Powerarc 161 STH settings

[TNDoug]

I'm having a heck of a time tig welding a new stainless exhaust sytem. My settings: 15 cfh,( varied between 10 and 20), 2T, pedal, high frequency start, 8 seconds post flow, 1 sec preflow. I've gone from 40 to 80 amps and everything in between. I'm using 1/16" thoriated red tungsten, 308l 1/16" filler rod. I've used #4 to #8 cups. I'm having burn through ( amps too high ?), poor penetration ( amps too low?), and it's a mess. This is a brand new machine. Any suggestions other than send the tig welder back?

[christian]

Yeah,

If you've never TIG welded stainless before, and especially if you've never TIG welded before, it's a bit tricky.

I designed and welded a custom stainless steel exhaust system for a Mazda truck, five or more years ago, when I was still pretty new to TIG and even newer to TIG welding stainless steel. And I still haven't done much stainless work beyond that exhaust system.

But, I made sure the system turned out quite nice, with a seemingly seamless look to it, as the welding beads were not too pretty. And I know now how naive I was at the time about welding stainless.

So, of course, don't blame the machine.

In the meanwhile, post some pics. They can tell a lot.

[TNDoug]

Just an added note: stick out: flush, 1/4", 1/2". Torch on negative, ground lead on positive. Looking for some guidance on set up. Thanks.

[christian]

Yeah,

Try settling on a medium-large cup size of #8, with about 15 CFH Argon, i.e., forget about getting rainbow color heat signatures, as you probably don’t plan to do any Argon back-purging anyway (I didn’t). .5 sec of pre-flow is plenty, and 5 sec of post-flow is pretty good for such low amps, but some ss pros seem to use more post-flow. Although, like me, I’m guessing that you’re not going for ss exhaust weld porn on your first go, i.e., is it for your own vehicle, like mine was?

Your stick-out could be around 3/8” to see your arc well and keep the tungsten fairly uncontaminated. Although, regrinding a tungsten pretty often with early TIG projects is something I recommend and have done, too.

1/16” filler or 3/32” are both fine. 1/16” takes more dabbing proficiency and speed than 3/32”, though, to keep from burning through.

That muffler I used was a MagnaFlow, and had a wall thickness that matched the ss tubing pretty well. But the resonator has a very thin wall thickness and an imperfect fit, so I had to make a wider ramp-up weave pass, that I later ground out to get the seamless look.

So, show us some of the materials you’re using. You know tubing thickness, which muffler, any resonator, etc.

Let’s see some pics…

[TNDoug]

I own a full on restoration shop specializing in classic cars from the 30's to the 80's. I've been restoring cars for 40 plus years. This exhaust is for a 280 ZX turbo with 3 inch stainless exhaust. We just bought this tig machine for the shop. We normally don't build exhaust systems so it's a new one for us. I did notice that the manual states "2T, 4T, pedal". We have 2T and pedal lit up. Should just be one, not both. Photos to follow.

[christian]

Yeah,

I didn't use a pedal on that DC-only TIG welding unit I had at that time (I didn't have my Everlast 210EXT at that time, or yet).

So, you don?t really need a pedal on DC TIG, and can run it kind of like MIG or Stick.

Yeah, I believe 2T and Pedal can both be lit up, and may be useful that way for some amptrol devices. But just cycle the button to 2T alone for a MIG or Stick-like action. You'll still get the post-flow.

So, you are doing it 2T and no Pedal then, right? I mean, that's a good way too. Don't bother with the Pedal if it's something new for you guys. TIG is a two-handed process, so filling with your other hand will keep you busy enough.

Otherwise, I'd structure the system so that all the welding can be done on the bench. That's what I did.

[TNDoug]

We have a pedal and the torch upgrade. This system has a 3" Magnaflow muffler, stainless flex pipe, 3 exhaust band clamps for easy removal and is 3" from front to back over the axle and a 3" to 4" end cap. We tacked the system for fit up on the car and now we're trying to get a real nice look on the welds. My grandsons are inheriting the shop and want to build high performance engines (too new for me). We build engines and transmissions now and have a full paint shop. They learn quick and are "tech" savvy (I'm not).

[christian]

Yeah,

Nice looking welds will most likely happen on the bench, with a bit bigger cup, more Argon flow, some back-purging, along with a lot of stainless TIG welding experience.

Or, like I did, as a newbie, none of that, and just some flap disc action to get a seamless look to hide the unflattering bead appearance. Ha, ha, ha... I mean, I could have brushed-out those beads with a wire wheel to make them look OK, but I knew I'd probably want the nicer seamless look.

But, it would be nice to see a pic of the layout, fit-up, and tack-up, i.e., how many actual welded joints there'll be.

Otherwise, that 161STH seems to have a Pulse feature, which may help control your heat input, especially with no Pedal. So, try some practice pieces with Pulse.

We have a pedal and the torch upgrade. This system has a 3" Magnaflow muffler, stainless flex pipe, 3 exhaust band clamps for easy removal and is 3" from front to back over the axle and a 3" to 4" end cap. We tacked the system for fit up on the car and now we're trying to get a real nice look on the welds. My grandsons are inheriting the shop and want to build high performance engines (too new for me). We build engines and transmissions now and have a full paint shop. They learn quick and are "tech" savvy (I'm not).

[TNDoug]

We use a mig welder a lot in the shop for body work. We're set up to back purge so we'll see how it goes. The "boys" have better hand/eye co-ordination so they'll figure it out. Thanks for the input, sounds like we're headed in the right direction.

[performance]

Are you using pure argon?

[christian]

Gee,

Here's a new Everlast video from their YouTube Channel which happens to be on stainless exhaust TIG welding, and how much difference back-purging makes.

.035 filler, too.

[TNDoug]

Yep. Pure Argon.

[TNDoug]

You said you didn't back purge, now you're for it? For the record, I said I back purge. I've already seen this video. You don't seem to be offering any new information. Thanks anyway.

[christian]

Yeah,

I said I was naive back then.

So, I do now recommend back-purging, especially if it?s for a commercial customer.

I might be able to offer some better or more helpful input, if you?d provide some feedback in the form of a pic of the system layout, the fit-up, tack-up, how many welded seams, etc?

A pic can tell a lot.

Are you considering Pulse, then?

[christian]

So,

How'd that system turn out?

Let's see some pice!

Or, what really worked or didn't work for you?

[performance]

Put your clamp direct to what you are welding. Set your flow at 20. Make sure your torch is in the negative. Do you have pictures of the weld and the tungsten after use?

[jeb the reb]

I'm having a heck of a time tig welding a new stainless exhaust sytem. My settings: 15 cfh,( varied between 10 and 20), 2T, pedal, high frequency start, 8 seconds post flow, 1 sec preflow. I've gone from 40 to 80 amps and everything in between. I'm using 1/16" thoriated red tungsten, 308l 1/16" filler rod. I've used #4 to #8 cups. I'm having burn through ( amps too high ?), poor penetration ( amps too low?), and it's a mess. This is a brand new machine. Any suggestions other than send the tig welder back?

Step down to an .045 or even a .035 Dia filler material. I find when welding stainless tube that 80 amps is a little hot. I use the 1 amp per .001 rule and with stainless 60 amps can be too hot for making square butt welds. Make sure all your fits are as square cut and completed butted up as possible. NO GAPS.

[christian]

Here's a newly uploaded video to the Everlast YouTube Channel that I noticed.

It's more about stainless steel TIG welding.

It's what I'm watching right now.