[TheForge] Inverters & MIG Welders

[Kathy]

Ben writes:
"Q:  How do you bend rod without losing the brittle flux?  (or was that
in a different thread?)"

Fluxed rod? Fluxed rod would be used for brazing or braze-welding of steel or
nonferrous metals. It would even be used for braze-welding cast iron. However,
copper coated steel alloy is the rod of choice for gas (fusion) welding of
steel. The difference in filler choice is based in the difference between fusion
welding (melting and intermixing of parent metals with or without filler added)
and joining by diffusion (braze-welding) of a lower melt temperature metal into
a higher melt temperature alloy by way of adhesion/dispersion, which is
essentially a temperature accelerated chemical intermingling.

The point for you to understand is that fusion welding is completely different
from braze-welding. You are far better off to start with fusion welding, alter
which braze-welding comes naturally. The learning process does not work nearly
so well the other way round.

Another trick to shorten the learning curve:
(1) Without worrying over forming a weld bead, sit down in a comfortable
position. Holding the torch in one hand, drape the whip over your shoulder,
leaving about 2" of slack in the lead.
(2) Ignite the torch and set a neutral flame, using it to heat a red hot spot on
the surface of steel sheet metal.
(3) Bring the flame and copper coated filler rod into close proximity (almost,
but not quite touching) one another, and inclined together at a sixty degree
inclusive angle, above a steel sheet (about 1/16" above the surface). Wait till
a drop of filler rod starts forming a weld bead on the steel sheet.
(4) Begin moving both flame and rod end in a dance around each other; the flame
describes a "U" around the rod, as the rod swings back and forth in a "C" within
the "U". As a bead forms, move the dance partners forward out of its way.

 Within twenty minuets, you will become proficient, and it then time to vary the
dance; begin shortening both the "U" into a "C" and reducing the rod's movement,
until it doesn't quite clear the flame. Gradually allow your attention to drift
from the dancing couple unto the weld bead they leave in their wake; slow the
pace and watch it bulge, then increase the pace until it narrows.

Do not allow boredom to stop your practice, but rest before you hand gets shaky.
One of the worst mistakes welding students make is practicing too long in one
position; once you get tired enough that your body no longer serves well, your
practice becomes an "unlearning" session.

As soon as you become proficient at flatwork, cut sections of pipe or tubing and
begin practicing vertical welding (up-hand and down-hand with the work placed at
various angles). There has been much written about out of position welding, most
of which is superfluous. Learn the dance thoroughly, and your two partners will
adapt with surprising speed to other positions. When carrying heavy beads up or
down-hand, the flame is aimed at a flatter angle, which quite naturally changes
in response to the needs created by your position on the pipe. As the work
changes from the vertical toward the horizontal position, your flame will start
shifting from a following position, drifting somewhat lower than the rod and
pointing upward as well as forward' the open end of the "U" or "C" will also
rotate from horizontal and facing forward to varying upward angles.

By the time the vertical and angled practice positions are exchanged for
vertical and horizontal welding, you have arrived. Welding practice is about
learning to understand the process more than about developing arm muscles.

Why learn pipe welding first, rather than taking the conventional rout of
working your way up from flat sheet in different positions? Would you rather
slog your way up a mountain or take the ski lift? Welding is taught from
simplest to "more advanced" techniques in welding schools because the students
are under considerable mental pressure, having to do with expected performance;
after all, their goal is certification. Also, from the instructor's viewpoint, a
culling process is going on; why waist a lot of instruction time on the
inevitable quitters? None of this applies to the self-taught welder. Therefore
why would he/she take the slow path? Any pipe welder can join flat plate in all
positions, but very few plate welders can handle pipe; add to this the fact that
pipe welding will teach mastery of the process much faster than working with
flat plate, and the question becomes "why waist time and money taking the slow
path?
Mikey


New Lessons in Welding (written during W W ll by the Lincoln Welding Co.) is a
good primer for anyone who wants to pick up the knack gas welding.
Mikey
 

"Whip"--a 12 foot length of 3/16" torch lead connected between an oxy-fuel torch
and larger diameter feed hoses. While commonly assumed to be employed to reduce
weight, its true value lies in its greater flexibility.
Mikey


-----Original Message-----
From: theforge-bounces at mailman.qth.net [mailto:theforge-bounces at mailman.qth.net]
On Behalf Of Ben Barrett
Sent: Tuesday, May 29, 2007 8:27 AM
To: Sponsored by ABANA
Subject: Re: [TheForge] Inverters & MIG Welders

I'm also a pretty new welder... I find that starting cold with my own
little 110vac harborFrinese box is about the hardest time for me.
Preheating with the torch (or forge) does seem to help that quite a
bit.  However, cold starts with a friend's 220vac (still not DC) are
much easier, in my experience.
I also have been spending some time with the OA torch, since a number
of elders suggested that would be the best way to *learn* about the
welding process, and that OA welding experience would transfer
ultimately to other forms.
I agree heartily about practising flipping your hood down; after even
just dozens of attempts, I got much better :)   ...and just time and
comfort.  I'm still more comfortable with the buzzbox than with the OA
torch,

Aubrey:  are you making small circles with the tip/puddle as you
proceed along the direction of the weld?  At first, I found myself
jumping around a lot, trying to retouch an area that was just cooling;
it seems much better to either go slower and get the puddle melted
into where you need it at first, or else stop & clean the half-good
weld before welding over it.... come to think of it, I'm guessing
others will clarify that half-good welds should be completely ground
away and re-done ;)
I'm beginning to spend enough time fussing with a few crappy welds, to
pay a lot more attention to getting it right [enough] the first
time...

Q:  How do you bend rod without losing the brittle flux?  (or was that
in a different thread?)

thanks y'all,

ben


On 5/29/07, Washington, Aubrey O. <awashington at ou.edu> wrote:
> Thanks for the advice and good discussion.  I've decided not to go the
inverter route.
>
> I spent some time over the long weekend playing with my new Millermatic 140
MIG.  It comes with a chart that suggests voltage and wire feed settings for
various wire and base metal combinations.  I'm starting to learn how to make
adjustments to improve penetration, reduce sputtering, etc.
>
> I used the MIG to weld up a pipe crucible to fit into my new propane forge
(which I build two weeks ago).  Since the metal was about 1/4", I beveled the
edge of the pipe to improve penetration.  The welds seem to be holding fine
after melting about 100 aluminum cans.  All in all, the welds looked much better
than anything I could have done with the AC arc welder and had adequate
penetration.
>
> Mikey, your comments about welding skill are interesting.  The auto darkening
hood did a lot to improve some of my stick welding problems; I start on target
and stick the rod less frequently.  But, I still make ugly welds with porosity
and slag inclusions.  Not blaming the tools, but would that improve some if I
had a DC welder (all else being equal)?  I know I need to improve my ability to
maintain a consistent arc length and travel speed.
>
> Aubrey
>
> ________________________________
>
> From: theforge-bounces at mailman.qth.net on behalf of Kathy
> Sent: Sat 5/26/2007 12:39 PM
> To: artgawk at thegrid.net; 'Sponsored by ABANA'
> Subject: RE: [TheForge] Inverters & MIG Welders
>
>
>
>
>
>
> Washington, Aubrey O. wrote:
> > Thanks, Terry.  But, I need something easier to use than my AC tombstone,
not
> harder.  I'm not a great welder.
>
> I have always had lousy "hand-eye" coordination, and vision problems to boot,
> but I was Top Gun in my welding class. There is a popular saying: "It's a poor
> workman who blames his tools." The truth of the matter is quite different; a
> workman is no better than his tools--and his understanding of them. Being a
top
> flight welder is about knowledge, and not about being Superman. Anyone can be
a
> great welder if he or she is given proper directions. To get those directions,
> we simply need to ask the right questions AND KEEP ON ASKING THEM UNTIL WE
> RECEIVE AN H-O-N-E-S-T ANSWER instead of the standard self congratulating BS.
> :-))) My personal favorite example of misdirection was a guy who tried to tell
> me that I couldn't learn to weld because my eyes were green, and "everyone
knows
> that only brown eyes are dark enough to protect you from the glare," leaving
no
> question in my mind as to why his eyes were brown.  Welding is not rocket
> science; it's more like ditch digging. Of course, after mastering it, we
should
> be sure to maintain the lies about "hand-eye" coordination, etc. when a boss
is
> trying to evaluate our worth.
>
> For instance, what are the two first stumbling points a welding student
> encounters?
> (1) They don't take the mere ten minuets practice holding the rod 1/4" from a
> target, while repeatedly flipping their hood down, which would insure that
they
> do well when they try actually tap starting the rod on a work piece. And so,
all
> further efforts are hampered. Even rods that are usually scratch started must
be
> tap started in some situations--ask any pipe welder just how important
absolute
> control when starting a weld is. Today, we have auto-darkening welding hoods,
> which make knowing how to "flip the hood" unnecessary. However, if you use
> auto-darkening welding hoods to replace that knowledge, you had better also
> install an ADC (auto-darken cartridge) in your sock hood too.
>
> (2) Novice welders have considerable trouble holding the rod steady while
> building up endurance. However, most of their troubles come from the
unconscious
> habit of gripping the rod holder tighter in response to nervousness generated
> during the learning curve. A heavy rubber band (the kind used as a marker on
> your local welding supply dealer's gas cylinders, hint, hint), or the
> installation of two snap buttons on the welding glove (try Harbor Freight for
a
> cheap set of installation tools), will help remind the student to grip the rod
> holder lightly, using the wrist to control movement NOT THE FINGERS. This
little
> trick can take months off your learning curve. On the down side, you will not
be
> able to explode an egg all over the walls and ceiling when someone sets it in
> you hand and says "squeeze it closed if you can" (your choice as to which is
the
> more important goal). As to building arm strength, professional welders use
aids
> like whips (light weight lengths of welding lead about 12 Ft. long with their
> own rod holder and end connector) when doing lots of overhead or vertical
work.
> They also bend welding rods into an "S" shape, and suspend the last few feet
of
> lead from them, or if no better opportunity presents itself, the lead is
draped
> over a shoulder, so that only a small part of its weight must be born by the
> crafty, lazy, welder type person :-)
>
> Everything else about welding has an easy and a hard way, including how well
you
> can see what you're doing. This one is a real biggy, yet it seems to be almost
> completely ignored by novice and professional alike.
> Mikey
> >
....
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