Grant,
The torch - quench method has been quite successful when I tell myself
"that's much better". I too have tried to keep going for even more
improvement and then found myself overdoing it. That's why my advice is to
go slowly in small spots. You're right though, I forgot to caution Deve to
Stop BEFORE it's perfect.
Dick
1959 Apache 1 ton - "Chief"
----- Original Message -----
From: "Grant Galbraith" <trks@javanet.com>
To: "Marlene Rzepkowski" <mrzepkow@rochester.rr.com>
Cc: "Deve Krehbiel" <dkrehbiel@kscable.com>; <oletrucks@autox.team.net>
Sent: Thursday, May 11, 2000 11:10 PM
Subject: Re: [oletrucks] Welding Help Needed!
> Dick,
> I've tried the torch-quench method of shinkage you describe, not on
weld
> warpage but on stretched areas from large dents or on a oil canned roof or
bed
> sides. While I've found it will shrink metal, learning how much and where
has
> prooved elusive for me. Frequently I will make an improvment but then go
too
> much trying to get it better. What kind of luck have you had?
>
> Grant
> 50 Chevy 3100
> 52 GMC 150
>
> Marlene Rzepkowski wrote:
>
> > Deve,
> > You've been given great advice so far on how to do it better next time,
this
> > note tries a little twist on how to save it this time without a total
re-do.
> >
> > First, warping is caused because the molecules in the metal expand on
one
> > side (The top side where you were welding) more than on the other and
don't
> > get reassembled back into their original place as they slowly cool. To
> > counteract the "set" that the steel has taken, you can apply some heat
from
> > the back side of the original weld if you can get at the back side. If
you
> > can only get at the top side, then try the following.
> >
> > If you have an Oxy-Acetylene torch (I suppose a propane torch could
also
> > be used but I have no experience with propane for what follows) you can
> > heat a small spot, then quench with cold water and the steel on the top
> > will suddenly cool quicker than the steel below giving you the opposite
> > direction of warp from the slowly cooled weld joint. Do this in small
> > spots, almost like tack welding, no more than an inch at a time. I use
a
> > Rag dipped in cold water and still dripping profusely to quench the hot
spot
> > I create. This also works for tightening up sheet metal in places that
tend
> > to "oil can". You can heat the bulge, quench it to shrink the top side
> > metal and "tighten up" an area that is "oil canning".
> >
> > The suggestion of using cold air to cool a weld as you go is very
similar to
> > this. If the weld spot is cooled with air right after the weld is
completed
> > you can better equalize top and bottom cooling and end up with less
warping.
> > Try these techniques on a scrap piece to see the effects. Heat is a
pretty
> > amazing force in dealing with sheet metal! Good Luck.
> >
> > Dick,
> > 1959 1 ton Apache - "Chief"
> >
> > ----- Original Message -----
> > From: "Deve Krehbiel" <dkrehbiel@kscable.com>
> > To: <oletrucks@autox.team.net>
> > Sent: Thursday, May 11, 2000 9:55 AM
> > Subject: Re: [oletrucks] Welding Help Needed!
> >
> > > It was a flanged weld that warped so badly. I flanged it and then left
> > about
> > > a 1/8" gap so the weld could sit low in the seam making it easier to
> > grind.
> > > The location is clear across the inside bottom of the door (about 4
inches
> > > up).. no strength there. I will try the 80/20 mix, and spot weld the
whole
> > > thing alternating around to reduce heat. I am using .025 wire. I will
also
> > > try further reducing the voltage and see if that wont help.
> > >
> > > A few people (including my local professional welder) said to INCREASE
the
> > > voltage and run the bead faster. I do not like this!! To make that
weld
> > with
> > > the increased voltage, I would have to VERY quickly zip across that
seam
> > and
> > > I cant imagine how its even possible to get a decent result. I tried.
All
> > I
> > > get is holes in the metal. Its very frustrating and as an electronics
tech
> > > for years, soldering wasnt anywhere near this hard. Same principle tho
and
> > > to me, you need just enough heat. More than that is wasted. I am
hoping I
> > > can reduce the voltage to just get good penetration and then work
slower
> > and
> > > more accurately.
> > >
> > > If I use a hammer and dolly, I have to put the dolly inside the door
panel
> > > and hit it from above.. exactly backwards from what it really needs.
The
> > > warpage is concave and needs pounded OUT. I will try that anyway and
see
> > > what happens. I am pretty sure tho I will be cutting it all out and
> > redoing
> > > the job. Good lesson learned anyway. And it WAS my first attempt at
> > welding
> > > sheet metal.
> > >
> > > Thanks everyone for the encouragement and advice. Please keep it
coming!
> > >
> > > Deve Krehbiel
> > > Hesston, Kansas
> > > 1950 3100 * 1949 3600
> > > www.speedprint.com/Deves50/index.html
> > >
> > >
> > > oletrucks is devoted to Chevy and GM trucks built between 1941 and
1959
> > >
> >
> > oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>
>
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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