sharpmaker and convexed edges

[ipm]

can a convex edge be sharpened on the spyderco sharpmaker?

does anyone have experience with this?

 

[ExMachina]

sure...it just won't be convexed anymore

 

[miro44]

Yes it can. I' ve been sharpening my Fallkniven S1 on my Sharpmaker with the 40° angle and it' s been doing fine. Only thing is that the edge will with time just turn into a regular "V" grind if you' re ok with that.

 

[smcclown05]

If you lay both rods down flat in the holder and use it like a bench stone you'll probably be able to maintain the convex edge. Many people (like me) can't maintain a perfect angle when sharpening this way so beveled edges end up at least slightly convexed anyway.

 

[Will Power]

I have say I've found the convexing thing to be time consuming and I'm still not good at it.Often scratch up the blade without much effect, so I might try the Sharpmaker with the rods left flat.

 

[Phillip Dobson]

I like to convex my edges (on stones) and then maintain them on the SM. My goal is 30-degrees at the edge, convexed back to (almost) the primary grind.

It is possible to maintain this edge indefinitely, using only the SM. Start with the knife vertical and bring the edge back to the desired sharpness (standard Sharpmaker technique). Then, incrementally bring the spine of the knife closer to the stone. This will remove material at a more acute angle, thereby smoothing the shoulders.

I like the consistency this provides. I always know the the edge is exactly 30-degrees (or whatever angle I prefer). It also makes touchups very easy, because you have to remove very little material from the very edge.

 

[Will Power]

Very interesting advice ,thank you Phillip Dobson:thumbup:

 

[Sal Glesser]

I have used Phillip's method and agree that it works acceptable well. The purpose/function of the convex edge is to reduce friction in the cut caused by the sharp(er) edge of the shoulder.

The same concept applies to grind lines and spine edges. The cross section of the traditional Japanese sword deals with these issues.

A slack-belt grinder, soft buffing wheel, or even a mousepad covered with fine emery paper works to maintain one.

Convex edges are often difficult to maintain and I find myself going to a wide full flat grind with a very thin edge.

sal