What Should I Do First?

The plane should be completely disassembled. Clean the adjuster and all machined surfaces with a rag dampened with solvent/degreaser, including under the toe piece if your plane has one. Old toothbrushes are also handy for this work. The rust preventative you’ve removed should be replaced with a silicone-free surface treatment such as Boeshield T-9 or Veritas Tool Wax. Use a light machine oil on the adjuster.

How Do I Sharpen the Blade?

First, polish the back of the blade. All that is required is to refine the area behind the edge, working your way up to the finest grit of your sharpening medium. The back has been lapped flat, so you are simply polishing this surface to the same degree that you will be honing the bevel.

The next step is to hone the bevel. The 25° bevel blade coupled with the 15° bed angle provides a 40° cutting angle. For harder material and difficult grain, you may want to add a 5° micro-bevel for better performance and edge retention as well as faster honing. Blade geometry is critical, however. It’s important that the cutting edge is maintained perfectly square to the sides of the blade. For that reason, a honing guide is recommended because it quickly provides accurate, repeatable results. Unlike many other planes, the blades of shoulder planes are never modified.

Once the blade is sharp, you can reassemble the plane. Opening the mouth and retracting the set screws will make the blade easier to insert.