[Mac's Crew]

Howdy Folks,

First post here, and while my machine has pulse I have never used it. To be honest I am not opposed to using the feature, but I don't truly understand why I would need it. OK I know that it is not NEEDED, but why would a person want it? Lord knows that I am not the best welder around; but I am decent. I have a machine that has more options than I have used (mainly mild steel, some aluminum).

I got the machine for a steal... Thermal Arc 200. I have downloaded the manual, but not sure when I would need some of the features included with the machine.

Thanks
Mac

[EngineerIsWelding]

I'm a pretty new welder, but since I have done some experimenting with pulsing on carbon and stainless steel and aluminum, and because more experienced welders haven't chimed in, I'll put in my two cents. I've worked mostly with thin material, 1/8" (11 ga) to a little less than 1/16" (18 ga).

I've found that pulsing is beneficial in some situations, but it doesn't make a night-and-day difference. If you've learned to use a pedal effectively—controlling amps generally and maybe pulsing with the pedal when needed—you can certainly get by without pulsing. I have only found pulsing to be useful at low and high pulse rates, and for different reasons.

For low rates, I've had success with pulsing at my dab rate, about 0.5 to 2.5/second. Add filler when the amps are high, and either move continuously or move when not dabbing. With the right combination of main amps and background amps and high/low amps ratio, you can reduce overall heat input. Should be helpful for thin materials, especially stainless and aluminum.

For higher rates, I think Jody is right on with his "rule of 33s." 33 pulses/second, 33% on time, 33% background. Higher pulse rate is also ok, and it may be best to vary the other parameters for your specific situation. As he explains in several videos, these settings can keep the puddle from wandering or nibbling away at the edge when you're working near edges. A plumper bead if you want. With it, you can add material to edges more easily to build them up.

I'm sure there are other reasons for pulsing, and maybe folks more expert than me will chime in. I've only done a little searching on the topic—that should reveal more detail for you.

[Oscar]

Generally speaking, pulsed welding current can be beneficial in different ways depending on the settings, but overall it is another form of heat management/control that the weldor can transfer over (from his own knowledge) onto the machine to have it do it for him/her.

Some of the ways pulsed current can be set-up is to

A) obtain good fusion (a characteristic of high amperage welding) while
B) not over-heating the part/parent structure due to the chilling effect of the "base" (lower) current portion of the pulse waveform, and sometimes assisting in
C) superior weld pool agitation/filler metal dilution into the base due to liquid currents induced in the weld pool due to arc pressure and electromagnetic fields,
D) a more "directed" arc is produced when pulse/duty cycle parameters are set in certain ways

Study on Fast-convert Ultrasonic Frequency Pulse TIG Welding Arc Characteristic

Arc & Weld Pool Behavior for Pulsed Current GTAW


TIG - Direct-Current Welding with High-Frequency Pulses, an Interesting Process Variant

[tweake]

i only have two fixed pulse settings. (entry level machine).
i find it very helpful on thin stainless. this means i can run higher current settings which i can control a lot better than the lower amps.

[LtBadd]

Mac, welcome to the forum
Are you welding projects for yourself, and/or are you doing work for customers?

Pulse settings cover a very broad range, from slow to high speed pulse and everything in between, but it's not just
the # of pulses, it's also the % on time and background % you can play with

Jody's 33 pulse rule is just a starting point he suggests, experiment for yourself to learn

I've found I use pulse on stainless a lot, with aluminum you need a lot of amps and pulse works against you here.

It's easy to get lost with all the possible variations of settings, mostly I like it for reduced heat input and it also helps to maintain a stable arc, especially if your welding in a tight area where the arc could wander off into an area you don't want it to.

Below is a pic of a part I used to do, the weld had to be made after the 3/16" dia tubes were tacked in place, and the weld needed to be helium leak tight, it typically wasn't a good looking weld (under the tubes) but it past the leak test. I used a high speed pulse to help keep the arc focused.

Img_1359.jpg (42.13 KiB) Viewed 2591 times

[Mac's Crew]

Just doing work for myself and the beautiful lady I get to call my wife... getting the kids interested and basically being a pain in the wallet.

Sent from my SM-G960U using Tapatalk

[Mac's Crew]

Also thank you for the replys and Oscar now I have more to study.

Sent from my SM-G960U using Tapatalk

[EngineerIsWelding]

Oscar's links will take you into some of the theory and explanations of pulsing effects. Jody discusses pulsing in quite a few videos, and here's one that covers a number of examples. He shows the effect on travel speed, penetration, edge build-up, etc.
https://www.youtube.com/watch?v=V5OhIc7R6r8

[EngineerIsWelding]

Oscar's links will take you into some of the theory and explanations of pulsing effects. Jody discusses pulsing in quite a few videos, and here's one that covers a number of examples. He shows the effect on travel speed, penetration, edge build-up, etc.
https://www.youtube.com/watch?v=V5OhIc7R6r8

[BillE.Dee]

Golly Gee, Richard. I'd bet that you had to use a creeper on top of a step ladder to get under those tubes. There can't be too much room for the torch underneath there.
As far as pulsing goes, a person has to get used to "their" machine and general needs for heat control. The pulsing can also help a person get used to adding filler and training muscle memory. There's always a way to skin a cat. Practice and more of it ... every day is a learning experience.