Chiff and Fipple Forums

I have an Olwell six-key, recentish acquisition.
When the humidity goes up to fifty or more the C natural
key sticks in the channel. It opens but won't close. My
assumption is that the wood is expanding and 'seizing'
the key in the channel. (Betcha this is why some makers
use silver channels.) I've removed the key, cleaned it, oiled
the pin, etc., and also gone over the sides of the channel with
sand paper (but not very vigorously). The sticking continues.
Will some of you more experienced people give me some advice
as to what to do? Being careful. Thanks.

Jim: I would have assumed the same thing. Could the key possibly have been bent? I would suggest that you seek Mr. Olwell's advice at this point.

You fail to mention the type of wood Jim, so I assume Blackwood, not Boxwood. Olwell Blackwood flutes tend to be pretty stable, but expansion and or minor warping of the key channels is always a possibility. That said, a bent axle pin is always the first thing to rule out, particularly on flutes from previous owners or flutes that have ever been serviced - axle pins are notoriously easy to bend upon removal or installation. Bent pins can cause binding/sticking keys several ways, one of which is by skewing the key in the keyway enough to rub on one or both of the key channel sides. Many a flute has had its key channel blocks sanded or filed down to alleviate key rubbing, only to later end up with sloppy key action when the bent axle is finally diagnosed and replaced.

Similar problems can occur when a pin is put back in the opposite direction, that is to say installed from the opposite side to which it was originally fitted. Sticking problems can also occur when the pins get mixed up during disassembly for cleaning or repadding, and a pin from one key block is used where another used to be.

Slightly bent keys can (obviously) also cause sticking.

Personally, I’d start by contacting the Olwells and asking them to mail you a couple of new axle pins for the key in question, should be a standard size for them. Also ask if the axle and or axle holes are tapered in any way to prevent installation from the wrong side of the blocks, some makers do this. Replace the current pin with a new one. Try installing it from the correct side and see if things are better. If not, and the Olwells have stated the pins and holes are purely cylindrical, try installing the pin from the opposite side.

Still not better? I’d send the flute to the Olwells for inspection at that point as you probably will not be able to determine if the key is ever so slightly bent, or if there are indeed a combination of things causing the problem. Sure anyone can sand away some wood, but few can do it and keep the key channels perfectly straight. I’ve seen flutes go from having a minor sticking key issue to having a major and permanent wobbly key problem thanks to inexperienced home sanding and or filing. Spend the money to have the Olwells sort out the issue, rather than (more or less) permanently ruining the action of that key.

JMO, YMMV, blah, blah, blah.

Thanks. Much to think about. When humidity is lowish the key works fine.
These suggestions never occurred to me.

I would second the recommendation to contact the Olwells before doing anything else.

That being said I had this same problem with my Gallagher flute and John told me (in person, he was in Portland and I asked him)to take a nail file and, making sure it was flush with the block, sand the inside of the block, this was also a few months after it had been back to him for some re-padding etc. so everything else was ruled out already. I did this making very slight adjustments until the key stopped sticking. Hasn't been a problem since but I would not have done it had John not told me to do it. Just sharing this story as it is relevant, I still think it a better idea to talk to the Olwells first. Also, my flute is dogwood which is much more susceptible to expanding and contracting with humidity than blackwood.

Thanks. If I learn anything I'll report back.

jim stone wrote:I have an Olwell six-key, recentish acquisition.
When the humidity goes up to fifty or more the C natural
key sticks in the channel. It opens but won't close. My
assumption is that the wood is expanding and 'seizing'
the key in the channel. (Betcha this is why some makers
use silver channels.) I've removed the key, cleaned it, oiled
the pin, etc., and also gone over the sides of the channel with
sand paper (but not very vigorously). The sticking continues.
Will some of you more experienced people give me some advice
as to what to do? Being careful. Thanks.

Hmmm, interesting, Jim. Theoretically, increased humidity should increase the gap between the cheeks of the block, not reduce it. But that assumes a homogeneous material, which wood isn't. And it assumes the moisture is evenly distributed, which it's unlikely to be. So theory isn't going to help us much here. Damn't.

While you await hearing from the Olwells, here's a few more things to try:

- replace the pin with a thin needle, straightened paper clip or dressmaker's pin. Not a solution, just an experiment.
- clean off any gunge on top of the striker plate (the slip of metal between the block cheeks)
- grease the tip of the spring where it contacts the striker plate.

Any change?

Can you detect any resistance when you manually open and close the key?
If not, could it be that the spring has simply lost interest and needs to be reset? (Add a light rubber band around the flute near the key cup - does that return normality?)

Incidentally, the silver channels you mentioned were sometimes used by 19th century makers. The slot in the block is made oversize but then reduced by inserting a U-shaped liner of silver. Sounds like a good idea, but:
- I've seen 19th century flutes with splits under those channels, no doubt caused by the wood wanting to shrink and the metal preventing it.
- silver on silver (i.e. silver key on silver channel liner) is not a great bearing surface. Dissimilar metals or materials actually make better bearing surfaces.

Looking forward to hearing what you discover!

Ah, now, another thought. Is it possible at all that the key has got bent? Even the smallest amount can really inhibit free movement of a c key or a Long F key because of the guide blocks. Again, you might be able to detect it when you manually push the key open or closed. Or by removing the pin, then removing and replacing the key. Any resistance?

You might like to try this trick too. Remove the key and paint both sides with marker pen, just around the areas where the key enters the two blocks. (Unless you happen to be a machinist and have a ready supply of Engineer's Blue, in which case use that!) Leave it a few minutes to dry, reassemble it onto the flute and operate the key manually a few times. Take it off and look for where the ink has been worn off. Does that tell us anything?

Thanks, Terry, and everybody! I'm swamped in work at the moment,
but I will return to this when the deck is clear. (I'm refereeing papers
for scholarly journals, a good number of them now that I'm retired
from explaining obscure ideas to uninterested people.) Grateful everybody--this is
all very helpful in getting a grasp on how to proceed.

I said I would report back. I received info from the fellow who sold me the flute
that it had never been played. This helped make less plausible the idea that the
key had somehow got bent. Also it travels smoothly in the channel when assisted by
a rubber band. So I followed some of the advice earlier in this thread and took
a nail file to the sides of the key-channel, upbraiding some blackwood, which
fixed the problem entirely. I reckon the channel was expanding with
humidity. Thanks again.

I've had this happen a couple of times with my Olwell boxwood flute. They've advised using fine sandpaper in the keyway, doing a couple of strokes on each side, then trying the key again. Repeat till it moves freely. You want to go slowly so that the key can go up and down but not left and right.