I tweaked an Oak D with blue tack. After shortening the lip until the sucker wouldn’t play at all (oops!) I applied a thin piece of plastic (from a coffeemate bottle in this case) and turned that whistle into a beauty. Now I discover that it’s flat as a pancake, even with the fipple pushed down all the way on the barrel. What about taking a piece off the barrel at the fipple end? Would that sharpen it? I think it would help, but would it negatively affect how in-tune it is with itself? I’m about 30 to 40 cents flat.
Flat as a pancake suggests that it got run over by a car. If it just plays flat, then I know some people with whom you’ll sound great. Actually, I can’t help you. But I do know that if you buy five more Oaks, probably 2 will sound great. Why people don’t buy more Oaks to find the “good one”, is beyond me. They do it with countless Generations. Pat O’Riordan once told me that if I had an Oak high D, then I really didn’t need one of his high D’s. I think he likes them. So do I.
JP
Well, taking a bit off won’t hurt unless you booger up the end so it won’t slide into the mouthpiece. I think you can also do something like flare the end of the whistle but this will only affect the tonic note. - Joel
Editted to add: do a little at a time and use a fine file or sandpaper rather than a hacksaw or tubing cutter.
[ This Message was edited by: joeln on 2002-10-09 09:04 ]

Sliding a piece of piano wire (obtained at hobby store) down into the the duct will help unflatten the windway. You can use differing gauges of piano wire to open the windway to a desired amount. You can grab both ends of the wire and slide them about to re-inflate the impacted windway.