On Mon, 23 Jan 1995, Jeffrey J. Griglack wrote:
> First, someone asked me to let them know how well the Eastwood
> Spotweld Cutter works. I can now say that it seems to work pretty
> well. They say you can just center punch the weld, but I have had
> better results with drilling the pilot point a little deeper. I am
> left with a small "button" of metal where the weld was. Going is a
> little slow, but the result is worth it when one of the pieces is to
> be saved.
>
Lot of options and questions about cutting spot welds deleted.
> Those are the options as I see it. I know a body man who works cheap,
> so I might give him a call. Any suggestions??
>
I cut a whole bunch of spot welds when rebuilding Kermit. I tried the
Eastwood spot weld cutter, but I must have overheated and dulled mine
almost immediately because it was unacceptably slow.
I gave up on the spot weld cutter and began buying 3/16 inch drills by the
dozen, and just drilling half way or all the way through the center of the
spot welds. The trick is to locate the weld as precisely as possible, so
you can drill the center. Then, depending on what you are saving, either
drill all the way through, or just enough to go through the top layer of
metal.
That should almost completely eliminate the weld, but typically it still
needs to be broken apart, and this requires wedging something between the
layers of metal. I special ordered a "floor chisel" which proved useless
when it finally arrived--it was so thick it generally distorted the
daylights out of the panel I wanted to save, so I had to do a lot of
repair work on the saved panel after I had broken the welds. I eventually
settled on Hyde brand putty knives. They make a flexible one and a stiff
one. The stiff one is much thinner than any chisel you can buy, the blade
(tang) runs all the way through the handle so you can bang on the handle
with a hammer without breaking the handle, and the blade is just stiff
enough that it does not flex when you beat on the handle. These proved
wonderful--I went through a half dozen of them. They would slip between
the two sheets of metal causing minimal distortion, and cut rather cleanly
any remaining fused metal.
You can, of course, be more certain you eliminate all of a weld if you
use a bigger drill. I stayed with 3/16 drills because larger holes take
longer to drill and are more of a problem to fill later in the panel you
want to keep. 3/16 holes are almost exactly right for plug welding
later, so at the same time you are eliminating the old weld you are often
making a hole you can use later to attach a new panel.
When you have easy access to a panel you don't care about saving, one
solution is to use a disk grinder with a #36 open grit sanding disk or a
conventional grinding disk, and just grind away until the panel you don't
want is gone. As the panel you are removing gets thin, it will be heated
more and more by the grinding, and the spot welds will show a different
color. This approach is slow but easy and if you stop just as soon as one
layer is gone, it probably disturbs the piece you are saving less than any
other means of removal.
For the ticklish spots that you cannot get at with a drill or grinder,
try a die grinder with a round carbide bit roughly 1/4 inch in diameter,
and just grind away the center of the spot weld from one side.
Hope this helps.
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
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