contents: woodworking: simple sharpening jig
saw braces
home | Fairlead | sailing glossary | buy a kit here |
Sharpening chisels and planes If you plan on doing some woodworking, making replacement centerboards, or modifying the
hull of your model sailboat, you need sharp tools.
There are two edges to a plane or chisel that need surfaced.
The first surface is the grinding angle, at 25 deg. this angle lets you hone the other,
sharp whetting angle at 30 deg. without having to spend all day at it.
The grinding angle is best done with a wheel, and the whetting by hand.
The problem with hand sharpening is that the hand and arm movement never results in a perfectly
flat keen edge. The result is a honed edge that is rarely flat but slightly rounded, due to
slight variations of the angle a hand and arm movement will make with each pass over the stone.
Even though it feels sharp, hand sharpening results in a slightly rounded
honing edge that makes the iron skate over the wood fibres instead of digging in. After years
of practice I got pretty good at it, still, all it takes is a couple of strokes, smiling' away,
while looking' out the window.....and you just wasted all your time.
There are sharpening jigs available you can buy that hold the blade at a steady angle, and
they are less expensive than what they used to be, but here is a simple sharpening jig you can
make for free, and its actually quicker to use than the kind you buy.
I came up with this simple gadget a few years ago. All you need is a piece of 1" x 2" scrap
wood about a foot long. On one side you mark a 30 deg line and then saw into that line, about
1/8th. of an inch deep. Hand saws will not produce a slot wide enough for holding blades so, you
will have to make it a little wider, use the edge of a thin file, or a metal ruler with some
sandpaper (whatever).
The edge of the chisel, or plane blade sets into the cut and holds the blade steady as
you stroke over the stone.(concentrate on the forward stroke and you avoid creating a burr)
The last stroke removes the burr, the blade is laid down and firmly held flat on the stone,
(honed side up) and dragged along the length of the stone, just once. Hold the blade near a
light source and angle it about as you look at the edge, if you can see a very thin line
shining off the edge, the blade is still dull, get back to work until it disappears.
The one in the drawing doubles as a push stick for table saw use. Note: the 30 degree angle works well with softwoods like pine and cedar,
some woodworkers who use hardwoods such as oak, prefer to use a 25 degree angle for honing,
and so the grinding angle will be even more acute - 20 degree.
____________________________________________
Saw braces
These little known devices are great for anyone with a workshop.
The idea is simple, a flat board with a fence on each end, one on top and one on the bottom.
Usually made in pairs, the bottom edge of the brace butts against the edge of a table or
workbench, the board you are going to cut rests against the other. You push against the board
with one hand and saw with the other hand. The braces hold the board steady as you saw away.
You will find yourself using them all the time, and for more than just sawing boards,
they can also be used when sanding, carving, scraping, or any work where a 'third hand' is needed to hold a project steady.
I use one with a notch in one of the fences to hold a model hull in place when planing a hull.
(The notch will also support 1 in. thick stock on its edge. (handy for working small pieces)
You can design them to suit your own needs, cut an angle through each end and use it for mitre cuts.
I have several in a variety of widths and lengths, an easy project you can make with scraps of plywood and
1 x 2 lumber.
___________________________________________
Visit our photo gallery yet?
with a simple, home made honing jig.
You can set the jig right down onto the stone, the oil will keep the stone from clogging.
The oil will absorb into the wood, and over time give it a nice finish.
When the width of the whetting angle gets to be about 1/8 " on a chisel, or more than 1/16" on a
plane, its time to grind.
You can also saw a grinding angle (25 deg.) on the other side of the jig. If you have a lot of
time on your hands, (or no grinding wheel) and a two sided stone with a course and fine surface.
The course side for grinding, the fine for honing.
