correct axe bevel?

[knowslittle]

  Recently in my old garage I found a small broad axe left by the previous owner, but it's been sharpened haphazardly, and I'd like to correct that.

  Can anyone tell me if the sharpened edge of a broad axe should be sharpened flat like a chisel, or convex, given the back is still flat and true?  Looks like the original edge was definitely convex.

 Also, any reasonable way to tell, other than using it, if the temper has been drawn out of it from improper sharpening?

Thanks again for your knowedge and time, it is appeciated!

[Dave Shepard]

You first need to determine if the axe is a single or double bevel broad axe. One side will be flatter, and the eye will be off center on a single bevel. A single bevel will have a slight curve on the flat side, it is not perfectly flat like a bench chisel. I have some pictures in my gallery that may be helpful, I'll search for them in a minute. Try filing the edge, the file should just skim over the steel. If you can file it easily, it is not very hard.

edit: I couldn't find the pics I was looking for. I might have them on the PC somewhere. If I find them, I'll get them uploaded.

[moonhill]

I would like to add that if the file does not bite it may be to hard, therefore brittle.  You may find it has hard spots and soft spots.  I would look for a uniform toughness.  I like to file my axe.  I have a variety some soft some harder.  As I said, look for uniformity in the steal. 

Tim

[Jasperfield]

Dave,

Please discuss more about the single vs. double bevel broad axe. Are you talking about a single "bit/blade" axe or a double bit/blade axe. Or are you talking about an axe having two bevels ground on the same bit (i.e. like a microbevel on a chiscel)?

Also, please talk about the off-centered eye.

Thanks, Jasperfield.

[Dave Shepard]

I'm talking about hewing (broad) axes, which have only one cutting edge. The cutting edge is offset to keep your fingers away from the log as you are hewing it. Some broad axes are not off center, and have a noticeable bevel on both sides of the cutting edge. I will have to take some more photos of my axes later. Here is a coopers broadaxe showing a very offset eye.



I don't have my sharpened axe here, so I'll have to take a picture of another one that I have to show the cutting edge. This next photo is of a larger, ~9", head so you can see what we are talking about. I will get into the double versus single bevel when I get some more photos. It is not like the micro bevel on a chisel.

[Jim_Rogers]

I don't know if this will be helpful or not but a while ago, we had a broad axe head that had a chip out of the cutting edge, so I took some picture of it for asking questions about what to do about it.

Here is a shot of the none flat side:



Here is a picture of the flat side showing that it isn't truly flat it has a slight curve to it:



I have one more picture of it but it only shows the area where the chip was, and isn't really important to this discussion.

We did end up selling it as is to a timber framer who felt he could deal with it.

Broad axes should have one flat side and one side with a bevel.....

[Jasperfield]

Thanks.

I see what you mean re the offset. I have a right and a left. That offset is a handy thing. It makes it useable.

[knowslittle]

Dave- Yes, the axe head has a bevel on one side only, and "flat" on the other side (similar to Jim Roger's pic), but the side with the bevel actually appears to be convex in shape, maybe some 5/8" wide,  with  something like a micro-bevel at the edge, apparently from subsequent sharpenings.
  What I don't know is should I keep the convex bevel, or sharpen it like a plane or chisel blade?
Is there an reason it would originally come with a convex (rounded) bevel?

Thanks!
Bob

[moonhill]

Bob, are you wondering if the cutting edge should be straight, as in, if you placed the cutting edge against a table as Dave's picture with the handle, would the cutting edge make contact all along the edge or would it be able to rock backing forth?  It should rock back and forth.  The curve in the blade will allow the leading edge to plow through the wood as a boat does, it takes a chip away gradually, a leading edge, if you will.  You will see in Jim's photo that the non beveled side is not flat either in the photo with the square applied to it.  In other words there should be no flat surfaces.

As for the angle of the bevel I don't like a blunt angle, the amount you are polishing , the exposed bevel should be close to a 1/2" depending how thick the blade is. 

Tim

 

[routestep]

As Dave Shepard has shown in his second picture and Jim Rogers in his first picture, the hewing axe cutting edge should have a sweep or curve to it.

A cross sectional look at the blade bevel should be flat, maybe some people put a hollow ground edge on it, but I aim for a flat bevel as I sharpen by hand, slow but no heat generated.

The non bevel side of the blade should be concave as Jim has shown in his second picture with the framing square against the axe blade.

All this said, when the axe comes down on the wood, one small point on the axe blade touches the wood first, a nice slice takes place as the axe needs to be very sharp. I would guess half of the blade doesn't touch the wood at all on any given slice.

Hope I didn't muddy the waters, person to person is much easier. An axe blade is a little tricky.

[eamassey]

Very interesting.  Now I will have to check my father-in-law's broad axe.  I can say that I was more than forty years old before I realized that a broad axe was a woodworking tool.  In my childhood, I never saw a broad axe used but for one function,  and that was to shave the side walls, while hand digging a grave.   (pre-backhoe era.)  In my older age I am ever more interested in the old tools and methods.  But these are not the tools of my father, but my grandfathers and great-grandfathers.

[knowslittle]

thanks to all for the input.  All very usefull.
Bob