[TheForge] Inverters & MIG Welders

[Ben Barrett]

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
> >
....