My sincere thanks to R. Cinq Mars, for suggesting that we work on this
project, and for his assistance in filming and photographing a good chunk of the
footage...
Similarly Scott (Jonesy) Jones for writing the Excellently informative
"The absolute Cheapskates Way to Make Knives - Released as an open Source
Document in PDF format... It's the efforts of the Jonesy's of this world that
will make navigating the economic uncertainty of these times less troublesome...
After spending close to an hour flipping through as many styles, shapes and
lengths of Machete type blade designs with Google Images, I drafted the amalgam
shown below and call it the "Bush-Master", initially I toyed with the
Name "Bush-Master 2009", but thought that might prove limiting in the
least and truly dated by this time next year...
The over-all length is limited by the section of spring steel that you may have available. The hand grip was sized to my hands and based on 1/2" wooden
grips on either side of the 1/4" thick steel.
Rather than get side-tracked with building a wood fired
"Blade-Forge", we opted to just use the "Master-Blaster"
melting furnace...
In my mind I just want to see how doable this is, and if I'd ever want to do
it again, so time & materials have near zero hourly or capital allocation,
also because this is an un-scheduled project.
The furnace performs like a Champ, and once fully fired after 20 minutes or
so, both R.C-M and I were hustling to keep-up to the fast cycle times between
beating the metal and bringing it up to the heat that made it workable.
In the video, disregard the opening scenes of "Plasma-Cutting" the
cold spring steel, an angle grinder with a thin (1/32nd" thin) Walter
"Zip-Cut Disk" is just as fast. You'd think that those pricks at
Walter Corp would ship me a case of Zip-Cuts for all the free advertisings I
give them... But if you have a product that is un-surpassed in quality, I guess
you can be aloof to the toiling minions that consume your wares...
At this phase we're just figuring out how hot is hot enough to work the
metal, and it has to be brought flat, as it originally had the characteristic
curvature of a truck Leaf-Spring.
An anvil is approximated by the 1" thick disk of steel that is fastened
to a block of green maple cut just weeks before.
It took considerably longer to figure out the best way to hold the spring
and to work fast before the metal cooled, than the actual working of the leaf to
a "Flat Stock".
The pattern is transferred to the flat-stock with a stub of soap-stone...
If we had time to burn we would have "Annealed" the Flat-Stock
prior to cutting to shape, and we may have been able to do both knives with one
Zip-Cut in the grinder. But we opted to just air cool the blades and had a bite
to eat...
Curiously R. C-M ended-up with all the images of the blade-cutting, as we
traded-off cameras in quick succession of each step and I wanted to get a good
look at the Sony he'd brought out and used his camera for many of the steps I'd
wanted to use of his knife (all is not lost as there is reasonable footage in
the video below of both knives up to the step of
"Heat-Treating/Tempering"...)
Where we did Fuck-Up, was after we pounded the basic blade shapes out of the
rough-cut patterns, we quenched the blades in snow and ice, which proved to be
the worst possible thing to do...
Every step from surface grinding to shaping, honing and trying to drill
holes for the handles was a nightmare.
If we'd shut-down the oil-burner and left the blades to cool in the
refractory chamber over the course of the evening, they would have been much
easier to work the following day. On this point alone I want to make another
knife just to prove-out the theory that Annealing is a required step.
Another 2 (two) hours of work will be invested into this blank before it
will be ready for Heat and handles...
You saw the diagram at the top, and you can see the the blade took a marked
curve under the force of the blows delivered in the thinning and shaping of the
leading edge of the blade.
Another missing image is that of "rough-cutting" the handle,
drilling the holes, and registering the holes to the handle...
Here the shaped, sharpened and drilled blade is set into an oven pre-heated
to 400F for a period of 2 hours.
The blade is removed and quenched into cold water immediately upon removal
from the stove.
The colour and hue of the steel can be co-related to a semi subjective
temperature chart that demarcates the range of temps such that;
- light yellow thru straw are in the low to mid 400F range while;
- purples and blues are higher-up approaching 550 to 600F (depending on
who's chart you reference)
Of the 6,000 hits on the search query below, you'll quickly adopt a
statistical average that is fine for this grade of work...
The reason that metallurgy concerns itself with the colours and
co-responding temperatures is related to the changes that the micro-crystalline
structure of the steel under-goes, called phase-states or changes...
If you want to dedicate weeks or even months to this study, I highly
recommend B.J. Moniz 554pg tome "Metallurgy 3rd Edition" published by
ATP - American Technical Publishers, and with a title as enticing as that you
just know it's going to be a "page-turner"...
The handle is cut from a 1" slab of white oak that was recovered from a
1926 Barn (dropped last year).
The pre-drilled handle is ripped into half as closely as possible, but this
is not over critical.
The milled faces of the wood are placed inward toward the steel for as flat
and snug a fit as possible.
The handles are shaped and smoothed with a Walter "Flap-Disk" in
minutes, while the zinc-plated fixturing hardware is recessed and ground flush
for a secure grip.
The blade surface is hand sanded and polished with compound to remove the
tinting that resulted from the "Tempering" step. I opted not to use
any power tools for fear of building any heat-up on the edge of the blade and
again loosing the temper.
As shown above the blade is honed with a stone and the file has to have
considerable pressure exerted to bite the steel.
The Bush-master proved his metal on a particularly bright warm day in siting
this ground-blind on the edge of a pond.
In closing, this was a great little project & I'm sold, over the next
couple of months I can see building a dedicated forge to capitalize on wood and
charcoal type fuels, rather than the exotic Diesel that I have to go into
town for ... and try not to think about the cost exacted to make it available to
me...
The patchwork of images above are brought to life in full-motion video and
stunning stereo sound at the link below...
