07-24-2013, 06:27 AM
I just finished a class on Japanese woodworking. One of the things that was covered in this class was the use of chipbreakers in a Japanese plane. Even though there are a lot of obvious differences between the chipbreakers in a Japanese plane and western/Stanley planes, at the level of what is physically happening to the wood, they seem to have many things in common that allow them to perform their function.
They need to be set very close to the edge. The teacher, Yann Giguerre (who was a fantastic teacher), mentioned that he routinely sets the chipbreaker closer than 1/64", and probably winds up closer to 1/128" in most cases.
The chipbreaker is not razor sharp at the tip. A small microbevel is put on the chipbreaker with a high grit waterstone at about 80º. This seems to be similar to Nicholson's rounded bevel that Warren referred to.
I've never been able to use a chipbreaker effectively in a Japanese plane before. After this class, I was able to plane a smooth surface on a piece of bubinga with interlocked grain, and the bed angle of my Japanese plane is about 40º.
Having said that, there are other ways of managing tearout, all with advantages and disadvantages. Tight mouths help. Higher bed angles help. Sharper blades and thinner shavings definitely work. More info here.
I think that the reason that using a chipbreaker was not more common in the recent past was because some of the information needed to be able to use a chipbreaker effectively was not in a form that could easily be understood at a distance by most people, as opposed to seeing it in person. I know that personally, I never really understood how close the chipbreaker needed to be to do its job, and I don't think I'm a complete moron.
I had read that you needed to place it as close as possible to the edge, which I did to the best of my ability at the time. Looking back, I know now that my chipbreakers were too far back to work.
It's true that the information was out there. As Warren pointed out, Nicholson did say that the distance from the cap iron to the edge of the plane iron "depends altogether on the nature of the stuff". But for today's audience, adding in a little more information like, "You'll most likely need to be within 1/128" to 1/64" for smoothing," and "If you still get tearout, move the chipbreaker closer, and if the shaving comes out like an accordion, you can move it back," goes a long way towards making the information a lot easier to understand, especially if you are not seeing this in person.
They need to be set very close to the edge. The teacher, Yann Giguerre (who was a fantastic teacher), mentioned that he routinely sets the chipbreaker closer than 1/64", and probably winds up closer to 1/128" in most cases.
The chipbreaker is not razor sharp at the tip. A small microbevel is put on the chipbreaker with a high grit waterstone at about 80º. This seems to be similar to Nicholson's rounded bevel that Warren referred to.
I've never been able to use a chipbreaker effectively in a Japanese plane before. After this class, I was able to plane a smooth surface on a piece of bubinga with interlocked grain, and the bed angle of my Japanese plane is about 40º.
Having said that, there are other ways of managing tearout, all with advantages and disadvantages. Tight mouths help. Higher bed angles help. Sharper blades and thinner shavings definitely work. More info here.
I think that the reason that using a chipbreaker was not more common in the recent past was because some of the information needed to be able to use a chipbreaker effectively was not in a form that could easily be understood at a distance by most people, as opposed to seeing it in person. I know that personally, I never really understood how close the chipbreaker needed to be to do its job, and I don't think I'm a complete moron.
I had read that you needed to place it as close as possible to the edge, which I did to the best of my ability at the time. Looking back, I know now that my chipbreakers were too far back to work.It's true that the information was out there. As Warren pointed out, Nicholson did say that the distance from the cap iron to the edge of the plane iron "depends altogether on the nature of the stuff". But for today's audience, adding in a little more information like, "You'll most likely need to be within 1/128" to 1/64" for smoothing," and "If you still get tearout, move the chipbreaker closer, and if the shaving comes out like an accordion, you can move it back," goes a long way towards making the information a lot easier to understand, especially if you are not seeing this in person.
Hail St. Roy, Full of Grace, The Schwarz is with thee.
Blessed art thou among woodworkers, and blessed is the fruit of thy saw, dovetails.
Holy St. Roy, Master of Chisels, pray for us sharpeners now, and at the hour of planing.
Amen.
$300 is a lot of Money!
giant Cypress: Japanese tool blog
Blessed art thou among woodworkers, and blessed is the fruit of thy saw, dovetails.
Holy St. Roy, Master of Chisels, pray for us sharpeners now, and at the hour of planing.
Amen.
$300 is a lot of Money!
giant Cypress: Japanese tool blog
