welding (was: Tranny woes)

[amalventano at sc.rr.com (Allyn)]

got any quick notes from that class... for say... mig+gas?
i havent been able to find a good general guide as to adjusting settings
(current and feed rate), as well as good techniques to use when welding from
all angles (around seams of joining tubular steel sections together).

Al

----- Original Message ----- 
From: "T. Reed" <treed2@wsu.edu>
To: "Nate Mellom" <bronson@inwave.com>
Cc: "Allyn" <amalventano@sc.rr.com>; "Scirocco list"
<scirocco-l@scirocco.org>
Sent: Friday, December 12, 2003 3:24 PM
Subject: welding (was: Tranny woes)


> On Thu, 11 Dec 2003, Nate Mellom wrote:
>
> > No worries about the weld failing under torque?
> >
>
> I think it's a common misconception that welds fail frequently.
>
> I took a welding class this past summer and the instructor really knew
> what he was doing; he was an ARTIST when it came to welds and he had all
> the knowledge, equipment, etc. He had years of experience and his own
> company was making big money on a variety of special projects he was doing
> for various companies and affluent individuals.
>
> Anyway, I had just welded two plates together with Oxy-Acetylene and had
> them in a vice and was bending them back and forth trying (unsuccessfully)
> to break the weld. He asked me what I was doing and I explained. Then he
> told me that -good- welds (like the one I was trying to break) are as
> strong as or stronger than the metal around them. In fact the plates I had
> in the vice were bending next to the weld, not at it.
>
> I think a lot of random boobs in their garage with $50 welders try to weld
> things and utterly fail to make a good weld; succeeding only at joining
> the two pieces just enough so that they stay together. Then the "weld"
> breaks and they come to the conclusion that welds are weak.
>
> It's important to have the proper current (too little and you will only
> succeed at joining the outermost shell), the proper wire feed rate,
> shielding gas if you don't use flux-core wire, the proper wire type for
> the materials you're joining, AND good weld technique. If any one of
> these isn't right, you may get a crappy weld that may or may not hold up.
>
> When you're welding steel (say, spider gears in a differential), assuming
> you're using a monstrous machine with enough current, you should be able
> to turn the whole cluster of gears in to one solid piece of steel that
> will (essentially) never break. It's not like soldering when you're
> joining things with an intermediate metal. The filler metal is generally
> the same (or damn close) to the materials you're welding together. The
> whole area gets molten and joins together in to one piece. Its like the
> instructor said when somebody welded something together crooked and was
> trying to put an arc on it while pulling it apart: "that's not coming
> apart! go use the plasma cutter"
>
> -Toby
>
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