Sunday, May 19, 2013

SCARY Sharp

The second law of homestead thermodynamics goes something like 'sharp things will always tend to become dull.'  This is especially true if the sharp thing is a blade on a tool you need for the next task on your list.  We we were reading about ways to sharpen blades a while back, and since blade sharpening one of the skills we wanted to develop this year, we figured we should probably get around to it (it is almost June, after all).

The best description we've come across of how to sharpen a (flat) blade is this tale of the Scary Sharp method.  Even if you don't have any blades to sharpen, it's worth a read.  Make sure you're not drinking anything at the time, because you might accidentally spit it out.  Basically, the technique involves a hard, flat surface (like a piece of glass) and increasingly fine grades of sandpaper.  Pretty simple, eh?  The method works best with straight (as opposed to beveled) blades, but it was good enough to get a beveled hunting knife back to factory sharp last fall. (Not quite sharp enough to shave, though, which was another one of our goals).  So we decided to try the same technique on another knife with a flatter blade in hopes of being able to rediscover Jake's face!

*NOTE: We could not be considered experts in blade sharpening by any stretch of the imagination.  We are simply chronicling our experiments in learning to sharpen blades proficiently.  If you're searching for a way to sharpen your own blades, please don't use us as your only source of information. :-)


Here are our materials and our setup.  Sandpaper: 400, 600, 800, 1000, 1500, and 2000 grit.  A pane of glass from an old window (came with the windows we got for free for the coldframe), and a knife.  The knife is a one-edge straight blade, stainless steel (the blade style is more visible in the next picture).

Here it is after the 400 grit.  We sanded all three faces: back, front, and cutting edge.  Since the cutting edge had coarse marks in it from the factory grind, this grade of sandpaper took the longest (about 15 minutes).  We wanted to get it to the point where all we could see were the scratches from the 400 grit sandpaper.  When sanding the cutting edge, it's very important to keep a consistent angle between the knife and the sandpaper.

After the 600 grit.  It might not look much different, but for alternating grades of sandpaper, we try to use a different sanding pattern.  For one grade, we move the knife in straight lines back and forth (parallel to the handle for the front and back, and perpendicular to the handle for the cutting edge); for the next grade we move the knife in a circular pattern.  That way it's easier to see when scratches from the current grade of sandpaper have erased scratches from the lower grit.

After the 800 grit.  You know we're getting serious now because the sandpaper has switched to black.

The 1000 and 1500 grit looked pretty much the same as the 800 grit, so we skipped to the picture of the 2000 grit, where we've gotten a sort of mirror finish on the blade (reflecting the sandpaper box on the flat part).  Must be sharp now!

The classic test to see how sharp it is (other than cutting a piece of newspaper or something more reasonable) is to see if the blade will shave off a few arm or leg hairs.  After all, the closest piece of newspaper was like, ten feet away.  Looks like it will take off some leg hairs, no problem!  (Edit: Katie says, "Jacob!" [uh-oh...she only calls me that when I'm in big trouble.] "Did you shave off a random patch of extremity hair just to see how sharp your knife was...again?!"  Response: "Yes, but this time it will still be covered by my shorts, so I won't have to wear long-sleeve shirts for two weeks!"  Re-response: *eye rolling.*)  Can't wait to see how it works on facial hair!

Tune back in on Thursday to find out if the newly sharpened knife works for shaving facial hair!

Do you have a favorite technique for getting knife blades razor-sharp?  What is your preferred test of knife sharpness?  Tell us about it in the comments section below! (so Jake can stop having random hairless patches on his arms and legs!)






3 comments:

  1. Sometimes I wonder why Katie EVER lets you out of her sight. And since I'm reading from most recent to least recent on your blog posts, I have to say... seriously? THAT'S the knife you chose to later shave your face? Those aren't even good at cutting food! Can you at least pick a proper knife next time?

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    1. Well...there was a little bit of reasoning that went into selection of the knife. Mainly we picked it because the cutting edge comes together from two straight edges (one of which is the whole back side of the knife) and isn't beveled at all. That means it takes a lot less skill to sharpen by this method. It's now quite a bit sharper than the other knives we use to cut food, but many other blades that are designed to shave faces don't cut food well, either. Unless you count something like a potato peeler.

      But it's true that Katie has been more suspicious of my activities since these two posts. :-)

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  2. These are really amazing knives.I also like all the functions and blade of this knife.
    OTF Blades

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