How to change from 90/10 to 50/50?

[slowtyper]

A couple of my knives started out with very bevels on both sides, but because of the way I sharpen (lazily), the right side has wide bevels and the left side has a small bevel. Not sure if its actually 90/10 or 70/30, but its quite drastic.

If I just concentrate mainly on the left side over time, they should even out, but they will both be wide bevels right? What if I wanted shorter bevels on both sides like the knife came originally? I was thinking change to a higher angle and sharpen both sides equally and eventually it would even out.

Am I making sense? Probably not.

 

[slowtyper]

FWIW the two knives I want to fix are a 270 Konosuke Gyuto and a 180 sakai takayuki petty

 

[Geo87]

Could you post photos?

Most likely your bevels have become wide because you haven't thinned the knife. Your primary bevel will be wide if it's thick behind the edge.

To make the edge 50/50 you need to work the left hand side with a coarse stone until it's even again.

To make your primary bevel small again you need to thin behind the edge evenly with a very low angle say 3-5 degrees. The primary will get smaller as you go. Keep going until it is very small and your knife cuts nicely again

 

[krx927]

To make the edge 50/50 you need to work the left hand side with a coarse stone until it's even again.

But I suppose this will push the edge of the knife to the right away from center of the blade? That would be an issue, wouldn't it?

 

[Geo87]

But I suppose this will push the edge of the knife to the right away from center of the blade? That would be an issue, wouldn't it?

I am only guessing without photos but from what the op is saying the edge used to be centred now it had shifted to the left by his sharpening the RHS too much . I am suggesting he recenter the edge by removing more metal from the LHS and then thin behind the edge evenly from both sides as it sounds like it needs it.

 

[Pensacola Tiger]

Before you do anything, is the knife steering? Has the cutting performance diminished? Or is this just a cosmetic issue about a wider bevel?

"If it ain't broke, don't fix it."

 

[slowtyper]

Yes, the knife is steering quite a bit (to the left). It still manages okay because I can adjust for it when using it, however I'd like to start looking at my sharpening more carefully rather than what I've been doing! I'll work on getting some pictures.

 

[JBroida]

maybe this will help... bear with the crappy video:
[video=youtube;8KMWcF2PiBQ]https://www.youtube.com/watch?v=8KMWcF2PiBQ&list=PLDgLV2bW_MlDT8kL7nOpnPGFMTvkrceLN#t=388[/video]