Comments on: Reconsidering Chipbreakers as Not Totally Evil

By: HighRockWoodworking

HighRockWoodworking — Fri, 29 Jun 2012 01:42:18 +0000

Thanks Chris. Very interesting post. I love hand planes (metal and wood) and have built quite a few wooden planes myself, but the chip breaker has always been akward. I think it is time I play around with the settings a little more and try your method of honing. Wish me luck!

Chris Adkins

By: Bill Rittner

Bill Rittner — Tue, 26 Jun 2012 20:38:53 +0000

I learned the benefits of a tightly set cap iron some years ago while following a group of Galoots on the old tools mail list. These guys were expeimenting with cap iron and mouth settings in an effort to reduce tearout. During the discussion one guy mentioned that if he had his cap iron set extremely close to the cutting edge he could plane in any direction regardless of the mouth opening. This opened my eyes. I tried it and since then I have been using this info and rarely adjusting my mouth settings.

Now I need to experiment with the cap iron bevel.

By: dragoondr

dragoondr — Fri, 22 Jun 2012 15:37:40 +0000

I have just discovered that this works well on end grain so long as the cut is kept to a minimum.

By: Kees

Kees — Thu, 21 Jun 2012 08:46:32 +0000

Hi Tsade,

Sorry that it’s not so clear. I make a microbevel, just like on Chris’ picture above. Then I lay the capiron flat on the stone to remove the burr. There is no backbevel.

By: Gaijin Daiku

Gaijin Daiku — Tue, 19 Jun 2012 21:13:34 +0000

I was the lone American sub-flunky for two repair/renovation projects at the Japanese House here in Philadelphia (the curious can search http://www.shofuso.com) and got to spend over three months total with the carpenters from Japan. In 1999, the Hinoki bark roof was replaced and in 2007, some of the veranda (2 1/2″ thick Hinoki boards) and sliding doors were replaced.

In 1999, one of the roofers gave me a woodworking tool book–if I remember, the title translated to something like “Saw, Plane, Chisel.” ISBN 4844534815. A few fun facts from this book relevant to this discussion:

1. Two main bedding angles for Japanese plane blades are 45 degrees and 38 degrees 41′.

2. Most plane blades are sharpened at between 28 and 29 degrees. There was much more in the explanation, but it took me forever to get that much confirmed in translation.

3. Chip breakers get a secondary bevel of 70 degrees.

For what it’s worth, the lead carpenter in 2007 told me he puts an 80 degree bevel on his chip breakers.

My philosophy? If the throat is clogging, that’s the plane’s way of telling me to back off the blade.

Hope others find this useful,

Bruce

By: tsade

tsade — Tue, 19 Jun 2012 19:47:19 +0000

Excuse my ignorance and bad eyesight, but in Kees’ video, I can’t tell which side of the cap iron is getting the bevel. From the angle he’s holding the cap on the stone, I assume that he’s putting the back bevel on the underside (the side without the “curve’ for lack of a better term). Is that correct?

By: ewdysar

ewdysar — Tue, 19 Jun 2012 17:29:40 +0000

Hi Bones,

Chris has explored your position many times before. Read the first few paragraphs of this article again. Chris was obviously in your camp before these experiments and his earlier writings have eschewed the chip breaker. The point of this article was to discuss his surprising “discovery” of the advantages of a properly set up chip breaker. If you read this without preconceived ideas, you might learn something. Or not…

By: Kees

Kees — Fri, 15 Jun 2012 07:16:17 +0000

When you still have questions about how exactly you can turn your Groz plane into a Supersmoother, I’ve made a youtube video to show just that. It’s not a very elegant video, but it shows all the important steps.

http://www.youtube.com/watch?v=pSjpzta0FuY

By: zephyrblevins

zephyrblevins — Thu, 14 Jun 2012 22:01:05 +0000

In the film, with the higher angle chip breaker (80 degrees) at 1mm from the edge, the blade assembly looks a lot like the profile of a well burnished cabinet scraper. Hmm…

By: GregM

GregM — Thu, 14 Jun 2012 19:43:18 +0000

“Chipbreakers” or “cap irons” serve several purposes – not least in the Bailey-style adjuster design, they mate to the adjustment mechanism, and this required functionality can limit your range of options for positioning the breaker. But if you set it *really* *really* close to the cutting edge it effectively becomes part of the iron itself, at least from a geometry/wedge action point of view. So basically what you’ve got is equivalent to a back-bevel or high-angle frog. Not surprising really that this helps reduce tearout.