: I've found planing with a block plane (as described in N. Shades kayak
: book) to be a bit troublesome. I've noticed that ....... the mix of hard and
: softwoods to make it difficult to judge the pressure.

I have a narrow (1/4") strip of black walnut running through my deck, with cedar on either side. I also had trouble with the block plane around the walnut, although I had reasonable success with the plane taking the ridges off in areas where there was no hardwood. Even so, there was still the odd spot where I got some minor tearout, cuz the grain in adjacent strips ran in opposite directions.

After knocking the ridges off, I used a ROS for most of my rough fairing, followed by a fairing board for fine fairing and finish sanding. But the walnut strip still stuck up higher than the cedar on either side of it. You couldn't see it except in the best light, but you could feel it with fingertips. A freshly sharpened scraper took care of that. I used a cabinet scraper instead of the "handle-type" scraper that Ted refers to, but only because that is what I am used to using. (BTW - if you do this when you're near the finish-sanding stage, be sure to go over the scraped areas again with a light sanding, before applying epoxy. Otherwise you could end up with an uneven finish.)

Even after scraping, the walnut was still slightly higher than the surrounding cedar, but I didn't know it until later. This time, you couldn't see it or feel it. I only discovered it after the glass and a couple fill coats were applied, because there was a distortion in the way light reflected off the deck along the walnut strips. The distortion disappeared entirely in the final epoxy sanding.