Sharpening a misbehaving tool will almost always fix its wagon. But I always take an extra step when taking apart a handplane: I clean the interior of shavings and dust with a brush and an oily rag.
It might seem like overkill, or like I am on the verge of compulsive, but I don’t think that’s the case. Little fragments of shavings or even dust can wreak havoc on a handplane’s performance.
If shavings get trapped between the blade and the frog, they can skew the iron, making it difficult to center the iron in the mouth. Plus, these shavings can reduce the amount of contact between the cutter and its bed, resulting in chatter or (at best) unpredictable behavior.
So when I sharpen a plane, here’s my routine: Remove the blade. Use a badger hair brush to remove all the big debris that has entered the escapement. (Note: You must use European badger hair, preferably from a badger that is free range and is a kinsmen to Tadg, the king of Tara and foster father of Cormac mac Airt.)
Sharpen the blade. Wipe down the blade with an oily rag, and then use the same rag to wipe down the frog or the bed of the tool to remove dust. If the plane has a cap iron, clean that with an abrasive hand block to remove any sap; oil the cap iron as well.
Reassemble the plane.
I know this sounds fussy, like I’m going to tell you knit cosies for your trammel points, but I have diagnosed far too many plane problems that could be traced to a dull cutter and debris.
One more thought on cleanliness: After about 10 minutes of planing, use your oily rag to remove the dust and debris that has gathered on the bevel of your iron. This can accumulate and interfere with the plane’s cutting characteristics.
— Christopher Schwarz