SAK Sharpening.

[Dan1982]

I can sharpen my sak to a razors edge however the more i sharpen it, the more it needs to be sharpened. (make sense?) it seems to dull very quickly and little nicks come off the blade with only moderate use. is there something obvious i am doing wrong?

appreciate your help as always!

Dan

 

[weaver]

You've got it too thin. Raise the back a might and thicken the edge.

 

[robin wood]

I think that is quite a simple one.

It is probably a question of the angle you are sharpening at. The shallower an angle you sharpen at the thinner the wedge the blade becomes and the "sharper" it is, great for cutting tomatoes, but it is also weaker and will chip or "edge roll" more easily. Edge roll is where the edge is thin and when you do some heavy work like carving a bit of wood a length of the edge folds over to one side.

If you raise the angle you sharpen at next time you will produce a stronger edge. The trick is to get the narrowest finest bevel you can get away with for the work you do whilst still keeping good edge retention. Normally I would say around 25-30 degrees..that is 12.5-15 degrees each side would be the area depending on what you do with it.

 

[robin wood]

Ah weaver typed quicker and said the same thing in less words.
Experiment

 

[Dan1982]

cheers for that guys. knew it would be something pretty basic and now i think about it that makes perfect sense! only recently aquired a sharpening stone so am still learning really. i was so impressed with the edge i managed to acheive that i didnt really think about the angle really. didnt occur to me until i had to use the knife quite a bit today and the edge lasted pretty poorly.

Thanks for that again.

Dan

 

[weaver]

Ah weaver typed quicker and said the same thing in less words.
Experiment

Finely honed wit and slow fingers combine to make posts short and to the point.