for this video we're going to go into some detail on cutting and etching both
carbon steel and aluminum welds let's do it in a previous video and I'll link it
up right about here I experimented using this very same technique for all
positions flat horizontal vertical uphill and overhead I didn't get a
chance to do a cutting edge test for that video but the puddle the arc looked
something like this I was trying to keep the arc on the leading edge of that
puddle it looked like it was penetrating okay but the only way to know for sure
is to test it this is just one of several methods that you can use for
vertical uphill welding I found it works pretty well also a series of triangles
works but what both of them do is they keep the arc in the front or leading
edge of the puddle so I didn't get a chance to do a cut and etch for that
particular video and I decided to put a whole bunch more passes on each one of
these t joints here so I could also show the cutting edge on how it will reveal
lack of fusion or cold lap in between passes so when we do the cutting edge on
this will not only see the penetration in the root of the joint or lack of
penetration but will also see all the different passes and the layers and how
they stack in there there are several different ways you can use to cut it's
just best to use a method like a band saw or a chop saw or something that
gives you a fairly smooth surface so that you don't have to do a whole lot of
grinding this dry cut saw leaves a fairly smooth surface so I'm going right
to the belt sander with a 50 grit belt that will give me a nice smooth finish
nice flat finish not quite smooth enough to get detail in the etch so I'm gonna
go ahead and go to a 120 grit and I'm gonna crisscross the scratches so that
I'll know when I got the 50 grit scratches out of there you can already
kind of notice you can see a little bit of detail already on where the weld
begins and where it ends but I'm gonna go ahead and take it down a little bit
smoother starting off with a brown scotch brite then stepping it down to a
red scotch brite pad and then a gray one and that should be about enough for
etching I'm going to be using this passivation solution made by a company
called chem clean. another easier to get solution
is just naval jelly rust remover and I'll show that in just a few minutes but
you can see how this really really reveals each weld nugget and how much
penetration I got and also even each layer of weld and whether I got adequate
fusion in between layers or whether I got cold lap then I take a picture and I
pull it into some type of editing program and snap lines on it so I can
tell where the root of the joint is you don't need any super special editing
software to do this you could pull this image into something like Microsoft
Paint even it would it would draw lines like this I did an overhead multipass
t-joint not too long ago and just want to show you this is a fairly rough
finish but it's still etched just fine best practice though is to get it just
as smooth or as close to a mirror finish as you can with the equipment that you
have you'll see more detail if you get a fine finish especially if you're going
to be using this Loctite naval jelly rust remover it works just fine it takes
a little bit more swabbing to bring out the detail but it does the job it's easy
to get at any big-box store and it also helps to once you're finished with the
etch to kind of play a light source at different angles around it you'll see
more detail let's take a look at aluminum now aluminum is really easy to
cut and really easy to etch some time ago I was testing out different
waveforms on aluminum what you see here is called advanced pulse also called
mixed TIG where it's alternating between AC and DC en I have read about all kinds
of claims on how much penetration it got I wanted to see for myself so I compared
it against all the other wave forms like triangle wave soft square advanced
square whatnot I cut this just using a hand grinder and a cutting disc and then
I polished it just like normal taking it all the way down to a blue or gray
scotch-brite disc i labeled them so I wouldn't mix them up and you can see
that the the major wave forms like triangle soft square advanced square
we're all very very similar but when I got to that advanced TIG where it was
alternating between AC and DC en what a difference
so I got to test it and see for myself the difference in penetration instead of
taking somebody's word for it so then I also welded this quarter-inch lap joint
by hand and that way I could get an idea of what it would do with filler metal
added and again tested it got some results in a matter of minutes I thought
I would weld another quarter inch lap joint using a 200 amp inverter machine
full pedal 200 amps quarter inch I'm using a big 1/8 filler metal and to me
it looks like it's not quite getting in there like there's definitely a little
bit of a void on there in the root of that joint I'm kind of packing filler
metal in there I know it's not as hot as I would like it but for the purposes of
just correlating the puddle and the arc shot to the actual cross section I
thought it would be interesting so I cut it with that same dry cut saw I went
right to 120 grit right to the red wheel followed by the blue wheel or gray wheel
and then I'm gonna using straight-up Easy Off oven cleaner for the etchant
here and it works just fine for aluminum doesn't take very long either I've got a
fairly good polish on this now I got a result and not only do I have a little
bit of straight-line effect toward the root of the joint but I got a little
cold lap out by the toe here again I snapped some lines once I pulled the
image in to see exactly where the root of the joint is I got some penetration
here and there but not what I would want to see now this I know is not going to
be good so I'm doing this on purpose I dropped the amps by 50 slamming some
big 1/8 rod in there and you can see I'm tunneling I'm getting lack of fusion at
the root of the joint but we're gonna see exactly how much cuz you just saw
that now you're going to get to see the cross-section here immediately no
surprise there I knew there was going to be some lack
of fusion and did not know I would have as much porosity as we see there but
that is why we test get a lot of information and one test is worth a
hundred opinions
you