Spring Sharpening

With the arrival of warm weather my grass has redoubled its effort to make my yard an uneven carpet of green.  Before getting the lawn mower out I needed to resharpen the blade.

I’ve stopped taking it to a lawn or garden center and getting the blade resharpened.  I bought a little attachment for my Dremel tool.  The attachment screws on to the front of the tool and come with a special diameter grinding stone.  A guide helps me hold the blade angle and lets me grind out the really dull and damaged

areas. 

Start your sharpening!

 On my electric lawn mower the blade rotates at 3600 times a minute.  A rounded edge will cut the grass by tearing it, but cleanly cut blades make for a better lawn.  Better looking grass without significantly increasing my work load is my goal, so sharpening the blade makes sense.

I clamp the blade down on a sheet of plywood and run the Dremel grinding stone over the old edge several times until the old discoloration is gone and so are the majority of nicks and gouges in the edge.  I use the plastic guide to hold the angle, but perfection isn’t required.  A fine dry stone pulls the wire edge off the other side.  I should mention my mower blade is a classic chisel grind.  I test the sharpness by shaving the edge of the plywood board I use as a work station.

The last step before reinstalling the blade is to check the balance.   If one side of the blade was significantly heavier, the mower would vibrate and damage itself, perhaps even break a blade.  The heavy side just gets another pass and a second balance check.  Repeat as required.

Since I was in sharpening mode I got out my Ken Onion Work Sharp blade grinder and sharpened my hatchet. 

As you know I recently discovered my SOG camp hatchet was extremely dull but luckily my friend Derrick brought his Gerber hatchet.  Having a fire in the fireplace as part of the evening’s entertainment and as a back-up to winter storm power failures is a nice luxury.  The price you pay for this is splitting wood into suitable burning size.  A sharp hatchet is required and mine needed a good sharpening. 

Every fire deserves a sharp hatchet

 I selected the course belt and an angle of 25 degrees as a starting place and ran a black marker pen over the edge.  The marker helps me see what I’m doing and where I’m taking metal off.   A couple of passes and I had removed the entire marker pen.  I flipped it over and did that side. 

Before sharpening, note nicks in blade

The blade looked good so I changed to a medium grit.  That took a little more off and I was satisfied.  But how you really tell if your axe is sharp?

I decided performance was the only way.  I grabbed a section of a landscaping tie and a length of pine 2X4 and tried it out.  I was less than impressed.

The hatchet didn’t cut the wood fibers, but crushed them.  Definitely not sharp.  I changed the angle to 10 degrees and repeated the process.  This angle worked better. 

bye-bye nicks!

While I was touching up the edge I noticed the cutting edge wasn’t centered in the blade’s secondary bevel.  This typically happens when one side of a blade is sharpened more than the other.  I played with it for a while and discovered one side the bevel is flat ground while the other is slightly convex.  This bevel asymmetry is the cause for the non-centered edge.

I worked on the edge a bit more and called it finished.  It’s not perfect, but it’s sharper than it was.  Chopping pine boards may not be the best material to judge hatchet performance.  I’ll look around for actual logs to try it out.

Stay Sharp in 2016

New Year’s Day calls for a roasting pan full of pork, smoked sausage and sauerkraut at my mother-in-law’s house. The food preparation is relatively simple, but conflicts do arise. 

I am convinced that my martial arts instructor got it wrong.  He once told us the Chinese ideogram for trouble was two women under the same roof.  He’s wrong.  It’s an elderly mother and her daughter under the same roof.

Despite that, everything went fine except for the knives.  I have never seen two kitchen knives so dull.  Fortunately, I had my Spyderco Sharpmaker available.  Even more fortunately, I own a pair of coarse diamond sharpening rods.

The silver diamond rod and a dull santoku

Spyderco has made diamond rods for a number of years, but the cost for diamond-impregnated rods was above and beyond affordable.  Recently breakthroughs have brought the cost down so mere mortals like myself can afford them.  A retail cost of $80 for two rods isn’t terrible.  They also make a cubic boron nitride for the same price.  

The key, Spyderco’s Joyce Laituri told me, is not to bear down hard, but to let the diamonds do the work.  It only took a few swipes on each side to get the knife which wouldn’t tear paper to one that cut paper.

I've worked through the medium and ended with the white fine stone.  Spyderco makes an extra fine, but I suspect I really don't need it.

From there it’s working through the dark medium stones and the white fine stones.  I would suggest not always starting the sharpening stroke at the back of the edge or choil, but also at the knife tip.  I find that gets a better edge faster.

Years ago I was told about another knifemaker who used his Spyderco Sharpmaker backwards.  He started down at the bottom of the V formed by the two stones and brought his knife upward as well as towards himself.  

This makes sense.  You want to draw the wire edge, where the real sharpness is, outward from the blade.  When you strop an edge on leather or the cardboard backing of a paper pad, that’s what you are doing.

You can do the same thing with a fine stone too!

That edge doesn't have a micro-serration.  It's just badly damaged.  (It's a crappy photo, hard to hold the knife at the right angle and camera.)

The little santoku knife was dull, but the little Spyderco paring knife was beyond dull.  Holding the knife upside down and staring where the edge should have been was unusual.  I’ve never seen an edge that looks like tiny polished diamonds before.  Fortunately, the diamond rods took the chips and gouges out right away and let me work to the fine stones without too much trouble.

You see the side of the blade, but the not the edge.  It isn't because I've sharpened to a sub-atomic edge, but because its sharpen enough to come to an edge smaller than the resolution of the eye. 

I’ve always enjoyed sharpening knives.  There is a rhythm that seems to resonate with me.  It’s peaceful, calming work.  I stand or sit and under my finger pressure steel turns into an edge, one of man’s oldest and most important tools.  There is a connection between me and first person who wondered if they could make a favorite tool work again.  I like that.

Have a Happy and Sharp New Year in 2016!

Spyderco 204D a pair of diamond rods or 204CBN a pair of cubic boron nitride rods:  $58 plus shipping  Contact me.  Searcher12@gmail.com