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Building a Krenov Smoother



Here is a pictorial of building a Krenov-style smoother.

Krenov advocated building planes by laminating sections together – the sides, and the two central body parts. This is a relatively easy method of plane construction, one that relies primarily on the use of machines, and can be turned out quite quickly.

Building a laminated plate does not automatically make it "a Krenov". What makes it a Krenov for me is the cross pin. In addition, these planes have a low centre of gravity. The cross pin is shaped to turn so as to find the best angle to hold the blade (some builders of laminated planes simply use a round dowel. This does not have the same holding power. The low centre of gravity comes from the plane's height (e.g. the cross pin is 1 1/4" from the sole). It is this low centre of gravity that gives these planes such terrific feedback. Krenov shaped his planes for comfort and feedback. His followers made them look nice because we give the tool more importance than he did.  

Below is a plane in my collection that was shaped by Jim Krenov. It was bandsawed to shape … looks rough as guts … but it is extremely comfortable in the hand. And it works as well as one might expect coming from James Krenov.





Below is a series of photos to guide you through the building of a Krenov-styled plane.

This one was constructed from West Australian She-oak. It will be a small smoother, just 7” in length, with a 55 degree bed to work the local interlocked woods. The blade-and-chip breaker is a 1 ½” wide Hock, the same as used in the Krenov Smoother, and typical of those used by Krenov and the students at the College of the Redwoods, where he taught.


Step 1: Begin with a dimensioned block of wood. Saw this into three sections …

The sides are intended to finish at 5/16”, so allow for this. The centre section is 1 ½” + 1/16” for a little lateral movement.




Step 2: Sides are cleaned up with a handplane.


Here they are together. Note that I am building two planes, the second in Jarrah.


Step 3: Mark the bed and throat.

I have placed the bed 2/3 from the heel of the body. Both the bed and the throat are 55 degrees. You could raise the throat to 65 degrees if you lower the bed to 45 degrees.


Step 4: Cut the bed and throat sections.

I did this on a table saw. No fuss, and minimal cleanup.


Pushing all the pieces together, it looks like this …


Step 5: Shape the wedge bar.

There are many ways of doing this. I chose to use a lathe to first turn a 3/4” diameter cylinder. The tenons are each ¼” in diameter.



The cylinder now needs to be shaped …

  1. 2. 3. 4. 5. 6.


Key (in order): Plane a flat on one side (I used the shooting board). One flat side will enable you to plane second, and third, flats on the shooting board. Now shape one side into a half-round with a rasp or file.


Step 6: Route out the groove for the chip breaker screw.

If you are using a blade with a chip breaker, it will have a screw. A groove must be created in the bed for this. The groove only needs to be wide enough for the screw.

No photo – I forgot to take one. However, here is a bad picture …



Step 7: position the holes for the wedge bar tenons ..

To make this task easier, I glue up one side piece to a rear centre section (heel) to prevent any accidental movement. Note that the toe section is still loose.

The wedge is hardwood, the same width as the blade, and with a 10 degree angle. Shaping will be completed later. Leave it over long for now.

The lower section of the wedge will end about half way between the end of the blade and the centre of the wedge holder’s tenon. The latter is 1 ¼” on this plane.



Position the wedge holder and mark the position of the tenon.


You can now drill the hole for this tenon.

To fit the tenon on the other side, simple align the sides together and drill through the hole of the one into the body of the other.


Step 8: Glue the sections together.

With one fixed side, it is also now easier to align the second side. Simply slide it back and forth until the wedge is held with equal pressure at each end.

Adjust the front section (toe) so that the mouth is about 1-2 mm too small. The plan is to plane down the sole, and this will provide some leeway for a tight mouth at the end.



The glued up body …


Step 8: bandsaw the body to shape …



Step 9: rasp and files to smooth and complete the shaping …


The final plane

Alongside the smoother is a small block plane. This had a body length of 5 ¼”, and uses a 1 ¼” wide and 1/8” thick Mugingfang blade (available from Lee Valley). The construction is the same as the smoother, however the bed angle of the block plane is 40 degrees. This provides for a low cutting angle that works end grain well.



The mouth is very tight.


Overall, both these planes offer superb performance, out of the top drawer. They are extremely comfortable in the hand, both may be used either one- or two-handed, and offer wonderful feedback. World class performance for the cost of your time.


Regards from Perth

Derek


April 2013