Reprofiling: How do you know?

[Bugout Bill]

I recently purchased a CRK Star-Tac, and I am not terribly satisfied with its edge. I am planning on reprofiling it down to 30 degrees. I have reprofiled a few other knives, but I have always struggled with determining when the edge has been thinned out to the appropriate angle. I have only done this while freehanding, although I also have a Sharpmaker. Any suggestions or input would be greatly appreciated. Thanks.

 

[StevieWunders]

How much time have you got to devote to this? I'm an old hand-only-sharpener myself. Nothing against mechanical stuff; it's a matter of time vs. pleasure. Since I always worked with my knives, I determined bevel and sharpness by trial and error on the job. If the steel chipped or rolled-too fine an edge or too long a bevel(too small an angle). Or too cheap a steel. Or too thin a slab to start with. If the edge doesn't bite into the stuff you're trying to cut, narrow the angle some (gradually) until it does. It takes time. And actually using the knife for its intended purpose. It doesn't take a lot of technical know-how or money. In the process, you'll learn some things about what you and your knife are capable of-a potentially rewarding experience.

 

[ConBon]

Well Stevie has the right idea for finding out what angle to get going, but if you already know the angle you want, my advice is to make a square edge by "cutting" cement. I guess that's technically a 180 degree inclusive edge but that doesn't matter. Then if you know what angle you want, say 22 degrees inclusive, get a protractor, pen, and piece of paper and plot two lines that intersect to form an 11 degree angle, as this is what you will hold the knife at while working on the stone. A bigger stone works best, but whatever you feel comfortable with that's a low grit and won't wear down fast is best. Just put the piece of paper with your angle down nearby, so you can reference it and check your hand angle while working. Now you just need to keep a steady hand, work evenly on each side (assuming you want a "V" edge), and be patient!

Cheers and Good Luck,
Connor

 

[HwangJino]

I usually go a tad wider bevel than how it came.

meaning the edge would be weaker but sharper. However a microbevel adds strength if you know how.

 

[Minibear464]

If you are thinning it out, then just do it! You'll reduce the shoulders of the bevel, and you can tell you are done when the edge is sharpened and you have a burr- this is when the lower angle completely replaces the previous edge. If the knife was a little dull in the beginning, and you continue to sharpen at the thinner angle, then the knife will have reached that point when the edge is sharp. If that doesn't really make sense- you know when you can sharpen the knife using the new angle.