My intention was to not hijack Ken's thread on New Chisel Prep. This thread is to share thoughts on sharpening, sharpness and even testing sharpness.
Often the first sign of a blade needing attention is the quality of work a blade is performing. On a plane, the shavings can tell a lot. Here is a plane with a small nick in the blade:
Nicked Blade.jpg
The spot with the nick is not cutting creating a split in the shaving. Even though a thicker shaving may not split, it will leave a little line on the work that can be felt.
A thin shaving requires a sharp blade. Some of my blades do not seem to nick up like an A1/2 blade. They continue to take smooth shavings they just can not be dialed in to be super thin shavings.
The actual nick is difficult to photograph:
Hard to Photograph.jpg
You may be able to see where it is, follow the arrow. A dull spot or a nick will often show up under close examination under light. Even with poor eyesight a sparkly or a dark area can be seen.
After sharpening this blade it took a good full width shaving without splits:
Sharpened Plane Blade.jpg
The wood is a piece of alder from the firewood pile.
Testing on end grain is a helpful test for many folks. Here is an After & Before of a 1-1/4" Sandvik chisel:
Before & After.jpg
The patch to the right of the red line shows the surface made by a dull chisel with a few nicks. It is still sharp enough to pare a joint that will be hidden when assembled. To the left of the line is a patch cut with the same chisel after a trip to the oilstones. The shaving on the left patch was thin enough that it didn't remove remnants of the streaks from before the chisel was sharpened.
Here it is in action:
Clean Shaving.jpg
Smooth cutting of end grain may not be important to many woodworkers. If one is carving details such as letters or other 3D work, it can be the difference between looking sharp or looking rough.
Some folks do not like end grain to show. My taste differs:
Smooth End Grain.jpg
My DVD/CD/Blue Ray drive just didn't look right without a little elevation. This is also a piece of alder firewood, smoothed with an LN #62.
jtk