How to plane without making a bow

[Scott Stafford]

I believe Allen is right.

Long ago when I was infatuated with my plane's ability to take .001" shavings, I would often create this hump. With each whisper thin pass I would exacerbate the situation. More passes... more hump.

Adjusting my depth of cut to better accommodate the correction I was trying to make mostly alleviated the problem. Maybe .005" or .01" passes. After all, it takes a lot of .001" passes to remove an 1/8" of wood.

BTW, I most always just settle my stock up to a stop or bench dog.


Scott in Montana

PS I am still infatuated with .001" shavings... just saying.

[Kees Heiden]

There is also something like "being in control". I was also doing some roughing work with a jackplane today. To be honest, I wasn't quite in control! Shavings were too thick, the plane bucked sometimes. When you're not in control, chances that you are not getting a flat surface are high. Getting a concave surface is almost impossible. So you end up with a bow, a convex surface. It'll probably be out of wind, skewed and wedge shaped too.

[Mark Maleski]

Let us say you want a straight edge in something 15 to 20 inches long.

Taking stop shavings, till the plane stops cutting, is a good way to start. i e. deliberately hollow the length. Preferably with something like a 5, 5 1/2 or 6. Not a smoother.
A stop shaving starts and finishes just inside the ends, say 6 to 10mm.
......
This technique is demonstrated in my second Lie-Nielsen DVD.

best wishes,
David Charlesworth

I learned to do this via David's video when I was first learning and it still serves me well. I mostly avoid creating a hump these days but if I find I've added one I use this technique to get rid of it. Obviously you need to do this in the context of working to a line.

One other technique that I initially read from one of the {dreaded} bloggers, and that I think works well for beginners: visualize yourself trying to scoop out the center of the board with your plane. You won't be able to, but it's a good way to trick yourself into using the right mechanics. It's a little simpler than focusing on shifting downward pressure between hands as you progress through the slice.

[Christian Thompson]

There are several comments to weight the toe when starting and then the heel when ending which is important. If you do it the other way around the plane will climb up onto the start of board and fall off the end. I read somewhere to think of each stroke like you are trying to make a hollow. The flat sole of the plane won't let you, but the thought helps me transition the pressure correctly throughout the stroke. At least for me it's easier than thinking of pressuring the toe then the heal.

I also do what others are suggesting to work out the high spot in the middle and then work my way out to a final full length pass or two.

Edit - just reading through this thread again and noticed that I pretty much exactly duplicated Mark's post from directly above...

[Adam Cruea]

Huh. It's nice to see some of the old-time masters here have (or had) similar issues with that hump in the middle of planing.

Here I thought it was just me and I learned to start on the inside to create a small hollow, then plane the length of the board to level it out.

[david charlesworth]

This was exactly the technique, I was taught, 45 years ago.

David Charlesworth

[Warren Mickley]

I think a jointer plane that will not plane flat reliably and repeatedly is flawed. There are many times when we get the edge flat in length and then have to correct for wind, which could take several strokes. If those strokes are so bad that the edge is then humped, we would have to start over again.

If I had a jointer that would not repeat a flat surface, I think I would switch to a beech plane, jointer or trying plane, and alter the sole so that it would then plane flat. If the board's edge is humped to start with, planing just the high area in the middle is called for. However, I can't see constantly having to plane just the middle of the edge because of a faulty plane.

[Andrey Kharitonkin]

Somewhere I read that perfectly flat sole is not so good as slightly out of flat... If that is the case then I guess sole should have little hump to it.

[Daniel Rode]

I've read that a sufficiently skilled woodworker can make a flat surface reliably with a plane that has a slightly concave sole but a plane with a convex sole is a nightmare for all. The idea seems plausible but I can't prove it one way or another.

Somewhere I read that perfectly flat sole is not so good as slightly out of flat... If that is the case then I guess sole should have little hump to it.

[Kees Heiden]

This sounds like the wrong way around. With a concave planesole you certainly make a bowed edge. It also hampers the ability to take thin shavings. A slightly​ convex sole is less of a problem.

[Daniel Rode]

You are right. My response was backwards.

This sounds like the wrong way around. With a concave planesole you certainly make a bowed edge. It also hampers the ability to take thin shavings. A slightly​ convex sole is less of a problem.

[Robert Engel]

In trying to do a spring joint, I discovered it actually became nicely jointed after a couple full length passes. Wow.
For the life of me, I couldn't figure out what was going on till I realized maybe this is a better way to joint a board!

The Warren experience is, I believe, an illusion that begs the question what his definition of "flat" is.

[Daniel Rode]

The Warren experience is, I believe, an illusion that begs the question what his definition of "flat" is.

Re-read Warren's post. His two boards were fitted to one another without a gap. He then planed them and compared the edges. Unless he was able to plane a bow in one board and an exactly matching hollow in the other, it's a solid demonstration of flatness. I fail to see the illusion.