gunmike1 said:
... a good place to pick those up?
I used a digital scale with a high precision and recorded the results on a computer. I found that the results were no different than if I used a cheap spring scale which I picked up for $0.50 at a flea market.
daberti said:
why extremely polished edge should lose their sharpness very quickly?
If you are slicing then the cutting ability tends to be proportional to the size of the teeth, just like if you are sawing. The larger teeth not only take much more wear to grind them down to a smooth surface, they tend to be aggresive on multiple levels. With a really coarse finish the teeth actually have smaller teeth on them.
When would it be recommended the use of DMT ceramic whetstone?
You use really high polishes when you are push cutting. As you refine your edges more using steels which can take more acute angles, you will end up moving back towards higher polishes because really thin knives don't tend to slice materials as much as push cut right through them. Most of my EDC knives for example are ground at 5-10 degrees per side and I typically use high polishes. I tend to only use more coarse grits on some of the heavy duty knives which have bevels in the 12-14 degree range because if they are highly polished they don't slice well and with that angle and an edge of >0.030" thick, they don't push cut well anyway.
I tipically use my knives to slice cut meat, nylon bags, liquorice steaks (yellowish wet part), cardboard packages, packages seals, paracord, whittling wood for tindering.
For most general knife profiles, a lot of this type of cutting is best done on a draw/slice and thus benefits from a more coarse finish. However, whittling wood is pretty much all a push cut and thus works best at a very fine finish. Slicing ropes and whittling woods are like dancing and hiking, you either accept the performance in one is going to suck, or get decent, but not great, performance in both. For those kinds of tasks I would tend to carry at least two knives.
But as I noted, if you grind to really fine edges you will be able to go back to high polishes and see optimal performance. This however means a radical departure from the 15-20 degrees edges commonly found on most knives. If your bevels are of that nature then you really need some aggression on the edge (rougher finish) to get good cutting ability and edge retention.
I like the Spyderco medium ceramic and 600 DMT as two general purpose finishes. The 600 DMT is more towards slicing and the medium ceramic more towards push cutting and both are sort of inbetween in that they do nothing exceptionally well or exceptionally bad. They are what I typically finish knives to for example if I don't know the person very well. Then for example if they ask me to sharpen again I just ask them how it worked and adjust accordingly.
So if they say "The knife tended to lose the aggression early." I would back of from the medium ceramic and try 600 DMT. Whereas if they said "It felt a little rough during cutting." I would use the medium ceramic over the 600 DMT. Generally though most people who don't sharpen knives are so impressed by even the worst job you can do it is hard to get critical feedback because the knife easily outclasses anything they have every used even if you pick a really unsuitable grit.
-Cliff
Oh well, back to the sharpening stone.
