🔥 Walking the Cup with MIG: Downhill Root, Uphill Fill and Cap | MIG Monday


welcome to well . com I’m Bob Moffatt
welding instructor with Cowley College welcome to weld. com I’m Bob Moffatt
welding instructor with Cowley College I actually want to try to walk the cup
downhill on a root pass and finish the subsequent passes uphill this is a kind of a procedure that would
follow over in the pipe as well so i have plates 30 degree bevel I want to fit these with
about a 5 30 seconds to three sixteenths gap and I want to run a downhill root
today I know there’s some argument about
whether you run uphill downhill which one’s stronger I want to show you that this is a it’s
it’s a good process we’ve used this a lot in the piping industry especially on
rolling pipe where we’re using a flux core process to filling cap it’s in a it’s approved procedure we’ve
tested this and it’s it’s strong so I want to get some gear on I want to
attack these plates up and run this downhill root for you I want to show you how easy this is I
want to start this I’m gonna I’m gonna hold this i’m pointing this up I’m gonna
come off of my tack up here at the top of the plate my wire is pointing up hill
about 30 degrees after i get going for about a half inch or so I’m actually
going to take my right hand away and run this one-handed and I’m gonna walk the
cup downhill I’m just sliding this along and I want
my wire to stay on the leading edge of the weld pool always if I outrun this and I shoot the
wire through a dead air space and I don’t have a park anymore ok so let’s start out up
here at the top so when I started this world from
backing up i did make a slight change in voltage and amperage simply because i
was going to have a slightly longer stick out I was real confident with the gap and as
you can see you just gonna walk in this down and gently going back and forth on
the leading edge just to make it to make the web full progress you know this i’m not
saying anyone’s thoughts too long again i’m running this one-handed yeah full penetration with just the right
amount of reinforcement I ran the root on this downhill I’ve
already buff the glass and slag out of the inside with a flat wire wheel I want to put a Phil pass and a cap except now i’m going uphill never i
never want to well downhill in a groove there’s too
much chance of lack of fusion the minute ago when we did the route we had our
wire pointing up hill about 30 degrees and i stayed on the leading edge to get
my fusion and control the backside now i want to point my wire straight in
or slightly downhill believe it or not that’s the biggest problem that I see
with a lot of students and amateurs is the point there wire uphill to go uphill okay you need to think about getting
that wire driving it into clean material down inside the groove so that you’re
getting the proper fusion also if you point your wire uphill if you’ve ever seen anybody do this you
will see a lot of spatter buckshot bebes coming off the front edge okay that’s that’s not fun your machine
actually runs nice and crisp and clean if you’re pointing it straight in ok there’s a there’s another little
subtle technique that i really want to discuss here and it’s i’m filling this
groove up you’re going to ask me what well how do you weave do you just go straight across well the
answer is yes and no if I have a lot to fill up then I want to build a little
shelf down here my filler metal I want to bring the wire up into the
center go across to the edge and then come straight across it’s like a lazy triangle ok and the
total movement of my wire up is probably an eight to three sixteenths of an inch tops now pause on the sides i want to
pause on the sides of this bevel face and I want to watch that tie in the center of it will take care of
itself my whole philosophy and doing groove
welds is I wanted to be flat I want to be able to clean it whatever
past that I put in after that I want it to be flat so that I’m not welding over
the top of a big hump ok so I’m going to start down here at
the bottom yeah hey guys today’s episode is brought to
you by the pond dick welding supply they’re giving away in Esau rebel King
just like this used in today’s episode for a chance to win this sign up to their email list get back to
welding since i’m going to do this well in three
passes and I’m pulling this wire up in the center and refilling the center and
leaving to the outside about not probably 3 30 seconds seven inch – my
bevel dead again i want to leave my beveled edges alone because they’re my
guide when I go to my cap straight edges i want to run a stray cat turn the feet the studying Electrical
stick out simple repeatable motion yeah via a buff this out and i’m getting
ready to put the last pass in here I wanted to talk briefly about the
objectives of of what we’re getting ready to do here no undercut we don’t want undercut on
the edge of the bevel on the edge of the group face and I don’t want my
reinforcements on my beat height to exceed an eighth of an inch that’s pretty simple I’ve left myself
enough room to run this last pass in here naturally and again it’s it’s the
exact same motion and the exact same wire angle I want to . this in and go uphill with
it yeah yeah the motion i’m using now is simply a i
guess you could call it a lazy oval not really going up that much I don’t need to I am staying on the leading
edge of my weld pooll and I’m watching my edges to make sure that they’re using
into the plate Little pause there One thousand and one… One thousand and one we finished this welld here and we’ve left
the subsequent passess alone again we ran a root pass down hill in this groove we ran a fill pass up hill and we
stopped up here so that we could see it and then we ran the cap or last pass there’s a couple things to note here I
don’t have any undercut on the sides and a lot of my glass and and deposits were
in the center of the bead here and you’ll also notice that the ripple
pattern is more it’s it’s pretty smooth and they’re
fairly scrunched together I like that I as it is if somebody that
was an inspector that would look at a well I don’t like the great big cat paw
look on the on the MIG welds they’re kind of cool and you get to the
tick but with a MIG I like this because i know this glass is floating to the top
we’re not trapping it into the bead so again no undercut and we buffed this
off it should look pretty clean thanks for watching that’s it for this episode new episodes
are every Monday make sure to subscribe

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