An experiment!

I mentioned last time that I use hand planes and I avoid sand paper. The main reason for this is that the plane produces a superior surface. A secondary reason is that wood dust is dangerous stuff to breath.

Sand paper works by scratching the surface of the wood with an abrasive. Proper use dictates that you progress through a series of finer grits. Each grit replaces the scratches from the previous grit with finer scratches. You continue until you reach a scratch pattern that is hidden to your eye.

A hand plane is essentially a holder for a blade. The blade finishes the wood by shaving a thin slice of wood from the surface. I am capable of adjusting my planes to remove a shaving that is 0.0005 inches thick. That is significantly thinner than a human hair.  

I did a little experiment for you. I took a scrap of wood from a discarded crate, selected a nice chunk about eight inches long. One side I sanded using the progression of grits 80, 110, 220. Most woodworkers agree that 220 grit is a good place to stop before applying finish. I sanded carefully to get the best surface I could, this is an experiment and we want to measure results not prove what we hoped for. The process took about 5 minutes.

The other side I planed with a fore plane and then with a smoother. We'll discuss another day the difference between the planes. The planing took less than 2 minutes.

This is the sanded side of the board under my digital microscope. You can see the scratches moving from the lower left to the upper right. The wood is flat enough to reflect the light from the microscope. If I were to apply a clear, film finish you would be pleased with the appearance.

This is the planed side of the board at the same magnification. You can see that there are no scratches. The surface of the board is so smooth that it reflects light in a way that reveals the texture of the wood even at this high magnification. When a clear finish is applied it will "glow."

Hand planes allow me to do other things that are difficult or impossible with machine tools. An easy example is fitting a door on a cabinet. With the plane a can remove whisper thin shavings until I achieve a perfect fit. Attempting the same on a powered saw would be frightfully dangerous and wouldn't be even close in the level of precision.

W. C. "Bill" Sias, Joiner and Cabinetmaker.