My hand-planed rebate goes downhill - what's wrong with my technique?

Question

I'm hand-planing rebates in half-inch (12mm) birch plywood. The plane I'm using for this is an Axminster Rider No. 778 Duplex Rebate Plane. That's very similar to a Stanley No. 78 but the fence is secured on two rods instead of one.

Since I'm keeping the fence on the same side of the plane the whole time, I'm planing consistently in one direction (which happens to be with the grain of the top and bottom layers of ply). However, the rebate isn't "flat": the far end is deeper than the near end. In fact, there's a continuous downhill slope as you move away from the near end of the work piece.

Ultiumately perhaps I could help myself by setting the depth stop more cautiously - moving it by stages as the work progresses. That seems time-consuming though. Is there something I can change about my technique or body position to get more even material removal in the rebate (rabbet)?

Edit: I don't want to use an electric router since I work on this in the evening and don't want to wake my kids.

Answer 1

A rebate plane doesn't automatically cut to the same depth across the entire stroke. In theory perfect usage would come close, but most folks don't perfectly cut the whole thing with the same pressure every time, and few boards have equal hardness all the way across.

The solution is to not expect perfection. Draw a guide line on the end indicating where to stop cutting, and use that to tell you if some parts are cutting deeper than others. Use that to refine your technique—and if necessary (which it probably will be) to tell you where to make partial passes to level things out again.

There's no shame in making guide marks!

Answer 2

It sounds like the blade might not be engaging at the start of the cut. I would make sure that the blade is as sharp as possible and check that it engages at the front end of the rebate.

Best, Kevin