arc.

[Lightning]

I have a Sync 250 and have the same experience to report as Louie above. Not sure what causes it, the moon phase, the tide stage, the alignment of the planets or the activity of the sun spots, but I also ground the tungsten before starting and tell myself that makes it more reliable.

FWIW, the manual for the Miller 330A/BP says that you can make the HF starting more reliable by opening up the spark gap. IIRC, they recommend a max gap of .013"

[noddybrian]

Most of the import machines I've used had this arc start issue & as others have said grounding the tungsten & retrying usually solves it ( I don't understand why - I have one that will maintain over an inch of arc length on HF but still can mess about initially ! no idea why )- though AC is always worse - having long leads wrapped up or tangled seems to make it worse so it's worth having a look & keep the leads as straight & tidy as possible - a few machines actually have settings in a sub menu relating to arc start / HF - I think the Dynasty does - you can give it more oomph at the expense of higher initial currents if your not welding on very thin material - I've cleaned & moved a few points gaps often with no manual for guidance & they usually seem to work better with larger gaps - I think the book settings from makers is more to do with interference regulations than actual arc starting performance - it's always worth cleaning & moving them a bit by trial & error - does'nt seem to hurt anything & often improves it.

[cj737]

I just realized, I used to have this issue on Ally, but I haven't in months. The only thing I switched is my tungsten from using a Green to a Blue. Are you by chance also using 100% tungsten?

[JoePeeple]

I have the same problem on my Syncrowave. Its probably not the machine. I have heard lots of other folks complain about it. It seems to be a fairly common issue across a number of manufacturers and across both transformer machines and inverters. I just live with it personally. I routinely swipe the tungsten to the metal to be welded (as a habit really) before initiating the arc.

Hi Louie1961

Thanks for the input, I will keep on swiping

[JoePeeple]

I have a Sync 250 and have the same experience to report as Louie above. Not sure what causes it, the moon phase, the tide stage, the alignment of the planets or the activity of the sun spots, but I also ground the tungsten before starting and tell myself that makes it more reliable.

FWIW, the manual for the Miller 330A/BP says that you can make the HF starting more reliable by opening up the spark gap. IIRC, they recommend a max gap of .013"

Hey Lightning

Thanks for the info regarding spark gap. The gap on my machine is already twice that which Miller recommends, however I do realise that different machines are designed to make use of different spark gaps.

[JoePeeple]

Most of the import machines I've used had this arc start issue & as others have said grounding the tungsten & retrying usually solves it ( I don't understand why - I have one that will maintain over an inch of arc length on HF but still can mess about initially ! no idea why )- though AC is always worse - having long leads wrapped up or tangled seems to make it worse so it's worth having a look & keep the leads as straight & tidy as possible - a few machines actually have settings in a sub menu relating to arc start / HF - I think the Dynasty does - you can give it more oomph at the expense of higher initial currents if your not welding on very thin material - I've cleaned & moved a few points gaps often with no manual for guidance & they usually seem to work better with larger gaps - I think the book settings from makers is more to do with interference regulations than actual arc starting performance - it's always worth cleaning & moving them a bit by trial & error - does'nt seem to hurt anything & often improves it.

Hi noddybrian

Thanks for the good tips, I will try to ensure that the leads don't add to the problem/issue.
My next trick is going to be to do a bit of trial and error spark gap adjustment, to see what works and what doesn't. I will report back on my results

[JoePeeple]

I just realized, I used to have this issue on Ally, but I haven't in months. The only thing I switched is my tungsten from using a Green to a Blue. Are you by chance also using 100% tungsten?

Hi cj737
I currently use a 3/32" 2% Thoriated Tungsten for steel work, and a 3/32" 0.8% Zirconated Tungsten for Alu work.
I found that the Thoriated Tungsten did not hold up well on AC, and instead of balling up the tip, it would make weird cauliflower shapes on the tip. The Zirconated Tungsten tip balls up nicely and seems to hold up better on AC (on my machine anyway)

[cj737]

I currently use a 3/32" 2% Thoriated Tungsten for steel work, and a 3/32" 0.8% Zirconated Tungsten for Alu work.
I found that the Thoriated Tungsten did not hold up well on AC, and instead of balling up the tip, it would make weird cauliflower shapes on the tip. The Zirconated Tungsten tip balls up nicely and seems to hold up better on AC (on my machine anyway)

Yeah, you don't want a Thoriated tungsten on AC, it will just tear the tip into bits. I've never used Zirconated, so I have no opinion on that. If your box is an inverter type, you might give the Lanthanated a go and see if it makes a difference. Then again, the issue you're having isn't really the end of the day, is it? And you aren't the only person on Earth who suffers from it now and again-

[rick9345]

4% Thoriated
DGP CRYO-T
Before one yells radiation look up Thorium