There is absolutely nothing wrong with ceramic for a Ka-bar. You can use a sidewalk to sharpen if needs be (not the easiest option in the world, but I've proven it to a couple people over the years). Ceramics, in general, do not cut as fast as diamond hones or water stones but there's nothing about ANY of them that is inherently "bad" for a knife. Sharpening incorrectly is bad for a knife, but the tool used to sharpen incorrectly with doesn't make a difference. The people who say different are either ignorant or trying to sell a sharpener of their own---I'm usually not an absolutist and am open to other people's opinions but stuff like this is just blanketly untrue. What you do NOT want is any kind of department-store type sharpener that you pull a knife through, or that uses carbide wheels, as these are actually ripping hunks of metal off as opposed to grinding it away, and will (not might, but WILL) create chips and fractures in your edge that will hamper cutting performance and overall longevity. Overall, honestly, I do recommend against carbide blade sharpeners in general, just because again they're cutting the steel instead of grinding it, and it's easy to dig too deep and weaken your edge. Whatever you use, though, stick to it and focus on maintaining consistent angles. There's nothing hard in the least about sharpening, it just takes practice to develop muscle memory. If you have two different grits of sharpener, always stick with the coarser one until the edge is shaving sharp, or damned near, and leave the finer hone for refining the edge right at the end. A very common mistake people make is moving to the fine hone too early.
