Sunday, July 14, 2013

How to Turn an Old Machete Blade into a Pig Knife

Around these parts you can find old machetes lying around if you know where to look.  These are blades that have seen hard use.  They’ve been sharpened thousands of times and the original blade contours have long since disappeared.  Many of them no longer have handle scales attached and in profile they look more like sabers than machetes.  You’ll find them in a barn or pickup bed or maybe even abandoned in the woods.  Most of them are rusted beyond repair and others snapped in two when people used them as crowbars.  Occasionally, you’ll find a couple or three you can breathe new life into if you’re willing to do a little work.  And perhaps I should tell you now that in a real and practical sense it’s probably not worth it.  Unless, of course, you’re a knife hack and can’t resist experimenting with steel no matter how much trouble involved.

I’ve got a stack of worn out and very much used machetes I’ve scrounged up over the years.  Most of them will probably remain relegated to the junk heap.  But now and then I’ll take one and toss it into the fire when I’m annealing some other piece of steel for a knife making project.  Most machetes are made from moderate level carbon steel like 1074-75 which is easy to sharpen and tends to hold a good edge.  It’s also good steel for whacking brush as is 1060 carbon steel and 5160 spring steel.  I’ve seen a few machetes made from 1040 steel but I’m not keen on those.  That’s an easy steel to use in economical mass production but I’ve never encountered one that holds an edge for very long.  Likewise, I’m no fan of the newer stainless steel machetes.  They don’t hold up like carbon steel models.

If you anneal an old machete blade you are likely to have some warpage since the blade is usually only about 1.5-2.0 millimeters thick.  Under the high heat of annealing the thin blade will bend somewhat.  But since the blades are thin you can easily straighten them in the annealed state.  The reason I anneal these old machetes is because I want to reheat-treat the blade afterward in order to bring up the hardness.  Most machetes are tempered in a low range 48-54 Rc to keep the blade from snapping when chopping.  But I cut the blades down to about 7 ½ inches long and therefore they will not be used for chopping but instead for things like skinning or slicing through clumps of nopal (prickly pear) cactus.  It just makes for a neat little knife that has a bit more robustness than your typical Mora-style blade.

The two knives pictured were hafted with a piece of alder wood.  I pinned the scales with nails and added strength with 5-minute epoxy.  Nothing expensive in this project since these are knockabout knives used in woods roaming and general chores.  They do, however, make excellent pig knives after you’ve taken a wild hog with your bow, rifle or pistol.  A wild hog is a lot more than gristle, muscle and bone.  The hair is quite bristly—almost like a wire brush—and requires a blade that can cut through that spike-like carpet.

I bring the temper up to about 57 Rc and that’s sufficient for dressing out hogs.  When you skin, gut and bone a wild hog you’ve got some work on your hands if the beast is anything over a couple hundred pounds.  I find these little rejuvenated machetes turned hunting knives a practical solution.  They’re lightweight and make for easy packing.  I usually carry at least three knives when I’m out after hogs.  I don’t want to spend time sharpening a knife when field dressing.  When a blade gets tired I switch to another and carry on.  I’ll show you some pictures of the other hog knives I use in a future post.