hey Jody here we're welding a root pass today. stainless steel flange
carbon steel pipe we're gonna be talking about some purge tips for tack welds as
well as the entire weld out some techniques were putting the root in
there as well as some nice instructive clear arc shots first thing is make sure
everything's clean no mill scale on the carbon steel side eighth inch gap
feathered edges no land. and now to get a purge on this before I put tack welds on
it I'm going to need either two cylinders with a flow meter on each or a
dual flow meter I've been trying out this spark brand
dual flow meter now for several months and I just added it to the store good
for purging good for running two welders this one comes with enough fittings
where you can use either hose clamps with your own hose or a regular inert
gas hose I'm using the regular inert gas fittings today once I got it hooked up I
got one one side hooked up to my machine the other side hooked up to a purge line
I'm using this little purge box here to get tacks on so I don't have to tape up
and wait on a purge little argon boxes like this are really common in aerospace
this is one that I made and used when I was doing aerospace work look what a
good job it does on shielding the tack and it's immediate you don't have to
wait so as you turn the argon on you got a purge after all the tacks are
feathered with a grinder except for one I let it purge for five minutes at 25
cfh here's a little close-up of my TIG gloves that I added to the store some
months ago the technique I'm going to be showing goes forward and back not
side-to-side so I'm wearing a TIG finger for that that's the technique I'm
using today eighth inch gap 95 amps for the root this is the technique
basically forward and back with very little side-to-side motion walking the
cup is a great way but you can't always walk the cup I'm just showing this
particular technique that has always worked for me for stainless roots as
well as carbon lay wire 1/8 rod 1/8 gap only forward and back motion and no
side-to-side it's difficult to do that walk in the cup here I'm coming up tying
in to attack so I'm slowing down kind of soaking the heat in there make sure
everything melts and blends together nice before
I snap out of it I didn't mention it earlier but I'm basically just keeping
everything taped up here and only leaving open the areas that I'm gonna
weld to an extent here I'm going to show the technique when I don't feather
attack if you're coming up off the bottom or off the side this is a
technique that works for me basically what I'm gonna do is just really quickly
fuse the wire to the tip of the tack back up a couple of ripples pause for
about a second and then forward and back and blend everything in together and
I'll show you that tie in here in just a minute I didn't touch that with a
grinder and it's still going to work out just fine now that's only coming off of
attack I do like to have a tack feathered that I'm welding in two so
that it makes sure and gets full penetration and blends nicely in to
attack that I'm welding in two so again forward and back forward and back
keeping a little pressure on the wire 95 amps pressure on the wire so that
doesn't keyhole so that it keeps the puddle kind of satisfied and now I'm
welding into that feathered area of the previous tack slowing down and then
trailing out snapping out catching my tape on fire putting it out with argon
there is the tack of where I started without a feathered tack right there
there's the tie in I don't usually feather my tacks a whole
lot on a stainless joint like this so I'm gonna show you now the same exact
technique on a tack coming off a tack where I feathered it a little bit gonna
do the same thing I'm gonna go ahead and get that wire fused in there so then
keyhole when I get there back up a little bit and then move
forward and back keeping a nice tight arc forward and back forward and back
very little side to side I come up on the very top and things are a little hot
I'll definitely move a little bit side to side but for the most part it's just
forward and back and then it's always a good practice to speed up kind of Comet
trail out up on the up on the wall of the bevel instead of on the route pass
I'm using a lift arc function on the TIG welder today I've got a foot pedal and
everything but I'm not using it today I'm just using the lift arc now that I'm
ready to close this thing up this is the last little one-inch section I'm
reducing my flow to about 10 cfh and I got to make sure that I
have a vent at the uppermost point and I'll explain that in just a second let
me show you this little demonstration I did a while back using a water jug it
really drives the point home why you need a vent and every uppermost area in
whatever you're trying to purge it really helps to think of argon as water
it's heavier than air so it goes to the bottom and displaces the air if you've
got an area like this with nowhere for it to vent it's going to be trapping air
and swirling around and you're not going to get a pure argon purged so what you
need is a vent just cutting a little hole in here a little vent hole allows
things to fill up a lot would allow that argon to completely displace the air and
allow you to get a good purge let's close this thing up there's only about
an inch here we've already seen plenty of Ark shots I increase the amperage to
105 here that's up 10 from what I welded the rest of it that's because this had
started to close up so it's more like a 3/32 gap there I need a little bit more
heat to make sure I break the walls down then when I tie in and snap out take a
little quick peek at it stay tuned for the hot pass and cover pass coming up in
in a video pretty soon here's some little teaser shots for that let me
quickly go over the products use in this video this is the spark dual flow meter
and these are my new tig gloves not really that new anymore
I searched for a long time to find some durable yet really comfortable tig
gloves this is my TIG finger product that just excels on things like this on
stainless steel pipe let's you prop right next to the weld and finish that
pass without roasting your fingers