Hi, I'm Josh from Brown
Dog Welding and today we're going to do a little
bit of silicon bronze work. We're going to talk about why you'd use it, when you use it, when you wouldn't use it. The things to look out for when brazing, when TIG brazing with it. And I'll show you some kind of, the things that can
happen, that can go wrong, and how to correct them. And that's what we're
going to work on right now. Warning, read and follow all
labels and the owner's manual. So right now we're going to
do some silicon bronze beads. We have the welder set up just like we would on stainless steel or steel on DC. We're going to show you how to
kind of start the bead going, it's not a traditional puddle. You're just, you're not
melting the base metal, you're just getting it hot
enough to take the material. So we're going to do that right now. So you can see kind of some
heat forming on the surface, and you just dip the rod
into the leading edge, making sure to keep it
within the protective zone of the gas coming out of the cup. See it's got that nice clean center. Then coming off of it, push
a little filler in there come off to the side, otherwise, it'll want to crater. So that's just a bead, a brazed bead run with
silicon bronze on DC. All right, now we're going to show some, kind of some don'ts with silicon bronze. The first time I'm going to go through it I'm going to do something kinda cold, and then I'm going to come back through it and do something way too hot. There's a window for getting that, just that right flow with silicon bronze, and it's a little bit tighter than with regular steel, with mild steel. So, we're going to watch what happens when you don't quite hit that window. So here, too cold. So if you had the wrong angle, it'll just ball up. It won't want to take into the metal, until you, kind of add a little bit to it. But then, start doing it too cold again, and it lumps up at the end of the rod, it gets kind of nasty until you even it out again. See how it balls up there? That happens when you don't have a good angle on the workpiece either. Too hot, you've made a puddle. Like you would with a regular weld bead. It get's way too hot, and it washes out. You can see it wash out. The puddle is still fairly decent, but you don't want a puddle with this. You'd rather it be kind
of on the top like this. You start doing this, and it pulls the base
metal away from itself. All right, so here you saw what happened when the base metal, even when it's warm, how not having the
right amount of amperage coming out of your torch
can affect the profile. You don't have any
penetration here whatsoever. Not that you necessarily want
penetration in the base metal, but it should wet out. It should wet out, and you can see on edges where it's right, how it just kind of transitions
nicely into the base metal. Whereas here you can see
it's obviously not fused. And it's really easy to go from warm, to having it right, to going cold, to going warm again. It's difficult to get it
consistent, so you really want to practice on having it
right in that right window. Now if you get it way too
hot, this is what happens. You get it kind of smutty, it's dirty, and once I
clean this off you'll see that there's actually
cracks throughout the base, the base of the weld. So it's actually, and it
cracks all the way through, so it pulls the whole base metal apart. It's a hot cracking rod,
as they would call it. So you don't want it too cold because you won't get any fusion, and you don't want it too hot because you'll end up
getting cracks like this. So you can see there's a big divot there, there's a crack there. There's little fractures
all through the weld. And on the back side, it's hard to tell, but there are actually fractures that you can see right in this area and a couple others are
hidden along the grain. All right, so now we
have the Multimatic 220, and we have it on AC, so we're going to do some TIG brazing with AC. Right now I have the balance set up at 80. So, 80% of the time
you're welding like, 80% of the time
it acts like it's DC, so it's not so far from DC that it's going be
foreign to how it flows. And I also have the
frequency turned up to 150, and as we weld we're going to adjust that to kind of show what it does, the stability it gives, where you might find the sweet spot, and what happens if you
get it way out of whack. So you can see it is
cleaning the base metal, and that the high frequency, it really gives it a nice clean bead. Now it's going down, and it's
wetting out a little more. I'm dropping the amps to
kind of keep up with it. Now it's going way down, and you're getting that real flat puddle. It's starting to sputter a little bit. So you can see right here the difference between welding with
DC and welding with AC. Even with the AC with
the balance turned way up it's got this nice clean bead. Neither of these have been brushed at all. So just obviously, right off the bat you can see the difference.
The AC cleans really well. The DC, to me, flows a little better. You know you're able to keep
your edges really nicely, but you'll get this layer
of junk up at the top, and with the AC, you're
already cleaning that away. You can see where the edges
are broken up where the kinda the white little fuzzy areas are. It's just like the outside
of an aluminum weld, where it is breaking the oxides and pushing them out of the way. So you'll see that this has a much wider heat affected
zone, this is a narrower HAZ. And you're seeing obviously where the cleaning action took place and pushed everything kind of out of the way so you've got this nice clean surface. Now with the DC you can brush it and it's going to look really nice. But just right off the
bat if you're trying to lay down something
that looks really good without a lot of post-prep, AC is the way to go for sure. To check out more of my work, you can go to BrownDogWelding.com, and to learn more tips
and tricks about welding and even some electric
brazing, go to MillerWelds.com
