An introduction to roughing infill parts

Finding appropriate wood for infilling planes is the single biggest challenge to a planemaker. Sure the price of metal is constantly moving... but they aren’t making high quality wood anymore! At least not the stuff that I need to use.

A few years ago, I picked up this rather odd-shaped piece of African Blackwood. I knew right away it was old - from the tool marks used to cut it (an axe not a chainsaw), the color (purple black, not brown black) and how it sounded when I tapped it with a metal object (a hollow ring as opposed to a dead thud). I have been storing it for a few years now, and the need for a few more A5 and XSNo.4 sets prompted me to cut into it.



The first step is to create a few flat reference surfaces - a real challenge with such a heavy and awkward piece of wood (African blackwood has a similar weight to volume ratio as mild steel). I use a sled with my bandsaw and slowly start to establish a flat surface.



This small log had quite a bend it in - so rather than square it up and waste all that material - it made more sense to cut it at the bend. This would also give me a chance to see what was going on inside - there were several dips and pockets on the outside and I needed to know if they affected the interior. The photo above show the chalkline to mark the crosscut.

Time for a deep breath...


Phew... not too bad.



And a close up to the grain. This is pretty typical. Some of the exterior voids and pockets go absolutely no where... some lead to disasters.



I always start milling the worst piece and work my way to the best piece. Here is the short end squared up a bit more - a pretty ugly looking thing at this stage.

Another deep breath... time to split it.



And a bit of a disaster. Some pretty serious inclusions to work around. Thankfully I cut everything oversized so I should be able to get a few parts from these two pieces.



On a positive note... the moisture meter confirms what I suspected... this is very old, dry stock.



Several hours later - I was done milling the short end. Three XSNo.4 rear infills, two XSNo.4 front buns (I had a spare from the last time I milled, so I have 3 complete sets), and 5 front buns for either A5’s or A6’s.

I apply a quick coat of shellac on the endgrain, date each piece, and put them on the shelf until they are needed.