|Cable Damascus Kukri
||[Apr. 20th, 2013|10:56 pm]
So, I made a cable damascus kukri.|
This is a knife I've been envisioning for years. To me, somehow, the combination of the pattern in welded cable just seemed to match the curves.
Pics and details behind the cut
A couple of years ago, I made the billet this was formed from. I had never made cable damascus before, so I made a few mistakes before figuring out how to make it work. While I've read of people taking apart the cable, wire by wire, cleaning it, and then reassembling, that just struck me as excessive. Ok, so one guy does not only that, but coats each wire with nickle before reassembling, and gets absolutely beautiful results, but I just couldn't see myself going to that level of effort.
That said, the basics are simple: soak in solvent to remove as much of the asphalt-like lubricant embedded in the cable, flux, heat and twist until the cable is nice and tight, and then get to welding heat and forge weld it into a solid billet. My personal technique is to forge weld the ends first, then twist, then weld up the rest.
Once welded, forge to shape. As with all damascus, to get the best pattern, forge thick then grind thin. On it's surface, the wires are pretty boring, pretty much just long straight lines. Closer to the center,it's much more active, so much so that some smiths cut the cable in half then weld it back together with the former core on the outside. Again, a bit too much effort for me, so I just forged it thick, then off to the grinder.
I decided on a convex grind, not as dramatic as a flat or concave (hollow) grind, but with more steel reinforcing the edge, there's less chance of edge damage, should this end up being a working knife. Stick tang, shouldered at the ricosso, nothing special.
And then I put it aside, for over a year. A couple of months ago, I picked it up again and finished the grinding and polishing.
For etching, I tried a few different reagents. Nital, or nitric acid in alcohol, gave an even grey patina, but not much pattern enhancement. Nitric in distilled water did better, but nothing special. Vinegar, while slow, brought out some of what I was looking for, but was slow and uneven. Finally I hit the jackpot with some "nickle black," which a vendor had said would do interesting things to pattern welded steel. A solution of selenous acid and some secret ingredients, it turned the blade black, and attacked the boundries between the wires much more aggressively than the wires themselves.
The thing is, the wires in cable is all the same type of steel--1085 more or less -- the only thing that will make a pattern stand out is the slight difference in carbon on the surface of the individual wires. Finding an acid that would attack that area differently from the inner area is a bit of a crap shoot, as a lot depends on your welding technique, variegates of the cable production, and so on.
Anyway, having gotten a decent pattern, I moved on to the handle. I'd already decided on an interesting wood I'd discovered, black palm, which isn't so much from a tree as from a large grass. The wood consists of long strands of black and tan fibers, and is notorious for being splintery, hard to work, and brittle. I'd bypassed some of these issues by slabbing up some into 1/2" pieces, then vacuum stabilizing it with diluted polyurethane (50% poly, 50% acetone). Still, it was not the easiest wood I've worked with, and I sometimes wished I'd gone with my 2nd choice of fiddleback maple.
To attach the handle to the blade, I hollowed out a channel in one slab, glued the two slabs together, then did the initial shaping. I used some leather as a spacer between the stainless steel guard and the black palm, and made a brass butt plate for the base. I used a high-temperature epoxy (good to 300F according to the manufacturer) for assembly, and peened the tang over the buttplate to hold it all together.
Final shaping of the handle was done with microplane files (wonderful things) and sandpaper, and the finish is four coats of polyurethane with a top coat of buffed wax.
Here are some pics. Full-size are available at http://blackanvil.livejournal.com/pics/catalog/1554