Bit/Blade Profile Question

[1215]

This was an eBay purchase and I knew going into it that it had a really bad and inconsistent edge from a grinding wheel. It actually turned out to be a good thing that it was so dull because it was easier to work with for my first hang. Now that I'm sharpening it I'm finding it extremely hard to file (hard steel). Stones are working very well (coarse traditional stones with oil as well as diamond stones) however it has been a very time consuming process to have gotten the bit just to this point. Because files were not working well at all, I started with the coarsest traditional stone I have to get rid of the big burrs and high spots. Next I moved to a black and then blue DMT stone and finally I've been using a Spyderco Triangle Sharpmaker, starting with their CBN reprofiling rods then moving to the standard grey and white ceramic rods.

There are a few places where the profiles meet properly --and the blade is very sharp. In those spots it is now sharp enough to shave hair from your arm. However, where both sides of the bit profiles do not meet properly (one side still has the grinding wheel profile), it is not dangerous-dull but it is not properly sharp.

Realizing that fixing the profile means removing metal, should I just use the hatchet as-is, knowing that I'll eventually get to a profile I like through repeated use and sharpening? I've not finished hanging it yet but I think even the dull spots are probably safe/sharp enough to split kindling/small wood with. My biggest concern is the uneven bit profile from grinding by the prior owner. Will it be awkward or unsafe in any way to use with a non-uniform bit profile? I don't want to ruin my first hang or loosen the head because every time I chop the head is twisting or torquing.

Leave it or keep taking metal off?
Thanks.

 

[Chignecto Woodsman]

Angle is your main concern. You can make a simple axe gauge from the image in "An Axe to Grind" (posted here, or just search 'axe gauge').

I have had a few axes with similar grinding issues/abuse, and only sharpened them to close to a proper angle as I wanted to save as much steel as possible. The only real issue with this is that there is potential for further damage and you really can't know if you're chipping or rolling the axe. With a good sharp edge and no damage you can easily tell how the steel is holding up.

That said, any steep angles could increase the risk of glancing blows, and too shallow angles could chip out. It looks fine to me and you can just check with the gauge and make the angles correct over time.

 

[1215]

Thanks. So taking into consideration splitting vs. cutting, same profile for an axe vs. hatchet? This is 99.9% going to be used to split firewood into kindling to be used in the fireplace, fire pit or the occasional restart of the wood stove in the garage/barn.

 

[SC T100]

If it's mostly splitting, I would keep at it with the file until the old grinding marks, even if it's not at the most accute of angles. It may not matter much, and is likely personal preference, but when I resharpen or re-profile a bit, I make sure I hit the entire bevel on both sides until they expose new metal.

It may be that the file you have isn't up to the job, or you weren't able to apply enough force. A nice big 10-14" file with the head gripped tighly in a vice should allow for enough pressure to get those marks out.

That being said...it'll probably work just fine for splitting kindling as it stands. I say try it out...if it works for you, great. And if it's bouncing or glancing, get the file back out.

 

[markv]

if it is sharp hang it and use it.
you don't need to eat the cutting edge away with a file or with stones or grinder.
use it to chop wood.
from my experince, most bits are not symmetrical. one side will be a little bit more convex or fatter than the other side.
nice Plumb bit😍
buzz

 

[Remzy]

I would give it a good profile myself, its better to live an honest shorter life than a croocked longer life, in my book