High polished busse, lets see yours

[Father & Son Traditional Sharpening]

Thanks for the reply and I hear you -- I've heard a lot of people rave about convex grind down to true zero. However, I prefer (due to maintenance and consistency) a V - edge. Now I knock back the shoulders on all my Busse knives. There's no question the grind is important. However -- I don't see how much of a difference it would make to have it convex to zero vs convex to V with shoulders knocked back. Let me know your thoughts.

What you basically have with a full convex grind is a constant increase in angles going from spine to edge. Starting from basically zero at the spine and getting rather obtuse towards the edge depending on the radius of the convex. IMO, full convex grinds should (mostly) always terminate in a zero edge because they've already become obtuse once you get to the edge.

Case in point, the SAR series were full convex with a secondary convex grind…. this made the effective edge angle insanely obtuse and really destroyed any cutting abilities it may have been capable of with zero grind. Now the Basic 8 has similar geometry to this, only with a larger (flatter) radius so the effect of this is somewhat muted. I will be taking my Basic 8 to true zero soon, it's in progress so I will be able to document the differences.

The problem is not convex to zero vs. convex to v as you put it but rather, convex to zero (no secondary bevel) vs. convex to secondary (v or convex). Full convex grinds don't need secondary bevels IMO, adding one will only severely compromise cutting abilities with little added strength.

 

[tinfoil hat timmy]

The sjtacle I sold a while back didn't LOOK sharp, but MAN. Could that thing go! I've gotta say I like the look of the satin full convex to zero.

 

[Rob_Mob]

What you basically have with a full convex grind is a constant increase in angles going from spine to edge. Starting from basically zero at the spine and getting rather obtuse towards the edge depending on the radius of the convex. IMO, full convex grinds should (mostly) always terminate in a zero edge because they've already become obtuse once you get to the edge.

Case in point, the SAR series were full convex with a secondary convex grind…. this made the effective edge angle insanely obtuse and really destroyed any cutting abilities it may have been capable of with zero grind. Now the Basic 8 has similar geometry to this, only with a larger (flatter) radius so the effect of this is somewhat muted. I will be taking my Basic 8 to true zero soon, it's in progress so I will be able to document the differences.

The problem is not convex to zero vs. convex to v as you put it but rather, convex to zero (no secondary bevel) vs. convex to secondary (v or convex). Full convex grinds don't need secondary bevels IMO, adding one will only severely compromise cutting abilities with little added strength.

Ahh thanks for the proper explanation --- I could be wrong here, but I wonder if the added performance of convex to 0 is noticeable enough to outweigh the slightly weaker edge of a true zero edge compared to a secondary V. I'm thinking edge rolling is quicker and more likely to happen than edge rolling with a secondary bevel. I know that INFI is tough enough for a full convex to zero --- but even so I imaging micro rolling deformation to be more of an obstacle/performance hindering component compared to a secondary V. Also, for me it's easier to sharpen with a perfectly consistent edge when applying a V edge. I'm sure someone much more experienced than I am can chime in and correct me if I'm wrong.

Edge geometry of a zero edge convex (which actually has less material) should theoretically be more susceptible to lateral deformation (micro rolling). I imagine for a one time use or a competition cutter -- it would indeed be better performing to have a convex to zero. However, for prolonged use --- the secondary bevel should more effectively resist lateral deformation.

 

[mckrob]

 

[Garth Reckner]

Sure are some pretty blades in here.

Garth

 

[Father & Son Traditional Sharpening]

Rob Mob, I really think that you'd be hard pressed to tell much difference between a true zero or secondary bevel in terms of deterioration…. for anything less than extremely abusive cutting. You will without a doubt notice a significant improvement in the cutting abilities however and IMO the tradeoff is well worth making unless you plan on chopping cinder blocks often.

 

[jfever311]

Boss Jack proto DC finish I put a 30 Degree inclusive mirror polished edge on it with a KOWS and an old leather strop


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[Icky Thump]