And no putting them in your mouth and blowing small amounts of sali…waitaminit…did he say that water changes their properties?..then what are they doing being used as mouthpieces?..yikes.
Okay, new theory. Putting my whistle back in its black plastic pouch that Mike provides while its still “moist” might be the culprit. I mighta wrecked it for good. Especially since I live in the mostly damp Bay Area…
I am glad I started this thread. I am learning stuff…
Hmmm - I wouldn’t go that far just yet - the water absorbtion is 0.25% in 24 hours. That’s not a lot, and it doesn’t proove anything about clogging. I’m only speculating in hopes someone with chemical engineering skills can add some definitive understanding. Any Chemical engo’s out there?
Like I said - it may be nothing.
Perhaps I should ask Dupont?
OK, I asked Du Pont.
I think I’ll change my family coat of arms to the Goat-Rampant-and-Windmill 
OTOH, it would be a great shame if it prooves that Delrin has problems - it machines just like hardwood and sounds similar to African Blackwood - better in my opinion. Metals corrode, woods can crack and move, plastics have other challenges - there are strategies to acomodate all that. Nothing lasts forever - it’s all a relative thing and I find it somehow comforting to have a relationship with my instrument beyond just picking-it up and playing.
Interesting, nay intriguing Watson. I’ve been playing my Burke black tip brass (extended delrin head) for about two years now every day and had only one problem - right after I decided to finally clean it even though it was playing just fine. I ran it under hot water and let it dry and it sounded different and crappy; then I used Adrian’s remedy - I put it away in a drawer for a few days, and lo and behold it reverted to its initial wonderful form. Really. I don’t know that these things either require or want cleaning other than to clear the windway if required with an index card piece or something, carefully.
But Peter’s right, never had this problem with my Gens; oh sorry, he didn’t mention Gens this time. 
Philo
Out of curiousity, did Mike replace the o-rings in the tuning slide when you sent it back? The way you’re describing the tone as “fuzzy” and unpredictable reminds me of leakage issues on a flute, which would either result from a crack or a leak of some sort. I wonder if after a few years of playing and tuning, there’s a leak at the slide due to a torn o-ring? Or maybe the tuning slide or socket is out of round? That could explain the late development and also why treating the windway doesn’t stop the clogging.
–Jeff
I’ve used delrin for several years for a varity of things and never really had problems with it. Yes, it will absord a small amount of moisture, but it releases it just as quickly.
One thing about it is that under compression it doesn’t really wear so much as gets harder. This is why a lot of people use it for nuts and bridges on stringed instruments.
Normal body fluids shouldn’t have any effect on the surface though.
I don’t know about the o-ring. To be honest with you, I don’t know how to tell if the o-ring is worn out and further, how I would get in there to replace it without scratching up the side walls if I did.
The thing about o-rings to me has always been, how can I wear out something I virtually never use? I mean, I have pulled the head out since this problem occurred a few times, but on the Eb, much less than my D whistles for example (as the Eb is the newest whistle I own). I have always wondered what the o-ring really does beyond keeping the joint tight for moving back and forth. I didn’t know that it would really affect the sound quality. Maybe that’s the problem? Hmmmm…
I’m wondering about spit and aluminum rather than delrin. Could they combine to create a coating or tarnish of some sort in the headpiece that would effect the tone but be water soluablewhen soaked?
I wonder if the problem would go away if the whistles were rotated, so that each one had a chance to dry out thoroughly between uses? Of course, the results would depend on how wet they get and how you store them.
Hmm. This hypothesis of water absorption doesn’t explain why the problem took years to appear, does it?
From time-to-time, I’ve heard from people who describe a gradual deterioration in the playability of whistles of various makes, but not in a way that’s allowed me to detect any pattern. I’ve got a number of Burkes from this era, but haven’t had the problem.
In fairness to Mike, we need to avoid letting this be a post-your-complaint-here thread. If you’ve had similar experiences, fair enough to post…but please also post if you haven’t. Normally, anybody who HAS had a problem is likely to post in this kind of thread and people who HAVEN’T are more likely just to move on without comment.
I don’t have a problem with this thread. Weeks has gone to great lengths to carefully describe the problem. But, Peter, this is a cheap shot on your part. You’re way out ahead of the evidence here.
I also play several Burkes from this era. No problems here.
I’ve also had a lot of pre-owned Burkes come through my hands. They consistently perform beautifully (sometimes after cleaning).
I’m not disputing Weeks’ problem…obviously something going on there. Just chiming in on the positive side of some really remarkable instruments made by a fine fellow.
Doc
I have three Burkes; one (DAN) i bought in 2004, and the other two (a black-tip brass C and an older WBB D) acquired through transactions on C&F. I play them fairly regularly and have never had a clogging or sound problem with either of the black tips. I do get clogging with the WBB which is similar to the Copeland i have – which i always attributed to the windway design and/or the brass/delrin combination, as Mike changed both for the blacktips and they’ve never been a problem for me.
I do find Dr F’s O-ring theory to be plausible – after all, they are IIRC made from rubber and are likely to degrade over time… more quickly than delrin, it would seem to me.
Testing the O ring in the tuning slide can be done this way. Put masking tape over the six tone holes and the fipple window. Put tape over the end or use your hand. Put water or water with a little dish washing soap in it around the tuning slide joint. Then with the holes and fipple window closed with tape, and tape or your hand over the end blow into the mouthpiece. If you see bubbles coming from around the tuning slide joint, there is a leak there. it only takes a very small leak to make a whistle play poorly.
I have an older DAS that I bought used a few months ago. It’s never had a problem. The O-ring theory makes sense to me also. These are great whistles, and I’d like a brass C at some point.
I also have three Burkes, the WBB D I was talking about earlier in the thread, an AlPro D which I bought used, and a DAN that my wife bought from Mike himself for a Christmas present for me.
The only Burke that’s ever given me a bit of trouble is the WBB which I bought in an Ebay auction…and since I did the waxed dental floss thing, it’s fine.
The other two are consistently fine, dependable whistles. And the tone of the D narrow bore brass is just outstanding…this whistle’s tone does for music what melted butter does for popcorn.
The AlPro has been dropped on a concrete floor a couple of times, and it’s my general bang-around workhorse whistle. It still plays beautifully.
In my experience, Mike Burke makes some very fine, dependable, and durable whistles.
–James
I just checked and I got my Brass Pro Sessions in May of 2002. It’s got the brass top on the mouthpiece with black below. I’ve never had a clog in the thing, ever. Oh, and I haven’t bought another whistle since I got it(and all without a 12 step program too!) 
I’ll try it! Thanks!
Ofcourse it was a cheap shot and so cheap it should have been obvious to anyone how tongue in cheek it was. And I don’t think anyone except yourself took this serious for even a second. So come on, lighten up a bit there Dale.
I decline to lighten up and, in this case, I’m not really buying the I-was-just-kidding thing. I’ve already said that I think Weeks’ post was entirely legit and worthwhile for this board. But, the need for fairness is not trivial here. A lot of whistlemakers, including Mike Burke, invest a lot of time and money in their businesses and so this discussion is pretty darn serious to those guys, I would think, and they have something to lose in all of this.
In this case, you’ve got a track record of commentary so that readers know where you’re coming from on the expensive whistle issue, so you and I are both right in characterizing this as a cheap shot, “tongue in cheek” or not.