Tips for Good Welding Penetration - Kevin Caron


Uploaded by kevincaron on 28.04.2011

Transcript:
(Text on screen): Tips for Good Welding Penetration, Kevin Caron, www.kevincaron.com
The Voice: Hey, Kevin. What are you doing?
Kevin Caron: Well, I had a really great question come in the other day. From on YouTube.
A new welder, just got his first machine, and he said, "How do I know when I'm getting penetration in my weld?"
And I thought, hey, cool. Let's look at that.
Come on down. Check it out.
So, I've got four little pieces of eighth-inch plate that I just pulled out of the scrap bucket. Cleaned them up a little.
Chamfer the edges a little so you can get a decent weld.
And what I want to do is I want to make one weld really low voltage, one weld right about the right voltage, and one weld really hot,
to kind of show you the difference between what welds look like,
and look on the back side and see what kind of penetration we're getting; what kind of discoloration we get on the metal.
Show you how much heat is actually getting through.
Put your helmet on. We'll make some sparks.
This one we're going do at 14 volts. And, yeah, I know. That's pretty cold.
(welding)
Now let's do the next one at say, like, 18 volts.
Nah, 19. OK. We'll call this one 19 volts.
(welding)
Now let's do this last one at about, oh, 22.
The Voice: Ah, come on. Give us 24, Kev.
Kevin Caron: 24?
The Voice: 24.
Kevin Caron: All right. Let's melt this. What the heck. Let's go to 24.
(welding)
Now, you hear the difference in that sound; of that weld? Compared to the first two, the third one.
God, that sounded awful. What was going on there?
Voltage is up so high that the wire feed is now too low.
So the arc is melting the wire, just trying to travel right back up in the gun, and boy it's going to make an ugly weld.
Let's take a look.
Now, remember, this is the cold weld: this 14 volts. I've turned it so you can look at it right from the edge.
See how high that is? Kind of humped up? See it?
The Voice: Yep.
Kevin Caron: And you'll look at the next one. That was, what, 18; 19 volts?
The Voice: 19.
Kevin Caron: See, it's kind of flat going across that section, like it's sunk down into the metal some?
Because that's the same wire feed. I didn't change that at all.
And now you come over and look at this one, at 24, and you see the difference in it between the other two?
The Voice: Um-hmm.
Kevin Caron: All right.
Let's look on the back.
See, here's the joint in the three different welds.
This was 14 volts. You see the discoloration, just a little bit to either side, where the metal got hot.
Now you look at 19 volts. See how much bigger the discoloration is? A lot more heat.
Now, come over here at 24 volts. Huge, huge discoloration. Lots of heat.
But because the wire feed was set wrong, we didn't get a very good weld out of it.
Let's try something else.
Hang on; let me get my glasses.
Let's find out how good they are.
(hammering)
Now, you see, normally, if you were going to cut this weld open to test it, to see how good the penetration is,
you would cut it across the weld, polish it
(there's an acid, I think, that you put on it to kind of etch the metal and then you can actually see the penetration into the metal itself.)
I don't have that here.
Here's the cold weld. You can look in there and see, boy, there's a whole bunch of the joint that's still bare.
There's no weld down in there at all.
You look at the 19-volt weld and you can actually see where some of the joint started to melt on this side.
Remember, we welded it from the other side.
And if you come over to the really hot weld, you can see that's even starting to melt through on that side.
More amps, wire feed set right, you're good.
The Voice: So how do you know when you're welding, though? That's when you really need to know if you're getting penetration.
Kevin Caron: Well, I wish you guys could see what I see when you look through the lens.
When you're (come on, pencil); come on down here.
When you're sitting there with your gun and you're trying to lay down a bead, and your weld is going on right in there
(that's where the big, bright spot is), you can look on either side in here, as you're moving forward
and you'll actually see your base metal getting pulled away; getting eaten away a little bit.
Because it's being pulled down in your molten metal.
Pay attention. Look in that area, and you'll see it's starting to actually pull that metal off and you'll see you are welding.
You are melting your base metal. You're adding some filler metal. That's welding.
Hope that answers the question. See you later.
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