Axe edge bevels?

[oetzi]

Everyone and his uncle is discussing the merits of different kinds of bevels for knives.
Now I would like to know what you think about the "right" one for an axe.
This being the tool too often taking second place when we "gear-heads" are together

 

[Klenchblaize]

Best argument for acquiring a double bit head like that on the "Marbles Hunter's Axe" (http://www.marblesoutdoors.com/cutlery/axes/hunterAxe.html) as you can leave one side as supplied and re-profile the other for finer work such as fleshing or woodcarving.

Cheers

 

[Tack]

Hi,
I've done a fair amount of reading about axes over the last few weeks. This forum and particularly the writings of Old Jimbo have been most useful. I seriously recommend that anyone with an interest in axes do a search for Old Jimbo's posts both on here and on other sites.
In addition I can heartilly recommend "The Ax Book" by D. Cook. This is a truly excellent read and I couldn't put it down from the moment I received it last week.
Tack

 

[British Red]

Oetzi,

Certainly agree with reading Jimbos collected wit and wisdom Old Jimbos Site - and indeed "An Axe to Grind" by Bernie Weisberger - available free in hardopy or as a download from the US forestry service.

My own illustrated musings (fairly humble) on bevel, shape and helve are in this post

Selecting an axe

Hope that helps a little

Red

 

[oetzi]

Thanks, I have read them all.
So, unlike with knives, there is a generall agreement that the edge ( I dont mean cross-sections of the bit) should be convex?
Thats ok by me, but I didnt expect it.

 

[British Red]

Oetzi, for our purposes I would say yes, clearly flat bevels come into play for shaping axes etc (Broad axes, side axes etc.), but giving our puroses of cutting and splitting, the secondary bevel is almost always convex. I gues the choice comes down to

"Hardwood or softwood"

and

"Cutting or splitting" as to how obtuse or acute you want the profile to be

Red

 

[OldJimbo]

So, unlike with knives, there is a general agreement that the edge ( I don't mean cross-sections of the bit) should be convex?

There's no big mystery with bevels, as they should line up with eye. So you put some tape over eye area and file or grind away.
Once you get close to filing to edge, you can switch to drywall sander and emery paper and slightly convex. That means that the whole bevel will be slightly convex, with the convex steepening at the edge to give it more robustness.
The simple advantage of having some convex is that once the edge bites into the wood, the chip is wedged out by the bevels without the edge actually touching much wood. That causes the axe to keep it's sharpness through a lot of chopping.
Some axes have very pronounced convex cutting bevels or very wide gently convexed bevels. This causes big chips to go flying out of the cut, and so keeps everything clear for further chops. You sure don't want to be stopping after every chop to pick out chips which have fallen back into the notch, and you can't count on always being able to chop in from the sides, so that chips fall out.

 

[Dave Budd]

For normal cutting type axes (i.e not side axes and spplitting axes) I normally do a compound convex edge. In otherwords I use a finer angle of grinding than I would want on the particular axe, then use a slighyly softer backing to the abrasive when putting the convex edge on it. This way I get better penetration and a stronger edge than either of the individual angles give respectively. I use wet n dry on a foam backing btw.

So far this has worked best for me.