Welding Tips and Tricks

I mention welding 1mm thick stainless and immediately people tell me to practice without pulsing, using foot pedals (I don't have one).

Why is everyone so down on pulse welding? Without foot pedal I cannot adjust amperage on the fly, and so by the time I end the weld, either I'm getting no puddle, or by the time I get a puddle to get a filler rod in, the steel is looking like it came out of a blacksmith forge.

Pulse and cold welding allows me to not get that. Instant puddle, good weld (as much as my unsteady hand can muster), and little to no HAZ. What's not to like?

Is pulse cheating?

You need to develop actual skills of managing heat, puddle size, and filler introduction. Pulse is very useful ONCE you learn how to crawl, then walk. Why teach someone to run on a treadmill when they can't manage a hill?

You should also avoid trying to learn to weld stainless on 1mm scrap coupons. Heat management is v ery, very tricky with stainless and your persistence to avoid using larger cups and adequate argon coverage will make your time basically a waste.

But do as you please.

I live somewhere with very narrow stairs, 5 floors up without elevator. A 125 CF (40 liter) tank of gas weights about 120 pounds, and is quite long. I cannot get that up the stairs at all and the gas guy isn't helping me with this either. And forget 250CF cylinders, it weights even more. Remember I gotta get it down the stairs by myself when it comes time to exchange them. What's worse about the smaller cylinder is they are filling it by transferring it from a larger cylinder, meaning they're filled to maybe 1500 psi if I am lucky. I'm asking the gas guy to just bring me a cylinder for exchange, but he said that he doesn't keep small cylinders around so he will have to dig around. The larger cylinder is also too long to be carried up the stairs, because it's too narrow.

So no, until I live somewhere on the first floor, or with elevators, I cannot use a very large cup, because it means my 40CF cylinder will run out INSTANTLY if I use a #16 cup.

And I cannot find any 3mm thick stainless steel coupons at all. Most the scrap pieces are all 1-1.5mm thick, 2mm if I am lucky. I'm also paying dearly for them.

Most scrap yards are not going to sell me anything, if they do, they will not have anything thicker than 1mm. Fact is most stainless items found in everyday life is not going to exceed about 1mm in thickness, so why learn on something you very rarely encounter? Also honestly, if I'm encountering very thick stainless, it's going to be stick or MIG welded. At least stick welding do not consume gas.

Just so you know, I very rarely seen filler wires used on stainless in Taiwan, not even fully welded. Most are just tacked with 1/2" long fillets, all fusion welded, then electropolished.

These welder has "cold weld" settings precisely for these thin pieces, traditional TIG could never do them properly. They're nice to demonstrate skill, but beyond that is not used at all.

I'll get some mild steel coupons in thicker pieces when I come across shops selling mild steel, but even for mild steel they rarely exceed 3mm in thickness as well.

I've paid people to TIG stuff I goofed off on while machining. It was medium carbon steel (1045). His weld is nowhere shiny but it works. I've never seen a shiny mild steel weld honestly, don't think they are meant to be.

Your exposure to stainless in the world is very limited. Thick stainless (Sch 10, 20 etc) and plate is very common. You assume a great deal from a limited knowledge position. Your prior statement (other thread re: oxidation ) about your welds being nearly as good as the guy from PAT is amusing. You’re learning; great. But your welds thus far are not even close to an experienced welder. It is a skill developed over years. You’re a few weeks into it. There are no shortcuts. No with TiG, MIg, or Stick.

Equipment won’t shorten the learning curve, but it will help you learn. You don’t need a #16 cup, but you need at least a #6, probably a #8 to make decent quality stainless welds.

If you’re welding 1mm sheet, then I’d be running about 28-30 amps autogenously, 35-40 if using filler and the filler would be 0.045. That would allow the filler to help chill the puddle and I could move along without cooking the base material. All aspects of experience that you will learn in the future. 100 amps on pulse would require flying for a travel speed and that will result in very inconsistent toes and beads.

If you can only practice on 1mm scrap, then skip the filler altogether. Or, buy a few coupons of 3.2mm, about 50x200 and pad beads, do T joints and lap joints. Then you can reuse the same piece to lay multiple passes and get some experience.

taiwanluthiers wrote: ↑Wed Jan 03, 2024 2:22 pm I mention welding 1mm thick stainless and immediately people tell me to practice without pulsing, using foot pedals (I don't have one).

Why is everyone so down on pulse welding? Without foot pedal I cannot adjust amperage on the fly, and so by the time I end the weld, either I'm getting no puddle, or by the time I get a puddle to get a filler rod in, the steel is looking like it came out of a blacksmith forge.

Pulse and cold welding allows me to not get that. Instant puddle, good weld (as much as my unsteady hand can muster), and little to no HAZ. What's not to like?

Is pulse cheating?

pulse welding is fantastic.

however the reason i say not to use pulse is your NOT trying to learn how to weld thin metal, your trying to learn how to weld.
need to learn the basics before the fancy stuff. things like pulse add complication. is that failure because of your pulse settings or because of you ?
keep it simple so you can tell when its you making the mistake not something else.
this is also why you start with good known gear and settings. its why i try to get you away from adjusting gas. as long as its working good enough its fine.

"cold welding" is a gimmick in crappy welders. never seen it on a good welder or even middle of the road welders.
the reason is that there is no penetration.
the video you mention in the other thread is using what jody calls "blast tacks". quick hot tacks that are used to hold parts together before being welded over.
its not how to weld thin material, those welds will break.

learn the basics first. we have all been where you are now.

I got some 1mm filler on the way. That's the smallest I can get, any smaller and it will be MIG wires which is 0.8mm.

The 2mm filler is obviously only good for 3mm thick SS plates. I can get them, if I pay dearly for them. They really want a lot of money for it.

Those 1mm and 1.5mm steel I got from a shop that makes stainless kitchen fixtures, so they don't have any 3mm scraps to sell me. I'll need to find some other factories dealing in thicker stainless.

I could weld mild steel but then there's no challenge in it. Almost no mild steel welds I've seen are shiny.

Mild steel welds usually won’t be shiny because the base metal is part of the weld. Shiny only matters for stainless nd titanium. Learn to weld first, worry about appearances and Instagram beauty later. You have ample challenges to conquer with your skills before you ever consider how “pretty” your welds are.

Pad beads on plate. Focus on consistency of the bead, wetted toes, equal spacing. If your base metal is super clean, your welds will be too. Perhaps not shiny, but clean and light grey.

I tried on mild steel, it distorted even though it was thick. I'm not sure if it's because too hot or something. The HAZ was HUGE though, like easily over 3x the size of the gas lens. I mean probably because mild steel conducts heat better than stainless. I've also tried aluminum welding and I've found it to be the easiest to do so far, just that it turns the tungsten to shit and the torch gets HOT after a short time because of the current needed and the cleaning cycle being hard on the torch. I guess this is why some people go with WP20 or other water cooled torch. So far only welding aluminum blocks, it was the only scrap I can get (for free) from my friend because he mainly does CNC machining, and so scraps will be blocks, not sheet metal. I've found I needed to really jam the filler rod into it when welding aluminum, otherwise it wants to melt before it hits the puddle (and all hell breaks loose if this happens, the ball of molten filler rod ends up screwing with the arc), and that the arc length needed to be fairly long or else it will suck molten aluminum into the tungsten, contaminating it.

What you are describing with the aluminum blocks is a lack of amperage from your machine to properly weld the thickness of those scraps. Aluminum takes way more heat to get a puddle, then you can reduce the heat while laying beads.

The exterior of aluminum is covered by an oxide layer that melts around 3500+ degrees. The interior melts around 700. So you need to break the oxide layer then you can lay off the amps. Plus, aluminum retains the heat (soaks it up) so as you weld, you can use less amperage. 6mm aluminum takes about 200 amps minimum to get a puddle regardless of the AC balance. 8mm nearer to 250 amps. And you’ll need at least a 26 torch or water cooled to work with those. A 17 style will get damaged rather promptly with your amps set to max. And if you take too long to get a puddle, the interior just gets gelled up and you’ve got a mess on your hands.

Any metal warps with welding. Thicker warps less, but it will still distort. Welcome to metallurgy.

I'm using a 26 torch and it gets pretty hot. I doubt an ac DC welder would come with a 17. Actually I can get decent puddle once I get the aluminum nice and hot, then I have to back the amp down to about 100 or it will just run away on me. I've had better success lowering the frequency to 40 (lowest my machine will go) on these thicker materials.

What arc length should I aim for? I noticed I needed more for aluminum, but for stainless I can only get better looking weld at very tight, almost touching arc length.

There's a Facebook group called you don't know s about welding. Guys there all tell me to get foot pedals and a furrick number 16 gas lens with diffuser and set the gas to like 35 cfh or higher (which would use up my little bottle instantly). They must really hate pulse welding and says they reject any spot welds or pulsed welds.

Virtually every DC welding machine comes with a 17 type torch as a “standard” unless you specifically order a water cooled version (then a 20). A 17 will weld a great deal of materials and range of amperage, but it’s not well suited for >180 amps for prolonged welding. I have welded numerous 6mm aluminum fuel tanks with a 17, but used a significant preheat to get it done.

AC balance is expressed in two ways: time on negative or time on positive. You need to understand which your machine is doing. Your reference to “40” could well equate to 60% Negative with 40% in the Positive cycle for cleaning action. My Dynasty is the reverse. The more time you spend on positive, the harder the tungsten gets treated. More positive time can reduce the need for amperage, so it’s all a trade off.

Mine came with 26 torch, though I suppose I could order a separate 17 if I need a smaller torch. It's not DC only but the range of frequencies it allows is quite limited (40 to 100 hz).

The AC balance on it is called "cleaning action" so it is positive, and so 30 on the machine means 30% positive. I set it to 70 by accident once thinking it was the other way around and the tungsten balled up immediately.

There's no possible way to hook it up backwards anyways, because the torch wire and gas line is integrated, and power is applied through the gas outlet. There's a separate DIN connection on the negative side for stick welding though.

Nice thing about aluminum is I can use a really small cup on the collet, use very little gas, and it still works. Manufacturer says use lower frequency for thicker materials, and higher for thinner.

taiwanluthiers wrote: ↑Thu Jan 04, 2024 7:55 pm . I've found I needed to really jam the filler rod into it when welding aluminum, otherwise it wants to melt before it hits the puddle (and all hell breaks loose if this happens, the ball of molten filler rod ends up screwing with the arc), and that the arc length needed to be fairly long or else it will suck molten aluminum into the tungsten, contaminating it.

the balling is often due to arc length, torch angle and filler rod angle. the arc is heating up the filler before it gets in there. also don't forget your dealing with much higher amps plus you want to keep the filler out a bit more so it doesn't get pre heated, the opposite to stainless where you need to keep it shielded.

i doubt its sucking molten aluminum. it either went swimming, or you fed filler and the puddle rose up to the tungsten, or you sucked in aluminum dust. make sure you clean your work surface so there is no bb's or swarf or grinding dust. i have seen many times a bit of swarf go flying across the sheet and hit the tungsten.