Hello. I have a Sindt high D that I’ve owned and liked for about 15 years. It’s one of the 3 or 4 various high Ds that I consider my main whistles for gigs. Several weeks ago the tonal clarity started becoming rather breathy and raspy. I’ve played whistle for about 20 years and always try to clean them before playing a gig. In this case, cleaning doesn’t seem to be a solution to the problem and I don’t see damage or scratches in the windway or any part the mouthpiece, so obviously something else is going on that I can’t see. This not a reflection on Sindt whistles as they are always made so well and I’ll be ordering others from him.
I was wondering if anyone has had a similar experience and would like to hear your thoughts on this.
No expert here, but do have a Sindt whistle as well. I recently cleaned out the windways on my Sindt and an old Generation thoroughly and found there was an improvement in tone (used soapy water and a long soft nylon bristle brush to get into all the crevases). I think you will be surprised at how much lint and dust can build up in there over the years. Only other things I can think of that might have an effect would be some kind of distortion to the labium (though you say it looks clean) and, possibly, a leak in the headjoint seal. Can’t remember right now if John uses an o-ring, but you might check that and replace it if it has degraded over time.
I haven’t got one, but do Sindts have o-rings in the tuning slide? Is it worn and leaking? If so, does adding cork grease help?
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I’d take a soft pipe cleaner and some detergent to the windway anyway. I’ve seen muck accumulate on the sides of the windway that are not visible by looking through the end. I’ve also seen grit accumulate on the bottom of the blade which is hard to remove with a brush. Send it back to John. He’ll take care of if for you and probably won’t charge you more than shipping. Any whistle maker will usually do this for you and I’d not take the chance of damaging the blade area thereby ruining the whistle.
ecohawk
No, there’s no O-ring. The slide is metal-on-metal contact.
Bang the block out, clean the windway surfaces with a soft toothbrush, re-oil, shove the block back in.
It doesn’t have an O-ring. All the delrin areas & seams are clean and tight and no damage to the blade. I’ve used various cleaning methods, but it won’t hurt to do it again. I haven’t seen any soft nylon brushes small enough to fit through a whistle windway, but I’d like to find one.
I think I’ll pass on banging the block out.
benhall, you may have hit on something there with the cork grease! I do usually use a little grease with that whistle as the body sections I used fit very tightly. In fact about a month ago I did turn down the two bodies very slightly so they could be adjusted easier and haven’t used any grease since. That shouldn’t have been a problem as they still seemed tight enough and I couldn’t detect any leaks, but I’ll certainly give it a try and see what happens.
Given the pinned construction of the Sindt head, I’d pass on that, too. 
For the windway, you could try the butt end of a paper match. When you tear it off, the end forms a little “brush”, and it’s soft enough not to damage the Delrin. If you approach the windway from both ends, you should be able to clean the entire length.
Aren’t the Sindt blocks pinned?
The Delrin and brass are tough materials. You could even soak the head overnight in soapy water, then clean the windway with a pipe cleaner. Rubbing alcohol could be used to dissolve tougher gunk. I’ve had whistles in for revoicing whose owners are smokers, and things can get pretty ugly in there.
It appears that a tiny bit of grease is the solution. I’d completely forgotten that I had turned down the slide areas of two body sections several weeks ago to allow for a more easily adjustable tuning slide and hadn’t bothered to grease the joint. So even though it’s still pretty snug with no detectable leaks, I greased it anyway and it is playing a better.
Funny thing, though, I’ve got some Generation whistles that I’ve tweaked and on a couple of them the mouthpieces are so loose that they almost wobble, but they play as sweet as any I’ve ever owned.
Thanks for your replies and suggestions.
I mentioned the grease because it helps on my high D Reyburn. Thought it might be the same. Glad your whistle is playing better.