Tip:
Highlight text to annotate it
X
Hey guys. I wanted to take just a minute. A few minutes here and talk about mig welding
technique when you are doing difficult welds. I think the most difficult weld to do is a
butt weld on a piece of sheet metal. And I've made a few videos welding patches into cars
and things like that and I've made a couple other videos welding on the bench. And what's
interesting is of all the videos I have, one of the ones that gets my top views is one
of the first videos I made which was on mig welding technique. And, I sorta covered some
things in that video but I thought it would be worth another look at just straight up
- How you deal with a difficult situation of butt welding sheet metal.
So, I may have to do this in a couple different clicks just depends on how well focused I can be. What
I tried to do is take a difficult situation here and these are welds that I did previously,
this was another piece to another thing. But I took just two pieces of scrap and I made
kind of a funny line here just to make it difficult to weld. And I didn't cut the line
particularly straight so the gap is nice, nice, nice, and then it widens out and widens
out even more when we put all this together. There you can see it a little bit better.
So this is not going to be easy to weld. I'm using a 110 volt Hobart Handler and CO2 right
there. C25. And I really prefer the 110 units. The 220 units will do just fine but the 110s
as far as the millers are concerned anyway just seem like they have a softer, a softer
weld I don't know how to explain it, its just feel. I've done a bunch of welding in my life.
I'm not really dressed to weld, but I wanted to make this video so please excuse the sweatshirt
I would normally have a welding shirt on but I wanted to show you guys how this is done.
I did not, I did not make this. I've seen a lot of videos out there that show this perfectly
sheared edge, you know, and welding two perfectly sheared edges together really is very, very
easy. But when you get these kind of hand cut things here it becomes more difficult.
And I'm not. I don't have a heat sink behind here or anything else, but what I do have
is a body dolly. I use this all the time with a copper sheet just kind of pounded over it.
You can hold this behind your welds and weld to it if you get to a particularly difficult
spot. We're not going to use that tonight. Basically that will just make things easier
for you later in life. I am going to wear my auto darkening helmet here and away we
go. So I'm going to start where this clamp is. And, you know, I suggest whatever you're
doing, always clamp your work it just makes things better. We're going to put a weld right
by the clamp.
(welding)
And if you were looking at this, you would see the back part of the weld eroded
just a little bit and so the next thing I'm going to do is probably closer to what you guys
would do at home where you can't get a clamp in the middle of a panel. I'm going to lift
this up so it's not touching anything. I hope I don't knock my camera over here. Hang on guys.
(welding)
So there's a nice little weld right there. You constantly want to take a look
at whether or not these surfaces are parallel and if they're not, you take a hammer and
make them so because if you weld them and they are uneven, they'll just continue to
be uneven. The other thing to keep in mind, and this is a huge deal, is the distance of
your mig gun to the work. The further away you get, the less heat you have. So if I have
a really difficult spot. Let's come out here where there is a big gap and I'll show you
what I mean. Can you guys see that, is that in there? Let's see if I can lift this up
just a little bit, hang on guys. Put my clamp on my work here. I'll try and lift this thing
up so you guys can see. You know, we're a substantially large hole right here. In order
to fill that hole, if you hold your gun back, and I'm going to weld here.
(welding)
That's how you make it happen right there.
so, yeah, you guys can see, we bridged that gap. So you
hold your gun back a little further from your work piece. I hope you guys can see that,
let's try it this way.
(welding)
So there we go, that's how I would do that.
It's not the prettiest thing when you have these big gaps, but if
you have them, that's how you go about getting to them. The other thing is, once you establish
a bridge across here, that's the spot that you aim at so that you are hitting the thickest
part of the metal, you know, wherever you weld is going to be the thickest part of the
metal. Now we can pick up on this where the metal is nice and tight and you'll notice
how easy it is to weld that. Watch.
(welding)
And you'll notice. I'm just stacking one on top of the
next on top of the next. Those are fairly flat there, they aren't stacking way up. I
hope you guys can sort of perceive that. But that's how you butt weld on sheet metal. It's,
it's sort of a, you know, a rhythm, you can hear that, zap, wait, zap, wait. So the different
things you can look at is how straight your gun is to the work, that makes it hotter.
The more angle you get on there, the cooler that weld. And the further you get away, the
cooler it is. So it's sorta like you spread out the intensity the more angle you get.
I'll bet if we go straight in, I can melt right through that, let's see.
(welding)
Can you guys
see that hole through there? That's what happens when you weld straight on. So, a lot of people
get really discouraged because you look at all the pictures of mig welding and it always
shows this gun pointing right into the thing. Just go like this and I'll bet we can fill it up.
(welding)
Hey, check that out, we got a little bonus there. So yeah, so there's how you fix
your problems when you get stuck in a hole like that, just tilt your gun down and point
at the thick spots. So hopefully that's been helpful for everybody, that's how you butt
weld. This is, I think, 20 gauge sheet metal so it's pretty thin. This is pretty indicative
of what you'll find on a lot of cars 18 to 20 gauge sheet metal, so have fun with that guys.
Don't let your meat loaf!