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["del stubbs" <pinewoodel@hotmail.com>]

Here is a rough draft of an article I had started for Nafex Pomona last 
March on grafting knife sharpening and use.   Have a read anyone, write back 
what needs clarifying, what you disagree with, whatever, help me make this a 
functional useful article. thanks, Del Stubbs

" Having just finished a couple hundred whip and tongue grafts, as well as 
teaching a woodcarving course - I have been thinking about  parallels 
between knife woodcarving and knife grafting.
1. Don't do the normal action one uses in the kitchen with a paring knife - 
of squeezing the thumb and hand together to get the knife to move. This 
endangers the thumb, and is not a particularly flat movement.
2. Rather, lock the thumb and hand in a very solid  position, with the knife 
at a long angle to the scion, and pull with the arm. Do not move the thumb 
toward the hand at all, keep this in a frozen locked position.  If the arm 
is not steady enough  - place it firmly against the body and let it slide.
3. Why the 'long angle to the scion'? When wood is cut at an angle  (rather 
than at 90 degrees to the edge) one gets a slicing cut which is a far more 
efficient and clean a cut. If one takes a protractor to a knife at 90 
degrees to the edge it will read - say 16 degrees - the  angle the knife was 
ground at.  However if you angle the protractor at a slant to the same edge 
it might read 10 degrees.
4. The second reason to draw the knife at an angle to the scion is that it 
presents twice the length of flat steel to the wood, and the idea of whip 
and tongue grafting is to get two very flat surfaces to join.
5. The edge. It cannot be stressed how important it is to have the bottom 
side of the blade absolutely flat.  However, even this is easily 
misunderstood. The back may seem very flat upon a cursory inspection, but 
the most critical part - right at the edge - is likely to be microscopically 
rounded or dubbed from normal wear - or improper sharpening. This defeats 
the point of having the back flat. If the flatness does not go absolutely to 
the edge - then the tool must be lifted off the plane of the cut - and thus 
the flat back can no longer guide the blade.
6. One way to tell if the blade is properly shaped and sharpened if to 
lightly touch it to a finger nail at a low angle - if the nail catches it, 
then the geometry is good.  (This is done so lightly there is no danger of 
cutting  the quick if the the blade slides on the nail, and so lightly no 
scar need be left on the nail). If the blade slides - rather that catches - 
keep raising the back of the blade until it catches. If it never does, you 
have a very dull blade. If it catches only when the back is angled up 25 
degrees or more, then the back is not flat clear to the edge.
7.Safety:  Always have a safety stop built into a cut before proceding with 
power. For instance, the knife hand in a w&t cut should be aimed so the back 
of the thumb hits the body instead of the knife. Test this by moving slowly 
and gradually increase speed and power as you develope confidence that it 
truly is safe, it most certaily can and must be.
8. When doing the tongue cut it is easy for the wood to give way and the 
knife to continue into the other hand - if a stop is not employed. To do 
this pinch the thumb of the knife hand between the thumb, scion and index 
finger of the other hand. Instead of cutting forward with knife hand rotate 
the knife and hand all locked together, pivoting on the trapped thumb. Set 
it up so that, if the knife keeps going,  the fingers will stop the travel 
before it goes too far. Also, by pivoting you achieve an efficient slicing 
cut.
9. All this can get laborious in words, the key is to have the attitude of 
working with as many grips as one can invent until there is a safety stop 
employed.
10.Sharpening:  A hardware store variety of carborundum stone can be used, 
however it is really only useful for coarse reshaping, even the 'fine' side 
is quite coarse. If you have a knife that is in good order, thy this to 
maintain it.
Acquire a flat surface, at least 2" by 6". I used a 6" x 12" square of high 
grade plywood. One could use thick glass, plexiglass, masonite, steel, 
whatever. Buy a can of all purpose spray adhesive , spray the back side of 
wet/dry sandpaper that is cut to fit the flat surface (don't spray the board 
or it may be difficult to remove and replace the sandpaper). On my 6x12 
plywood piece I glued down 4 grits 220 400 600 1200
With this homeade 'whetstone' you can now lap your knive's flat side truly 
flat. Be sure to have a good incandescent light nearby so you can examine 
very carefully the bottom side of the knife, there will be a microscopically 
thin reflection of light right at the edge, keep honing till it is gone. To 
hone the bottom side perfectly flat, push straight down on it with a finger 
while moving it around on the sandpaper. I see no reason to use water or oil 
on this sandpaper strop. 600 is the grit I use the most, 1200 is to give a 
slight microbevel to the top side, and as a final polish to the bottom side. 
I rarely use the 220, as I have diamond lapping stones which cut more 
efficiently.

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