Hi, Steven
My take on the matter is that no knife edge should ripple in dried bamboo even if the user intentionally twists the edge in the cut and the cut happens to be through one of the nodes (i think you refer to them as 'knots') on the cane. This is, in fact, exactly what I do during some phases of testing. Cutting dried bamboo is much harder on the edge than green bamboo (the condition, not the color), of course, but still not a big deal at all. Pine knots... big gnarly pine knots... are on the order of several magnitudes harder on an edge than bamboo, dried or otherwise. I grow four varities of giant bamboo along with rivercane, just for cutting purposes, so I have some experience with the stuff.
There are more than one kind of *test* when cutting. One kind would be to see how much bamboo the blade will zip through and how easily it does so. That would be the 'showmanship test'. The other kind of test is purposely destructive in nature. No attempt is made to go through the bamboo... rather an attempt is made to destroy the blade *in* the bamboo. A broken or severely twisted blade might be a possibility if the blade were traditionally Japanese... or if it were a blade of modern steels with a hamon that was too narrow... but that scenario simply would not happen with a blade that was heat treated in a proper manner with a wide enough hamon to provide strength to resist twisting / bending.
When rippling does occur it is usually because the maker has thinned the edge down too fine in an effort to get better cutting results. During one of Matt Lamey's early visits here, he had one blade (of several he brought with him) where (and I mentioned it to him) I thought the edge was too thin. In standing wood of all kinds (even in knots) the edge held up fine and cut, as many people now say, "like a laser". When tested on the dried bamboo, the edge rippled. The ripple was not obvious to the eye and barely to the touch... but was very obvious when a diamond hone was taken to the blade. Matt took the lesson to heart and with very good grace. *Some* amount of cutting ability must be sacrificed to increase edge durability, even if the heat-treat is right on the money. That's a shame, but it's a fact of life that must be taken into consideration.
I'll post a link to an example of a blade that would cut standing hair, cut a single inked letter off newsprint without going through the paper (Don Fogg did this cut and can be asked about it. I believe almost everyone in the knife world knows that Don's word can be taken at face value.) The same blade with the same edge also went through a bundle of dried bamboo when swung (by me) with both hands and sustained no damage whatsoever. Not all cuts through the bundles, which Don laughingly named 'Alabama tatami mats', were successful. The blade twisted badly in some of the cuts and would stop a cane or two short of going through the bundle.... and when I say twisted, I mean it twisted in my hands, *not* that the blade came out of the test with a twist or bend. The bamboo in the bundles was what was commonly called 'river cane'... same old cane poles used for fishing... which are considerably more difficult to cut than the larger diameter canes of the giant bamboo. In a given size bundle, the small cane presents more wall material to be cut than larger diameter cane in a 'same sized' bundle. And because the blade must exit one cane and enter another while going through the bundle, the cut is a very difficult one to make. On one cutting attempt, the blade turned downward on the last, or second to the last cane, and traveled down toward a metal pipe which held the bundle of canes and actually pinged into the pipe before I could stop the motion. I expected a tiny chip, but there wasn't one.
Don did some pics of the cutting... including a rolled up cigarette paper in his shop... which can be found here:
http://www.dfoggknives.com/Cloud Cutter.htm
Follow the links to the cutting tests.
All of this horn tooting is not for the purpose of trying to sell my knives. I have more requests for knives than I'll ever fill. I pass these experiences along as *information* about what a blade should do and there are plenty of blades out there at this point that should cut the bamboo easily with no rippling, twisting, bending or chipping.
Matt was a collector before he was a knifemaker. He's spent a good deal of time working in my shop... as well as testing his blades here... because he liked the way my blades performed and wanted to duplicate that performance in his own work. He spends as much, and perhaps more, time testing his work than any other maker I know personally... although there are a number of makers out there who seriously test their work both in private and in public. I don't think you'll find a Lamey knife whose edge will ripple in dried bamboo no matter how badly the cut is executed.
This in no way is meant to detract from the usefulness of Shiva's work. With each knife a choice is made as to edge geometry, heat treat, etc. Every maker chooses their own path on each knife they produce. A thin enough edge on one of my blades, or Matt's, or anyone's blades who uses a good steel that is properly heat treated will result in extreme cutting ability at the expense of durability. Every blade is a juggling act and every factor must be taken into account for a maker to produce the best knife he can. And 'best' can be defined differently by each maker. In my opinion, although it takes a lot of time / energy / material to do it, *every* blade should be tested in a very strenuous manner before being shipped to a customer. No exceptions.
None of the above is aimed at you in a negative manner, either, STeven. I suppose, being the loud mouthed maniac I am (at least during those times I'm not comatose), that I had to stick my two pfennings worth into this thread (and inflation needs to be factored in) stating my personal point of view.
YMMV!
Old crazy Jimmy
ps... Matt called me a few minutes ago and said you and he (STeven) had a good yak on the phone. Info exchange is always a good thing.:thumbup:
... except for one thing: I've studied those pictures of the rope cutting very carefully and I believe Beaucant actually did make it through 16 pieces of rope. Personally, I don't care for the man worth a flip... having had some exchange of letters with him back in the early 80's, if memory serves.... BUT, his form in those pics is excellent... he's putting every ounce of energy into the cut he can muster and he has a sharp blade. The pieces of rope cut seem to be in proper relation to the bundle of rope if you take into account the position of Beaucant's knife holding hand. That said, I have to admit to having been fooled more than once in my life.
