Krenov type plane with japanese blade..

[Chris M Pyle]

For those of you plane-building and japanese tool polymaths, do you foresee any problems with building a krenov style plane with japanese blades? I have found a few old japanese plane blades and a maker who will do custom sizes, just curious if there would be an advantage to this type of blade or if I'm just looking for headaches?

Also, if you wouldn't cross-culturalize the krenov plane, what blades do you all recommend? I've seen hock touted pretty heavily, is he the go to favorite of everyone?

thanks for any replies

[Zahid Naqvi]

Laminated planes (Krenov style) is just a technique used to make handplanes, you can change and modify the technique/dimensions/design to suit your needs. Adding Japanese blades should not constitute a problem, but it may require dimensional changes to accommodate for the thick blade.
On the other hand I suspect the Japanese blade will be expensive, and I am not sure it will add any remarkable improvement over the ones built by Hock for wooden planes.

[Michael Faurot]

. . .what blades do you all recommend? I've seen hock touted pretty heavily, is he the go to favorite of everyone?


I don't have a particular favorite vendor, but I do like to use blades that are plenty thick and avoid the added complication of a chip breaker. Lately I've been making them myself from O1 tool steel.

[Steve knight]

yes it is a problem. the Japanese blade is tapered thicker on the back then the cutting edge. this makes a wedge not work that well.
as far as I am concerned the Japanese got it right in how they secure the iron.
they have cheeck slots that are tapered and the iron is fit into them and the iron ed so it is a real part of the plane. its very solid and is really easy to adjust. but it takes some practice and skill fitting the iron.
years ago I had Japanese irons made so they were flat and straight so they could be used with a wedge or fit into an infill. the iron really improved the plane and made it easy to build. it is not too hard to build a plane body that will take a japanese iron. it will take some work to fit it to the body. but you will have a plane that will blow away standard krenov plane if done right. but you are limited to woods to use. a japanese iron needs woods that spring back when mashed. which oak works great. maple is ok. ash or hickory may work too. I have even made them out of ebony and other tropicals but they were a bear to adjust.
I may be the only one that has made glued up planes using japanese irons mounted in the traditional way. they have always been my favorite planes a joy to use. not sure how many I made 40 or so I think.

[Sam Takeuchi]

The part of the blade where it touches the bed has a slight curve along the blade and you'll have to shape the bed to make a good fit, but not exact fit (that'll prevent lateral movement). Also Japanese plane irons are tapered on the side and blade itself, you'll have to take these things into consideration when you are making a plane.

Wedge might be slightly tricker than normal tapered wedge. Top part of Japanese plane iron isn't precisely ground flat and then there's hollow of the blade. It might be simpler to use a mild steel and bend the corners or 'ears' by hammer to make a simple metal wedge than to try to make a good fitting wedge with wood.

Other than that, it should be pretty straight forward like any other laminated wooden planes.

As for benefit of using a Japanese plane iron is that...well, it's thick, so if the fit is good, it should be pretty chatter free. Also it's quite easy to sharpen since most of the 'meat' other than laminated edge is quite soft. Of course with a good edge steel, it should provide you with very good edge.

I have a spare Japanese plane iron here I've been thinking about making a Krenov style plane with. It came off of a $50 Japanese plane I toyed with years ago. I didn't like the plane itself, but it performed very well, and retained very good edge. The only thing I really don't like about Japanese plane iron is that periodically you'd have to do uradashi. It's a quite involving process of tapping the bevel of the blade with a hammer on the anvil (or other hard surface) to push the metal toward the back, and then flatten the back. When the hollow of the blade gets too close to the edge, that's the task to perform. I don't like doing it. If you try to just grind the hollow away, wedge will come lose real quick. That's the only reasons I'm still not doing anything with the blade. I don't like high maintenance tools in general.

So that's about it. Probably it'll make a good plane nonetheless.

[Wilbur Pan]

One of the often overlooked things about Japanese plane blades is that they are tapered along the length so that the top end of the blade is thicker than the cutting end, so if you look at the blade from the side it has a slight wedge shape. The side grooves of the body of the Japanese plane have a similar wedge shape, and that's what keeps the blade in place.

In western wooden planes, including the Krenov style plane, the blade is kept in place by a wooden wedge, not by side grooves, and often the blades were also wedge shaped, but in the opposite direction. The cutting end of the blade was the thicker end, and the top was the thinner end. The opposing wedge direction allows for a very tight fit and fine control over the position of the blade.

People have made Krenov-style planes with Japanese plane blades before, but it may be a bit more difficult to fit the blade to the wedge to give you that fine control over blade adjustment, since both the plane blade and the wooden wedge will be tapered in the same direction.

Finally, if you look at a Japanese plane blade, the sides are also slightly tapered, which you may have to account for in making the body of the plane.

Ron Hock's Krenov plane blades are really nice, and they run about $50. Although you can spend a lot more on a Japanese plane blade, you can find Japanese plane blades for about the same price.

Me, I really like using Japanese planes. My feeling overall is that if I have a Japanese plane blade, I'd make a Japanese plane body for it. If I want to make a Krenov plane, I'd pick a plane blade that is more suited for that style of plane. On the other hand, if you have a maker that will do custom work for you, and if he/she can make you a Japanese style laminated plane that is not tapered along the length or sides, that would be a really nice plane blade for a Krenov plane.

Edit: Sam types faster than I do. ;)

[Pam Niedermayer]

I pretty much agree with Wilbur, mainly because I think the forces on the abutments with a Japanese blade may be too strong for a laminated body. I'd get some live oak and mortise the blade cavity.

Pam

[Dale Osowski]

I would rather make a dai for Japanese blades than a Krenov style body. David Finck has some nice Krenov style blades, http://www.davidfinck.com/ not sure how they compare with Hock but I have heard good things.

[Chris M Pyle]

Thank you all for the thoughtful responses. This is a wonderful group

[David Gendron]

I love the Hock blade/ chip braker combination. they are fabulus irons!

[Steve knight]

now for something a little different.
http://i154.photobucket.com/albums/s266/knighttoolworks/planes/DSC00550.jpg

[Chris Friesen]

The replacement blades for the Taiwanese-Style planes at Lee Valley are high-speed steel and are supposed to hold an edge very well. They're 3mm (just under 1/8") thick. I've been thinking about using one of them to build a Krenov plane.

The price is certainly right...the largest blade is only about $13.

[Wilbur Pan]

I have found a few old japanese plane blades and a maker who will do custom sizes

I completely forgot to ask -- who's the maker that you found?