we're doing 5g pipe today MIG all the way short-circuit MIG downhill root
uphill fill-in cap before we get into that since I think it's a good idea to
do plate before you do pipe and if you do plate the same thickness and the same
bevel angle as you do pipe you pretty much nail your settings down for that
this is a 3G plate roughly the same thickness with the same bevel angles as
the pipe I'm gonna weld the gap is set at 532 so the settings will be slightly
different for the route technique is roughly the same stay on the leading
edge of that puddle but not so far on the leading edge where you shoot wire
through the backside that's the ticket for the fill pass I increase the wire
feed speed a little bit and I want to wind up here about a sixteenth lower
than flush need to be a sixteenth lower or it's very easy to put the cover pass
on there with too much reinforcement and a lot of codes limit you to an eighth of
an inch maximum reinforcement on a cover pass letting it cool between the fill
pass and the cover pass to where it's warm to the touch I've reduced the
voltage just by a little bit and the wire feed just by a little bit as well
and I'm trying to move fairly quickly across the middle while holding the toes
to prevent undercut now let's see how those techniques apply to a six-inch
schedule 80 pipe same bevel angle except with a 1/8 gap I'll be using a eSAB
rebel 2:05 here this is the ACDC one that TIG welds aluminum it's got an
inductance setting for the MIG so I'm setting it a little bit higher than what
it recommends I'm gonna try to well from 12 o'clock all the way down to 6 I'll
just be doing one side of this pipe today I've got a tack at 12 an attack at
6 and you could see earlier that I had a little area there where I was kind of
dialing in some settings but the same technique on the root pass keep that
stick out fairly short keep on the front edge of the puddle make sure to have a
really good solid ground that makes a big difference when you're welding an
open root pass but don't stay so far on the leading
edge of the puddle where you shoot wire through the inside I took this test a
long time ago at a fab shop I worked at and it wasn't the higher-end test it was
just a test that I needed to get so that there was no pressure like there would
be on a higher end I wasn't like the job dependant on it but for some reason the
instructor wanted me to go all the way from 12 all the way to 6 and then he
wanted me to not even stop at 6 o'clock and turn around and we'll all the way
back up to 12 I'll tell you that's rough on the lower back if you've got any
lower back issues but I did it and I did two or three practice joints and I was
ready for a test so then when I got my tests tacked up and got the inspector to
come over and sign off on my fit up I said so we're doing this the same way as
you had me do earlier and he's like now just messing with you go ahead and stop
at 6 o'clock and rest I also thought it was kind of weird that he didn't want
any tax at 3 and at 9 o'clock but that's what the instructor called for that's
what I did I came out a little flat on the overhead
part of this I think if I would have dropped my voltage a little bit and
stayed a little bit more on the front of the puddle that would have come out
better so for the fill pass I'm gonna bump it up to 19 and a half volts and
fairly low on the wire feed speed 200 that's all going to depend on how big of
a root you put in there just like the plate I want to be about a sixteenth of
an inch below flush before I put the cover pass on this thing but I do want
the the fill pass to wet out I want to make sure that I don't have any cold lap
between this pass and the route pass and sometimes it's just best to live with a
little bit of spatter and have the pass lay down a little bit flatter I prefer
having my wire feed speed set to where I don't have much spatter at all but you
can see I've got a bit here part of that's gun angel' but part of it is only
200 inches a minute wire feed speed but it is kind of laying in there pretty
good partly due to some pretty good settings
but partly that sort of rainbow technique that I'm using and the reason
I'm doing that is because kind of traces the leading edge of the
puddle so it's sort of an upside down you or a rainbow or whatever it's just
the shape of the leading edge of the puddle and it sweeps the arc across the
leading edge and then I back up a little bit which kind of helps fill in the toes
and helps keep it flat across the surface which makes the next pass go in
a little bit better I shouldn't have to grind this at all
before the next pass at the end of the video I will do a cut and etch a
cross-section test just to make sure that we don't have any lack of fusion
between passes or any voids or anything like that I'm in pretty good shape here
as far as being a little bit below flush it's always a good idea to snip your
wire to clean out the spatter in between passes last thing you want to do is dump
a doughnut of spatter when things are going really good all right for the
cover pass it's almost like welding a bead on flat plate so you don't need as
much heat you're not filling up any kind of a groove or anything so I'm reducing
both wire feed speed and voltage 18 volts 180 inches a minute and we'll see
how that works taking a few dry runs here again get
comfortable to know what I'm up against try to keep the gun angle straight in
toward the center of the pipe it's especially important on the bottom I'm
moving pretty quickly across the middle again and pausing on the toes and it
occurs to me on the bottom of this thing I probably should have let the pipe cool
for 5 to 10 minutes before coming on the cover pass like this
you don't want the pipe to be too hot it's just hard to control the metal you
can always compensate by using really low settings but I'd rather let the pipe
cool off a little bit and I'm kind of fighting it here and it's not coming out
as pretty as it should it's a little irregular because I'm kind of having to
just really scoot across that middle so I'm gonna stop here and let it cool for
a few minutes let's get back on it it's still very warm to the touch but not
quite as hot as it was before things should go a whole lot better
not having to go quite as fast across the middle still not wasting any time
there I can just tell it's it's just a whole lot more controllable I didn't
change anything as far as the settings go I just let let it cool off a little
bit and of course I'm getting to the easier part of the pipe to once you get
up to the you know to the nine o'clock position or the three o'clock position
things are just easier than they are on the bottom anyway but generally speaking
if you let the pipe cool you can make it look just as good on the bottom as you
can on the sides and on the top again trying to point that gun toward the
center of the pipe I don't get carried away with the with the gun angle a
little bit of push not a problem you just don't want to get completely out of
scope and it's easy to get out of scope on the top of the pipe so the way to get
around that is just chicken wing that elbow and point it toward the sky get it
up good and high when you're on the top it'll keep you with a good angle at 12
o'clock now I know there's going to be some people asking wide and weld the
root uphill ...it just goes in really good downhill with a gap and with a with no
land and with a thirty degree bevel but we're gonna do a cut and etch anyway
we'll just do a little cross-section here when we take only takes a minute
these Walter zip disc wheels make short work of this so in just a few minutes
I'm gonna have a nice little section here that I can look at I can polish I
can put some acid etch on there and we'll see if there's any voids in
between the root and the fill and the cover pass this cross section was taken
around the nine o'clock position so that was kind of one of the better easier
positions but I don't see any problems there nothing jumps out at me as being a
problem I don't see any voids I don't see any straight lines this is why I
like to do the cutting edge test especially right after I weld something
while it's still fresh in my mind because one test is worth a hundred
opinions