My answers and more questions
GolfSteve in Calgary
>1. I hollow grind often. This makes freehand sharpening much easier because there is less metal to remove by hand and "feeling" the angles is easier. One trick I learned here is to put a convex shape (rounded upwards) onto your grinding wheel surface. With this shape only the centre of the stone does the grinding, and there is much less worry about catching an edge near the sides of the stone. You also don't have to worry as much about keeping the plane blade square to the wheel. This is analagous to using a single point fence on a bandsaw to cut a straight line.
I touch the blade centre to the wheel, then move the blade to one side. I then pull the blade back, recentre it, touch the blade to the wheel again, and slide the blade to the other side. This keeps me from spending too much time near the blade corners.
I get pretty good results freehand, but I do get better results by using the Veritas grinding jig to keep my blade square to the stone. I grind until there is only about 1/32 to 1/64 of an inch of unground steel near the cutting edge. Grinding all the way to the edge guarantees some buring of the steel. Unless I have a brain fart or sneeze at a critical moment I never burn the edges. Hollow grinding an iron takes me about five minutes. I stop frequently to inspect my progress and allow the iron to cool.
2. I freehand both chisels and plane blades. I actually find chisels easier to freehand, except for blades less than 1/4" where I have some trouble keeping the edge square.
3/4/5. Because I hollow grind, the primary bevel only touches the stone at the toe and heel of the bevel. This allows me to quickly reference the primary bevel angle on the stone (ie. "click" the blade onto the stone). I then raise the blade a couple of degrees and form a secondary bevel on a 1000 grit stone. I stop when a good burr is formed.
I then switch to the 8000 stone, find the primary bevel angle, raise the blade up a few degrees to find the secondary bevel, then raise the blade a tiny bit and hone a mirror bright tertiary bevel that is only about 0.5 mm wide (or until the burr is completely removed).
The last step is to flip the blade over and hone/flatten the backside. I've been experimenting with the ruler trick, but I'm wondering if this is somehow contributing some of my sharpening inconsistencies (see below).
I stridently try to avoid a convex bevel (a bevel bulging outwards). A convex bevel makes trying to find and maintain bevel angles difficult. With a convex bevel you're never sure if you're shapening the very edge of the blade (which you want to do), or if you're just polishing up some portion of the convex bevel.
Once my secondary bevel gets a bit wide, it becomes difficult to easily "feel" the bevel angle on the stone (click the blade in place), and it is time to hollow grind again. The secondary bevel only gets about 3-4 mm wide before I regrind.
With the two microbevels, I think I've run into some clearance angle issues in the past. I used to hollow grind at 30 degrees; but by the time I formed the other two bevels, I might have been up as high as 37-40 degreees. I now hollow grind at 25 degrees, and the final bevel ends up around 35 degrees. I'm still experimenting with this.
6. Nope, backwards and forwards. I can't get the hang of side to side motion while keeping a constant sharpening angle.
7. Nope, I think it would be very difficult to keep a consistent angle if you are picking up the iron on the forward stroke.
8. The Vulcan death grip. I find that I try to apply too much pressure; especially when I'm getting frustrated with my efforts. I try to keep a relaxed grip and light pressure on the stone. My left hand cradles the underside of the blade. My right hand has three fingers applying pressure to the top of the blade near the edge. The thumb and pinky of the right hand wrap around the blade, locking with my left hand.
Pressure is critical to maintaining a square edge. Too much pressure on one side and your blade edge will end up skewed. Alternately you can manipulate pressure to develop a crowned blade edge.
The height of your sharpening bench is also important. About waist high works for me. The lower than normal height makes it easier to lock your elbows and wrists to maintain a constant bevel angle.
9. Similar grip for chisels, but less fingers apply pressure.
Now for my question - I freehand sharpen, but have been having some difficulty lately even though I'm sharpening more than even due to working on a maple workbench. Maple is a difficult test of my sharpening skills. My problems are somehow related to the edge folding, or a remanent burr remaining. After a few strokes on the plane there is a noticeable burr on the backside of the iron (which was not there when I finished sharpening), the blade is dull and I have to start over. ##%$*#^!!!! Sometimes I end up with an edge that will last 30 minutes, other times I end up with an edge that is dull after five strokes. Any ideas???