"Grant Erwin" wrote in message
...
Jim Levie wrote:
On Mon, 20 Dec 2004 15:09:24 -0800, Grant Erwin wrote:


I'm finally getting back around to fixing up my little die filer. Its
chuck is pretty munged after years of having files jammed into it, and
it
doesn't work right anymore (i.e. doesn't hold the file parallel with the
shaft). I figure I'll mill away the "fixed jaw" and make a hardened shim
and glue it on. There will be little stress on the glue joint as it will
be held in compression, but there will be some. I'll be gluing a ground
surface to a milled one. Would cyanoacrylate (superglue) be the right
stuff to use?


Seems to me that silver soldering and quenching the shim would work
better. Either that of build up the worn jaw with a hardfacing rod and
grind down to finish shape.


Nope, don't want to monkey with the original paint. - GWE

If you want compression strength, a good grade of epoxy (not hardware-store
stuff) will give you around 4,000 psi or, if it's 100% solids, a little
more. Cyanoacrylate is a fraction of that, and its adhesion isn't nearly as
good as properly applied epoxy. One-part polyurethane (Gorilla Glue) is
somewhere in between.

I don't think you need a lot of compression strength for that job.
Personally, I'd soft-solder it and screw the paint (around 5,000 - 7,000 psi
compression, and good adhesion). But my second choice would be an
aluminum-filled epoxy. I think that's what JB Weld is, but I've never used
the stuff. The tensile strength of al-filled epoxy is questionable but its
adhesion strength is good, if you know how to apply adhesive to metals (a
long story, for another day). But its compression strength may be somewhat
higher than unfilled epoxy. Anyway, industrial-grade aluminum-filled epoxies
can run up to 6,000 psi or so compression.

My choice for ease and (probably) perfectly acceptable performance would be
polyurethane. It covers a lot of sins, partly because it's flexible and
partly because it has excellent adhesive strength.

--
Ed Huntress