The F Tool™
The F tool™ can find and correct air leaks caused by a reed plate that is not perfectly flat.
Use it on Both the blow plate and the draw plate.
Read the older, more detailed instructions here:
How to use the F Tool
These instructions use the French Tuner to measure flatness instead of the reference bar. The newest version of the F-Tool includes its own reference bar. Use it in the same way.
This tool includes shim stock.