Author: huboboe
Date: 2012-07-19 20:25
OK, I've gotta add some comments from the perspective of a manufacturer as well as player/reed-maker...
PART I:
The chatter marks Loreee BF51 refers to on his EH tip were no doubt caused by using a knife blade that was harder than the shaper tip was. The old tip makers, Brannen, Pfeiffer, Bhosys an the like made tips in small batches, usually out of oil hardening tool steel and hardened them themselves. (Heat to cherry red and drop them into an oil bath to cool.) That process (Also used to harden the handmade knives of the time) was spotty and a bit uncertain, since the 'cherry red' temperature is subjective, so the ultimate hardness was uncertyain. Factory made knives have always been commercially heat treated where heating and quenching temperatures are controlled and the resulting hardness known.
My knife blades and shaper tips are made in large enough batches to justify the cost of commercial heat treating and both are hardened to RC 60 - 62. They could be made harder, but that would result in unwarrented brittleness. (You wouldn't want your knife to shatter if you dropped it!) It is true that a slightly softer steel will dull more quickly than a slightly harder one, but it is a myth that harder steel is more difficult to sharpen. The stone is so much harder than any useful hardness of tool steel that the difference is unnoticeable.
I don't know about the practices of my colleagues in the business; perhaps they would like to speak for their products here...
I use single edge razor blades for shaping. I do not try to take off large amounts of cane at a time, but just what can comfortably be removed each pass, so that when my blade arrives at the shaper, there is only a little bit to remove on the final pass. This has two benefits:
1) Single edge razor blades are hardened to RC 62, so long term, aggressive use of single edge blades will result in wear to the shaper tip, no matter who made it.
2) The edge of a razor blade is very thin. If you use a lot of pressure on that last pass (trying to cut a thick sliver of cane) the edge will distort, bend past the flat edge of the shaper and the resultant product will be narrower than the shaper tip. This will also occur if you tilt the blade rather than having it flat on the shaper edge. This is more likely to happen if you are using a lot of pressure.
I also use a fresh portion of the edge for each pass that contacts the shaper tip, so I get, at most, two pieces of shaped cane per blade. If you buy blades at the local paint store in boxes of 100, this is not a significant expense, but it does assure clean, fresh cuts on the cane that don't leak.
Box cutters, disposable break-off blades and the like are also hardened to RC 62 and above and have a handle which allows even greater pressure to be exerted pressing against the shaper. They offer more control, but unless used delicately on the last passes, they will also cause wear to the tip.
They are also harder to change, so you are likely to continue shaping with a dull blade, causing fuzzy edges on the cane which are more likely to leak.
Thus endeth Part I
Robert Hubbard
WestwindDoubleReed.com
1-888-579-6020
bob@westwinddoublereed.com
|
|
The Oboe BBoard
.jpg){kind=small}
