Thursday, August 25, 2016

How to sharpen a double hollow ground bassoon reed knife

How can you tell if your bassoon reed knife needs sharpening?  Just drop the blade, sharp side down, onto your thumb nail.  If it catches, the blade is sharp enough.  If it just glides smoothly on your nail, then it's too dull to function optimally.

The following instructions were presented to me by the late Norman Herzberg who was widely known for his Los Angeles studio work, his revolutionary reed making concepts and tool production, and of course his legendary teaching.

These instructions apply to the double hollow ground style knife, which is probably the easiest type of knife to sharpen.

Mr. Herzberg recommended using a Norton Crystolon Combination Oilstone:
Norton Crystolon Combination Oilstone, Fine/Coarse, 1 x 2 x 8"

Being an oilstone, it must be oiled before each use.  Norton sells oil for this very purpose.  It's actually a light mineral oil:

Image result for norton oil for sharpening stone
If your knife is in really bad shape, begin with the rough side of the sharpening stone.  (An oboist reading this post might react with could a double reed player possibly be using a knife in really bad shape?   Well, bassoonists are generally much less religious about knife-sharpening than oboists, and for good reason.  For one thing, oboists are dealing with harder cane.  Oboists need a very sharp knife for precise cutting.  On the other hand, bassoonists often run into problems with accidental gouging and nicking of the cane with a very sharp knife.  Some bassoonists, according to rumor, never sharpen their knives.  My opinion is that bassoon knives should be kept reasonably sharp, passing the above-mentioned thumb nail test, at all times.)

First ensure that your stone is abutting a wall or some sort of stable object so that the stone won't move as you push the knife from the bottom to the top of the stone.  (For pushing down from top to bottom, you'll use your hand to hold the stone in place.)

Make sure that the sharpening stone is clean and dust-free before oil is applied.  I always store my sharpening stone inside of a container so that it doesn't become dusty.  Oil the stone by placing 3 drops of oil evenly spaced on the sharpening stone.
Evenly distribute 3 drops of oil on the surface of the stone.

Then smear the oil over the stone, covering it evenly.
The 3 drops of oil have been well-smeared evenly over the surface of this stone.

Start with the knife at the bottom of the stone, with the knife blade at approximately a 45 degree angle across the stone.  First lay the knife flat:

Then lift the back of the knife 1/8 inch.  That's the angle you'll maintain while sharpening

Lift the back (the thick side as opposed to the thin cutting edge) of the blade 1/8" up off of the surface of the stone.

Begin by pushing the knife up to the top of the stone.  Push into the edge of the knife.  After reaching the top of the stone, flip the knife over, then beginning at the top of the stone, push back down to the bottom of the stone.  Keep the knife rigid at all times, with the back raised 1/8 inch.  Don't roll the knife; keep it rigid.  Push into the edge you're sharpening.
Pushing the knife down from the top of the stone to the bottom
Repeat this routine a few times, then test the sharpness of the blade by dropping it onto your thumb nail.  If it catches, you're done.  If you began with a really dull knife and used the rough side of the stone first, then you'll be ready to flip the stone over to the fine side after maybe 10 or 20 swipes up and down.  Repeat the routine using the fine side.  Don't forget to oil this side also!  Then test the knife after using the fine side.

If your knife was already in decent shape, then probably only a couple of strokes on the fine side of the stone are needed.  Never use the stone without oiling it first!

Mr. Herzberg also mentioned that a hard Arkansas stone may be used. 

If you're one of those bassoonists who doesn't worry much about the sharpness of your knife, give this a try.  Chances are you'll convert!


1 comment:

homesteadorgus said...

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