I have read many articles on tuning up hand planes. They all say use a precision straight edge. I may have missed it but I can’t seem to find what is meant by “precision” in a straight edge for testing the flatnes of the plane bottom. For example is my Starrett combination square accurate enough?
Along the same line – if you are checking the sole of an 18 or 22 inch plane can you use a 12 inch straight edge?
Thank you.
Bob
Replies
Bob,
Precision comes in various degrees, but in this context, you are looking for something more reliably accurate than is usually found in woodworker's tools. Fortunately the most basic, and not terribly expensive, machinist's tools can offer the accuracy you need.
For most work, the 12" blade from a Starrett combination square is reasonably accurate if it hasn't been beaten up. Beyond that you can find machinist's straight edges in various lengths, but they get heavy and expensive as they get beyond 2 feet long.
Using a short blade to judge the flatness of a slightly larger surface can give you a sense of how flat the surface is, and whether you need to continue with the flattening, so using a 12 inch straightedge on an 18" plane sole will work, but you may have trouble correctly judging the flatness of the 22" plane with a 12" straightedge.
John W.
Thank you for your response.
Bob
This forum post is now archived. Commenting has been disabled