Originally Posted by
Tom Bussey
You are correct about a myth about a perfectly flat sole. Any plane will cut very well with a sharp blade, that is the real secret.
Some planes will not work well, even with a sharp blade
https://sawmillcreek.org/showthread....ole-hand-plane
This plane's sole was convex from toe to heel with the high point being at the mouth.
Anuj was invited to bring this plane to my shop to see if my block of granite with abrasive paper might make things better.
He is now a happy owner of a plane that works well:
https://sawmillcreek.org/showthread....ley-3-is-fixed
You are correct in that the sole does not need to be perfectly flat. Anuj's plane's sole is flat enough to make a fine shaving with no pressure applied to the plane, only using forward motion. It will also make the same shaving with pressure on the tote and knob.
A concave sole will often require the blade to be advanced until it starts to take a shaving. Then the blade will dig into the wood and make a thick shaving or possibly let go only to repeat itself. This was the case with one of my Stanley #60 type block planes purchased at a yard sale for $1:
https://sawmillcreek.org/showthread.php?123401
This one also had a problem similar to the azimuth problem mentioned by Tom Trees. The bed was a bit higher on one side than the other causing slight a horizontal tilt to the blade. It would start cutting on one side before the other no matter how much lateral adjustment was given to the blade.
If a plane of mine is able to make a shaving of a thickness normally required for its intended use, then it is left as is. It is likely easier to mess up a plane's sole attempting to lap it than it is to make it better. A person needs to know what they are doing and where they want to go when trying to fix an errant plane sole.
Many things in need of doing and doing well, are not simple procedures to be performed without exerting some brain power.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)