Wooden rabbet plane - bevel up or bevel down?

[Federico Mena Quintero]

I have a cheap wooden rabbet plane, straight, not skewed. Should I put the iron with the bevel up or down?

I've never seen another rabbet plane in person, so apologies for the noob question :)

[David Weaver]

If the bed angle is > 40 degrees or so, bevel down. If it's not, bevel up. It should be a bevel down plane - there's not enough rigidity in wood to have a 20 degree bed angle and a bevel up, though I guess anyone can make anything.

[Bill Houghton]

If you find a maker's mark on the plane iron (at the top), it should be facing you as you look down on the top of the plane. This is a fairly reliable test until you get a feeling for which way the iron should go. David Weaver's approach works, too: any angle from 40 degrees or so on up will be bevel down. I've got one wooden miter plane with roughly a 30 degree bedding angle, with the iron bevel up.

Consider the geometry, to understand what's going on. You can't sharpen a plane iron at much sharper an angle than 25 degrees without risking early edge failure; and the trailing side of the plane iron - what's "behind" the iron as you move the plane forward - needs some clearance. As you get down below 40 degrees, you reach a point at which the needed clearance disappears in a bevel down layout; indeed, at 24 degrees (with a 25 degree bevel on the iron), the "heel" of the bevel will hit the wood, preventing any cutting action. At the point at which the trailing-face clearance is compromised, it's time to flip the plane iron over, so the bevel is up, with the trailing clearance then accomplished by the bedding angle of the iron.

As many, many, many threads here and elsewhere point out, the cutting angle (angle at which the plane iron is presented to the wood) of a bevel-up plane is determined by the angle at which the bevel is ground combined with the bedding angle of the plane (for instance: 20 degree bedding angle plus 25 degree bevel angle equals 45 degrees); the cutting angle of a bevel-down plane is determined by and equal to the bedding angle of the plane. As a side note, I've taken to grinding my bevel-down plane irons at 30 degrees (Lee Valley uses this angle, and it makes sense: stronger for less chipping).

There is one exception here: Lee Valley sells a "flush plane" (http://www.leevalley.com/us/wood/page.aspx?p=32664&cat=1,41182) with no trailing clearance. I would argue this is not truly a plane, but a paring chisel with an oddly shaped handle; the action is more nearly chisel-like than plane-like.

Bill, who's avoiding the rain outside and really needs to get out there again and stop answering more question than you asked.

[David Keller NC]

I've seen (and owned) many wooden rabbet and dado planes, and I've never seen a professionally-made plane that was bevel up. Doesn't mean that they can't exist, but I would imagine that they are rare, at least if made in the British/American tradition.

[Federico Mena Quintero]

Thanks for all the details! I'll try this tonight.

[Trevor Walsh]

I believe due to the brittle nature of wood in such shallow sections any attempts at a BU woodie wouldn't have survived. the need led to metallic BU planes and ultimately to the demise of commercial wooden planemaking. Ironic huh?

[Zach Dillinger]

I've seen (and owned) many wooden rabbet and dado planes, and I've never seen a professionally-made plane that was bevel up. Doesn't mean that they can't exist, but I would imagine that they are rare, at least if made in the British/American tradition.

What David said. I've never seen a bevel up rabbet plane.

[Federico Mena Quintero]

WOW WOW WOW!!!

After setting the iron bevel-up, it works BEAUTIFULLY.

I know what happened - after buying the plane I sharpened it and put the iron back, but I didn't pay attention as to which way the bevel faced initially. The first time I mounted it bevel-down, and didn't like the look of the triangular "gap" between the bevel and the bed; I thought, "this gap doesn't make sense". So I've been mounting it bevel-up since then, and wasn't able to make it cut properly.

If it doesn't work, ask the Creek - they say, wisely. Thanks, everyone :)