[Chips O'Toole]

I finally found the steel coupons I prepared this week, and I tried another batch of lap welds. I worked at applying all the suggestions people made last time.

It turned out my amperage problem was due to the way the welder works. When you switch from trigger to pedal, if you don't do it right, the welder stays wherever you had the trigger set. I didn't have problems with it today.

I did a much better job of controlling the arc length and torch angle today. I had some interesting panic-filled moments when the rod got too short, and they tended to cause problems with the beads, but I did not get welds that were as convex as last time. I have to get rod feeding under control.

I am still getting welds that are a bit grey. They seem shinier than they used to be, so I'm wondering if I'm improving. I tried lowering and raising the amperage, and I also shortened the stickout, figuring more gas coverage might make a difference. I don't think it changed anything. I am trying to move fast and avoid overheating the metal.

I learned that the welding table has a duty cycle. If you don't let it rest, you have to worry about melting plastic items you have parked on it. I can see why people like thick tables!

[Oscar]

Remind me again, how are you cleaning your steel coupons?

[Chips O'Toole]

These were soaked in muriatic acid, wire brushed until shiny, and then cleaned with acetone. I can't get cold-rollled or pickled and oiled here.

[Farmwelding]

These were soaked in muriatic acid, wire brushed until shiny, and then cleaned with acetone. I can't get cold-rollled or pickled and oiled here.

So why not just use a grinding wheel of flap disk instead of soaking? Seems like a lot of extra time and then wire brushing just polishes mill scale so try grinding it off next time.

[Oscar]

No wonder they looked weird.

These were soaked in muriatic acid, wire brushed until shiny, and then cleaned with acetone. I can't get cold-rollled or pickled and oiled here.

So why not just use a grinding wheel of flap disk instead of soaking? Seems like a lot of extra time and then wire brushing just polishes mill scale so try grinding it off next time.

Exactly. On real welding projects, you won't be able to soak entire "things" in muriatic acid.

[Chips O'Toole]

The grinding wheel takes a very long time and leaves big ruts in the work, so I thought it was a bad way to train myself to prepare projects I didn't want to chew up. I have a 60-grit Metal Demon flap wheel on a 4-1/2 grinder, but it just polishes the scale. You can run it all day and never break through.

The rotating wire brush I used on these was not applied until all the scale was gone. It was just to knock off anything that formed on the metal after the scale was removed.

Today I used a paint-stripping wheel instead of the wire brush, and I got the metal as shiny as steel can get. I won't use the wire brush any more. I followed with acetone. I'm not sure it made a difference. The only thing that makes the welds shine is moving faster. I got a couple of shiny beads while moving as fast as I could.

The amperage I'm seeing seems to drop off after I've been welding a while. It also seems to be reduced when I restart a bead. The welder manual doesn't explain that. The welder is supposed to shut off to protect itself when the duty cycle is exceeded. I think my ground is okay; it's attached to the side of the table, and I wiggled it to make it bite in. The metal is sitting on the table, which is not rusty or dirty.

When the amps drop off, I slow down automatically, because it takes a long time to form a puddle. I am wondering if this pedal is working correctly. I know I screwed up the amperage in previous efforts, by not letting the welder reset when switching from 4T to 2T, but this time I had it working right.

[Oscar]

24-36 Grit. Not 60. Problem solved. But oh well, it's your time and effort, not mine.

[MinnesotaDave]

Because you don't have consistency yet you're wasting material doing lap joints.

On a flat piece about 1/8" or 3/16" thick, make beads that half overlap until you can make a consistent width and height bead every time.

It's just my opinion, but it's how I start every stick and tig student.

It's called padding and it's how you build up worn surfaces.

A lot of people think it's a waste of time, because they want to build something, but it's the cheapest practice you can do.

(Picture from the stick section of my textbook)

image.jpg (43.18 KiB) Viewed 1169 times

[Chips O'Toole]

I will work on the padding exercise. It sounds like just what I need.

I found out one cause of TIG welder amperage problems. It turns out that when your pedal hits an obstruction (such as part of your welding table) on the way down, it will result in lower output at the electrode.

I had my pedal under the table, and as I used it, it moved over by one of the lower rails of the table. I was only pushing it down part of the way, because the rail was under it!

I was checking connections and thinking about taking the pedal apart. It was driving me crazy.

It looks like speed and my mysterious amperage problem are the causes of my grey welds.

[Chips O'Toole]

It seems like new complications keep popping up. It looks like a welder's duty cycle doesn't apply to the torch. Is that correct?

I started using a timer to make sure I don't go longer than 6 minutes, and I set it for 4 minutes between welds, but the torch is still hot when I start up again. I'm nowhere near the welder's maximum amperage.

[LtBadd]

It seems like new complications keep popping up. It looks like a welder's duty cycle doesn't apply to the torch. Is that correct?

Correct

I started using a timer to make sure I don't go longer than 6 minutes, and I set it for 4 minutes between welds, but the torch is still hot when I start up again. I'm nowhere near the welder's maximum amperage.

So remind me, you're using an air cooled torch?

I bought some A36 (hot rolled) flat stock to try and duplicate your situation, hope to post something soon

[MinnesotaDave]

It seems like new complications keep popping up. It looks like a welder's duty cycle doesn't apply to the torch. Is that correct?

I started using a timer to make sure I don't go longer than 6 minutes, and I set it for 4 minutes between welds, but the torch is still hot when I start up again. I'm nowhere near the welder's maximum amperage.

Before I started using water cooled torch I would hang the air cooled torch in front of the welder cooling fan (huge fan on my machine).

A regular fan works too.

I cooked (ruined) a few wp-26 torches on AC current before I switched to water cooled.

If you are using a 9 series torch, it'll over heat fast.
17 or 26 series are much better for heat.

[Chips O'Toole]

For God's sake, don't spend money on steel to fix my issues. I think I'm just slow, with bad technique. And obstructing the pedal didn't help.

I have the air-cooled 17 torch that came with the welder. I just assumed the torch's duty cycle was equal to or greater than the welder's. Guess I can forget about that. I haven't melted the torch or anything, but it does seem like it gets too hot to continue using, well within the welder's duty cycle.

People complained about the torch the AlphaTIG originally came with. I don't know if I have that torch, or if they fixed the torch by the time I got my machine (March 2017).

It's not a problem. Just new information to keep in mind.

I think welding practice is harder on everything, because you're doing as much as you can, instead of setting up a typical job and finishing in a few minutes.

[MinnesotaDave]

I think welding practice is harder on everything, because you're doing as much as you can, instead of setting up a typical job and finishing in a few minutes.

Ha! Define "typical" and "a few minutes"

[Oscar]

Keep in mind that just because a torch is hot doesn't mean you have exceeded it's duty cycle. But one thing you do have to worry about is over-heating the power cable if it is a 1pc power cable. It's usually only a problem when doing AC welding, but even DC welding can get it very toasty.

[MarkL]

I just assumed the torch's duty cycle was equal to or greater than the welder's.

I'm only familiar with Lincoln torches, but they specify their duty cycle. If you look at this product brochure and search for the word duty, you'll find the duty cycles for each of the torches in terms of 60% at some current. If you can figure out who makes your torch, you can probably find the same information from the manufacturer. With a 17 torch I would guess your torch has a higher duty cycle than your welder in terms of doing damage to the torch, but you might need a heavier glove on your right hand to be able to use the torch at it's rated duty cycle. You might also try bumping your pedal a few cycles while your welder is resting, that will help cool the torch.

[Chips O'Toole]

I don't actually know how to tell when a torch is too hot. I assume the first warning sign isn't a molten or flaming torch.

[Poland308]

A 17 air cooled torch is rated for use at 150 amps but even at 130 -150 amps I've melted down a few of them. One melted enough that the brass inserts became loose in the body. I've also burnt up one at the threaded connections. Both times I noticed a stuttering arc. Oh and it was kinda hot to the touch.

[Otto Nobedder]

For God's sake, don't spend money on steel to fix my issues...

LOL! I can assure you of two things.

First, Richard will most certainly get his own use out of this steel.

Second, he and we will likely learn something in the process. Even those of us who've been at this 30+ years like to learn something every day. If I'm not learning, it means I no longer find it interesting, and it's time to move on to something else. In my case, that would likely be the grave.

Steve