Hello all,
I decided to try my hand at making some damascus-style pattern welded
knife blanks, and it's working more or less all right. Just a couple
of quick questions for those of you who have done this, if you have
the time to answer.
First off, what I'm doing, at least for this first try, is using an
old chainsaw blade that was bead-blasted and then soaked in acetone to
get it as clean as possible. I then had a friend of mine fuse it
together and weld it to a handle to make it a little easier to work
for. So far, so good. I've got 20 mule team borax for flux, and
while I've heard that anhydrous borax is better, this stuff seems
fine, and is doing the job well enough. I'm doing all the heating in
a forced air propane forge, and have missed a couple of welds, but
about 90% of them seem to be pretty good.
All that being said, here are the questions I have been asking myself
while working on this. The first is a matter of flux- being a little
less than completely confident about my forge welding technique, I've
been putting about a tablespoon of borax on each time I put the piece
back in the forge. As you might imagine, this has made a real mess of
the firebricks I've got on the bottom of the chamber. Any clue as to
how much flux I *should* be using? It's working, but I get the
feeling I'm probably overdoing it a bit.
The second is a matter of gas setting- I can't for the life of me
remember if I want more or less oxygen for the best weld. So far,
I've been running the mix really gas rich, with a low stream of forced
air. Again, it seems to be working all right, it's just a matter of
figuring out if I'm making more work than necessary for myself.
Third is dealing with small cracks. At this point, after about 3
folds and maybe 12 or 13 heats, it's looking pretty good- but there
are one or two areas where there is a small crack on the surface that
is apparently a spot where the weld did not take fully, as they look
like the partial outline of a chain link. Any chance that just
continuing to flux the blank while drawing it out will close these up,
or do I need to grind those out before proceeding? (they're visible,
but not very deep)
And last, but not least, is bringing out the pattern- it'll be a few
days before I really need to start thinking about that, but it never
hurts to plan ahead. I have a quart of ferric chloride that I've been
playing with by etching copper and brass with it, and I more or less
intend to etch the finished blade with that- unless there is a good
reason not to. Any opinions on whether this will work better than
muriatic acid from the hardware store? I'm also wondering if the etch
needs to be done before or after heat-treating the blade- a lot of the
pattern-welded blades have a striking black and silver contrast, and I
have no idea if this is a matter of heating it after etching, and then
poli****ng the high points, or if the etch itself makes this happen.
Any hints, tips or tricks would be greatly appreciated. I'm sure this
one is going to turn out to be ok in the end, but it never hurts to
get advice whenever possible.
Thanks!
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