Sorry, I don't see the analogy.
I wasn't asking how a knife wears.
Perhaps I didn't ask my question very well so let me try to illustrate.
Let's say a knife has a hardness of 60 HRc. At the top of the spectrum we have glass and granite. Let's assign an arbitrary hardness of 100 HRc for them. Since glass and granite are much harder than the knife, those materials are detrimental to the knife's edge. I don't think anyone hear would argue with that.
Now looking at the the other end of the spectrum, wood and polycarbonate. Both are too soft for the Rockwell C scale. So let's just switch to Rockwell B and arbitrarily assign a value of 20 HRb to wood, well below 0 HRc. We generally consider wood to be a preferred material to cut on. So where does poly fall? If the hardness is near that of wood, then the two material should perform near equally. It seems to be generally accepted that poly is significantly harder than wood and therefore more detrimental to an edge, but is that true?
But the wood part of the equation is complicated a little by the use of resins and glue. What is the hardness of the resins as compared to the wood and poly? I would think that the resin hardness is about equal to that of polycarbonate so I would not think there would be much difference between the two. However on these Epicurean boards the consensus seems to be that because the resin content is so high, the boards are hard on knives.
The silica content of bamboo is an excellent point as mentioned above and kind of differentiates those boards.
It seems widely accepted that these Epicurean boards are significantly harder and therefore knife contact should be light. I'm wondering if that is just an assumption that has been taken as fact. I haven't seen anything to support it and if the resin hardness is on par with polycarb then the two styles of boards should be about equal.
Good question AJ, I'd like to see the answer also. I was just commenting on your statement that a metal bat getting dented by a baseball is an "energy transfer issue", not a hardness issue (like the knife and board issue is).
OK. Well the baseball is thrown with velocity giving it kinetic energy. When it contacts the bat the kinetic energy is transferred to the bat resulting in material deformation, a dent. At the same time the bat is swung with velocity giving it kinetic energy. When the bat strikes the ball the kinetic energy of the bat is transferred to the ball sending it out into the out field.
Originally Posted by Andrew H
In the case of the knife striking the cutting board, the cutting board has zero kinetic energy, it does not transfer any energy to the knife. The knife in a downward smack possess kinetic energy which is transferred to the board and back into the users hand in the form of shock waves.
So see, I don't see an analogy. Maybe it's just me. Sorry to get this so far off track, but I must not have worded my original question well.
"In the case of the knife striking the cutting board, the cutting board has zero kinetic energy, it does not transfer any energy to the knife. The knife in a downward smack possess kinetic energy which is transferred to the board and back into the users hand in the form of shock waves."
Which was some of where my question origninated from that the cutting board depending on density / hardness / reflextivity absorbs some of the energy from the knife.
But my main question was really about how the composite nature of the board and the factors noted above affect the sharpness of a knife?
Might not happen soon, but a test may be in order to compare an epicurean board to other materials.
I'll muddy the waters a little here. I think an Epicurean board rolls an edge easier then an end grain board because the edge does not bite into the Epicurean as much when it strikes the board at a slightly off-angle.
How to break that down structurally/ physically? I guess it's more of an inelastic collision vs/ elastic, so more eccentric force is applied to the thin edge.
I have no hands-on experience with bamboo boards, so my best guess is they typically have more glued joints and the chipping may be from stress concentration points where the glue is slightly higher then the wood surface. And that guess is worth exactly how much you paid for it :wink:
Solution: Karring, use the Epicurean boards like it's going out of style. Tell us what you think. We will believe you.
No need to shot bearings at it!
Originally Posted by johndoughy
LOL. The irony is that I just happen to be cutting on one as I write this, and a minute ago I was sawing into it with my miyabi paring knife just to how it felt when scarring the board. I remember when this issue came up a couple years back, I actually took a crappy knife and dropped it tip down from a set height just to see how far the tip would penetrate all my different boards.
That is some serious skill! Cutting, surfing KKF and typing at the same time, very well done! The word addicted comes to mind. :Stefan:
Originally Posted by mr drinky
I love using that smiley, it has so many uses here.
I will still maintain that for home use, while my Boardsmith is my prefered board, the epicurean boards are not as bad for the edge as they are being made out to be. I have no data to back that up, but in the long run, don't we all need more practice sharpening anyway. My home knives hit the stones every other week so the correlation between edge abusiveness and the board never really entered into play.
I started a thread like this one awhile ago and I'm sure that there where many before that and they all seem to end. In the same place: no one really knows / has done a scientific test on edge wear on end grain company epicurean but the 2 are probably close enough that the decision comes down to other factors like application, cleanup, feel, appearance and personal taste.
Like most nuts on here I have end grain. Maple, poly, and epi.
However, I recently got a screaming deal on a massive epi "big block" series board... It's 26"x18"x1" thick. My reason for getting it was that my endorsing board had previously been living on the counter and by the sink and taking a lot of abuse /water /missuse. Being as near indestructible as any knife friendly surface can be, the epi made a much better "always out" board. It takes hot pans, but water, oil, blood, sticky goo, vinegar, food coloring, red wine... and it just shrugs it off and asks for more.
For long cutathons I still bring out the end grain. I enjoy cutting on the natural wood more... It just feels nice. Wood also seems to have much better dampening properties (absorbs/deadens shock).
However, I have to say that while the epi looks and feels harder, it still cuts and scores and I haven't noticed a difference in edge retention since I started using it more.
Can't agree with this. You can hold a baseball bat still and dent it with a ball--the ball just has to be moving faster to have enough energy to generate the same effective work. And the ball will rebound off a bat that isn't moving--think of little kids holding a bat still and getting a "hit" when a ball hits the bat and bounces off.
Originally Posted by ajhuff
You can hit a cutting board with a knife or hit a knife with a cutting board--or have them both in motion--the same kinetic energy will generate the same force on the blade for a given cutting board. As long as the resulting energy is the same, the origin of your coordinate system doesn't matter.
The material properties of the board, on the other hand, will affect how much of the kinetic energy is dissipated through damping, vibration, friction, etc. Hardness isn't the only property that will affect the forces on the knife blade.
That said, the store where I bought my knife advised against using Epicurean boards.