Once I had the bagpipe reed fitted and kinda working, I marked out the expected hole positions according to Trevor Robinson's plan.
I cautiously formed the sound holes in the foot section to the correct diameter, and then the tuning holes at the end of the upper section (these are on the side of the body so can't be seen in this photo. I started at 4mm diameter, and cautiously opened them up, testing all the while for a C. In the end, I had to enlarge these holes well past the Robinson specification to get to C, and even then I had to push it a bit to be on pitch.
And so it went, up the scale. For each hole, I had to open the diameter beyond the plan, which suggests that the holes should have been placed further up. After a few holes, I started drilling them further north than the original plan. By this process, I made it from C to G without too much bother.
At this point, the holes are: four for the right hand fingers, and the lowest one of the three left hand holes.
Already, you can see a closed off hole beween the second and third holes.
Blocking off was easy enough: I stuffed a plastic bag up the bore to block the holes from the inside, and filled them with woodfiller. Once this hardened, I sanded the outside flush with the surface, and buffed the inside bore to a reasonable state.
Noting that the original holes were all on the flat side, I sited some new holes at convenient finger spacings and angles, not far down the body. However, I was finding it harder and harder to get a consistent tone from the reed, and the instrument as a whole seemed to want to jump up the octave, even for very low volumes.
It seemed to me that I had to revisit the whole reed and pirouette thing, and get a consistent operation.
All this would be after Canterbury Faire!
I decided to make a clean sweep of it and start the tuning again; I filled in all the finger holes.