Welding Tips and Tricks

Can you visually tell you are welding with enough amps?

As in, when you push down the pedal to initiate the arc and increase amps, at the point the weld pool forms; have you reached the amount of amperage to start the weld? And, once the pool forms and have reinforced the bead with filler metal; are you able to lift off the pedal regardless of the amount of amperage backed off as long as the weld pool remains fluid?

(i.e., if you were to keep backing off the pedal, at a certain point the weld pool eventually solidifies. If you were to push the pedal back down from this same point the weld pool will at a certain point form again.)

To add, is the 1 amp per 0.001" thousandths of an inch rule of thumb just to get the weld started, or do you need to keep your amperage fairly close to this amount throughout the weld to get the necessary weld penetration?

I am no pro by any means, in fact I'm pretty new at this, but just speaking for myself I started out using the 'one amp per thou' rule to get in the ball park, and adjust it from there using pedal and eye.

Required amps change all the time as you weld. The one amp per thou thing will get you started, in my experience as the 'main welding amps', but as you add filler (depending on filler thickness) you might find you need more amps; as the work piece heats up you might need less; as you approach the end of the piece you might also need less. I can now certainly get a good idea of whether I need more or less just by watching how the puddle behaves, and as I gained experience, to be sure I was on the money I cut up a lot of welds to check for penetration. Most of the time what my eye tells me while welding seems to be pretty much right.

Also, unless you are fusion/autogenously welding, I always consider that I have reached initial welding amperage once I have formed a good puddle and successfully added my first dab of filler.

Hope this helps. More experienced souls than I will no doubt chime in soon enough.


Kym

I was about to post almost the same thing as MM. The variables to your question are as endless as can be. Mass of material plays as big a roll as material itself. Remember when you apply heat to anything it immediately begins trying to get rid of that heat. Once your up to a temperature that allows for a good weld puddle you can almost always back off some of the amps without penetration or quality suffering. How much to back off is more art and experience than science. Even welding two identical parts cut from the same sheet will weld differently due to subtle changes that would only be detectable from a test lab perspective.

dynasty200sd wrote:Can you visually tell you are welding with enough amps?

As in, when you push down the pedal to initiate the arc and increase amps, at the point the weld pool forms; have you reached the amount of amperage to start the weld? And, once the pool forms and have reinforced the bead with filler metal; are you able to lift off the pedal regardless of the amount of amperage backed off as long as the weld pool remains fluid?

(i.e., if you were to keep backing off the pedal, at a certain point the weld pool eventually solidifies. If you were to push the pedal back down from this same point the weld pool will at a certain point form again.)

To add, is the 1 amp per 0.001" thousandths of an inch rule of thumb just to get the weld started, or do you need to keep your amperage fairly close to this amount throughout the weld to get the necessary weld penetration?

What you just described in your question is the entire art of arc welding, whether it be SMAW, GMAW, or GTAW. It all boils down to "reading the puddle". Where this puddle forms/exists is what makes welding so intricate as well as the existence of literally thousands of different alloys of weldable metals. As was mentioned before, there are endless combinations of weld joints/configurations/orientations that all change the behavior of the molten weld puddle.

My answer is: sometimes. When I am welding a familiar/previously welded joint/configuration/orientation, I can usually tell if I have enough amperage for my required bead-size and/or fusion depth. If it is unchartered territory for me, then it becomes harder, because it is mostly all based on experience; which is why most professional welders receive schooling/training to learn before going out on the job. Pretty much anything in life follows this schema.

You will definitely get a feel for it the more you weld. What I have noticed it that if you are welding most types of steels, you can physically watch the puddle dance as your weld penatrates all the way through. Usually it will start to swirl just before it blows out. I think it is good to run test pieces and figure out how much heat/amperage is required to blow a hole in it haha. Keep in mind that fit up and joint style will often play more of a role in amperage then overal material thickness.

when in doubt weld a test piece and bend and beat it.
even cut and etch it till you develop you own perimeters.
craig

Yes, that's the whole key to welding. Reading the puddle and lots of seat time. It's all about practice.

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soutthpaw wrote:Yes, that's the whole key to welding. Reading the puddle and lots of seat time. It's all about practice.

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Yup and the extra fun part is that every heat batch is different to weld and that is why orbital welding is so damn hard sometimes.