Wednesday, 1 April 2009

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.

12 Comments:

Anonymous Narayan said...

Wow. That's a gorgeous log. I've never seen African blackwood which isn't already on a tool.

It'd be interesting to see how you mark out the larger log pieces for the infills and buns. I'm sure you try to get the most out of every log, which probably leads to some interesting three-dimensional layout.

2 April 2009 at 23:53  
Anonymous Anonymous said...

Konrad,

That first cut must be stressful on a piece of wood like that. It took me a couple days of thinking before I got up the nerve to cut up a small piece of Honduras Rosewood burl this week. Does it get easier with experience? Your saw has seen some terrific wood.

Thanks for sharing the process. We'll all continue to live vicariously through your blog.

Dan

3 April 2009 at 07:28  
Blogger Konrad said...

Hi Narayan,

It was a pretty cool little piece for sure... and heavy! I have been lucky to find a few really large pieces in log form - it brings its own challenges... but the advantages outweigh them for sure.

I have a series of templates for various planes that I often draw all over the various pieces. I buy white pencil crayons by the dozen:) I will often grab a previously roughed out part and simply trace that - having a 3D model really helps judge where exactly I can push the limits. As you can see from the photos - there are some areas of sapwood left on the pieces. These will be removed in the final plane - but by leaving them, I get a much better yield from the log. If I would have insited on solid black parts - I would have been lucky to get half these parts. That might make for an interesting post actually - watching the infills being reduced down to fit. Hmmm....

Cheers,
Konrad

4 April 2009 at 05:52  
Blogger Konrad said...

Hey Dan,

I have a photo that Joe took during the first cut in a serious piece of wood. I will try to find it and post it. It was a large Kingwood plank, and am on my hands and knees on top of it, using a D8 or something to rip it. We were scared out of our minds and did not want to waste the kerf. It was pretty funny in hindsight.

Cheers,
Konrad

4 April 2009 at 05:54  
Blogger stephen said...

Konrad, thanks again for letting me push all your planes last saturday, It was a truly memorable experience.

SRK

9 April 2009 at 17:44  
Blogger Konrad said...

Hi Stephen,

Glad you enjoyed trying the planes. It was a slowish show - but a very fun one.

Cheers,
Konrad

9 April 2009 at 19:30  
Blogger dan said...

I could spend days and days marking out how best to yield a log like that!

I am amazed you were able to get so many useful parts out of that piece.

Never really appreciated Blackwood until I had a chance to see it in a log form.

Really enjoying your Blog!

Dan Clermont

10 April 2009 at 03:24  
Blogger Konrad said...

Hey Dan,

Now where on earth would have have seen a Blackwood log before?

Cheers,
Konrad

10 April 2009 at 13:25  
Blogger dan said...

Same Place I saw heavily figured AAA Bird's Eye Maple, Burls, Brazilian Rosewood, Figured Brazilian Rosewood, Honduran Rosewood, Ebony, Ivory....... and on and on.

It was just off the Highway 401!

How long of a jointer could ya build with that Blackwood Log?

14 April 2009 at 02:40  
Blogger Konrad said...

Hey Dan,

The left over piece from this post... likely a 22-1/2" jointer. From the “other piece” maybe a 65" jointer:)

Cheers,
Konrad

14 April 2009 at 20:18  
Blogger dan said...

65" EH!!!

You would probably have to build a trailer for whomever purchased a 65" Blackwood Jointer AND they'd have the arms of POPEYE after flattening a board or two.

If they were smart they'd simply use winches to move the plane back and forth.

Seriously though, that wood sure is nice and I hope someday some of that 65" Blackwood gets used on my future jointer

Dan

Dan

14 April 2009 at 23:01  
Blogger Konrad said...

Hey Dan,

Yeah - I suspect I would need to put at least 3 totes on a 65" jointer!

And yes... there is certainly enough blackwood for your A2 jointer (I did warn you not to pick it up though)

insert evil laughter here

Cheers,
Konrad

16 April 2009 at 20:28  

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