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Setting the Chipbreaker

Here is a quick tutorial for setting the chipbreaker to reduce tearout.

The plane is a LN #4 1/2 with 50 degree frog (still too low for interlocked West Australia timber), chosen because it was close to hand. I can get the same results with a tuned English Stanley (which is not a highly regarded rendition of this plane) ...

1. Flatten the underside. Mark before hand ..

2. Hone on a fine diamond stone. I am resting the rear of the chipbreaker on the planing rest of a small benchtop bench I have. Note that this is very slightly undercutting the front ledge (that is, towards the rear).

This is the result …

I will point out that the LN chipbreaker has a small inner ledge. This does limit the amount of steel one can remove at the leading edge. Here is the LN (above) and LV (below) chipbreakers side-by-side:

For a review on chipbreakers, go here:

4. Hone the about 1mm (1/16”) of the leading edge of the chipmaker to 45 degrees. Here I am using the LV Honing Guide (because you should have one for times like this – while I freehand blades, the honing guide creates an even, consistent bevel at a reliable angle) ..

Not very accurate, is it …

EDIT (December 2022): I now recognise that 45 degrees is a little too low an angle to get the effect desired, and that 50 degrees is better. However, one should experiment up to 80 degrees. My current choice is closer to the latter.

5. Hone. I only used a fine diamond stone. However this one is broken in and probably about 3000 grit now …

Return to step #1 to remove the wire edge. It is tenacious so drag the edge through some end grain.

Chris Schwarz has offers useful tip about this area: treat the leading edge as if preparing a scraper blade, and turn the sharpened edge with a burnisher.

6. Set the chipbreaker. I’ve gone about 0.4mm. This took me 0.3 seconds to do now. When I started out, it took about 3 minutes.

7. Set the blade for appropriate depth, open the mouth a little (it is not going to make much of a difference, if any, to controlling tearout – but it will aid in allowing the shavings to exit the mouth), and start planing.

Here I grabbed a test board – Fiddleback She-oak, and I am planing into the grain just to show off.

Watch the shavings – they should be straighter than usual. Here they are straighter than curly, but not as straight as they can be. On the other hand, this is She-oak – very interlocked short grain – and I am planing into the grain ..

The results …

No tearout.

Regards from Perth


May 2015