Tuning slide lubricate or not?

Irish Flute
21

Very interesting Jonathan, thanks for sharing your experiences on the subject.

Since my own experience with the older flutes has been primarily limited to examples that have been mostly well maintained in recent years, or at the least don’t have seized slides, the ones that I have encountered (at least to my memory) had currently lubricated slides, hence my quite possibly erroneous assumption. I can however say, that to my memory, virtually all the examples of vintage flutes I have encountered, where the slide was lubricated, I found the connection between the slide parts too moveable to be what I would consider properly stable for playing and handling. Preferences will no doubt vary some on this, but my limited experience and preference in this area seems to match yours, as I do think a properly fit slide should stay where you put it and shouldn’t be moved from that position by minor jostling during handling and playing.


So, I think it is probably more common than not to see flutes made with slides that are precision-fit to function properly dry.

It’s an interesting idea, and I can think of several reasons not yet mentioned why this might be so, however this thread is already getting long, and my thoughts would provide only speculation, rather than facts.

For such a design it probably made sense to ask that the flute be stored with the slide intact to minimize wear that could conceivably/potentially loosen the fit.
With enough years of hindsight we might reasonably conclude that this degree of caution wasn’t really necessary, but I still think it is a reasonable precaution, especially since we can disassemble at a corked or thread-wrapped joint close by, and replace the wrapping when/if worn.

Could well be, though I imagine there may have been other reasons, but again, I’ll skip adding my speculative thoughts at this time. I can’t help but wonder if someone knowledgeable on these subjects didn’t write about such things back in the day?

Thanks again for sharing your experience and perspective, based on the flutes you’ve worked on, I find it fascinating.

22

Now, we haven’t heard from Gromit in a long time. Any progress or changes to report, Gromit?

23

Now, I had said above:

And suddenly, we now have a test patient. A local flute player just dropped in one of my flutes to get a tenon recorked, and also mentioned the head was hard to move. When I went to examine the slide, the slide came right out of the head! The two slides were bonded, presumably by our old friend, breath condensate. She was not actually moving the slide, she was pulling the head slide in and out of the head where it is corked! Hence it wasn’t that smooth or easy.

The slide coming right out of the head is no big deal in my New Improved Tuning Slide arrangement, where the two sections are held in place with cork lapping. Indeed, it makes separating stuck slides much easier, as you can get unimpeded access. Indeed, I’m tempted to pull it out of the barrel end as well, just so none of the woodwork is involved, just two metal slides and some cork lapping.

But my purpose in raising this now is that it gives us a convenient opportunity to test to see what else might dissolve breath condensate. But I need to test in the “less likely first” order, as we know alcohol will easily remove it.

Should I go:

  1. nothing. Try reinserting the slide, once it’s cooled right down.
  2. warm detergent solution, then test again.
  3. white vinegar, then test again.
  4. hand sanitiser, if we happen to have any! Then test again.
  5. Isopropanol, as I know methylated spirits works. Then test again.
  6. Meths, in the unlikely case nothing above worked! Then test again.

Or would anyone like to suggest another potential solvent, or a different order?

Now, one weakness in the above is by the time I’ve tried sliding it in and out that many times, it might well have abraded itself clean! But let’s see.

And once I have it clean, I’ll review the difference between lubricated and non lubricated. I normally go with cork grease as the readily available lubricant, but if anyone wants to suggest another, I’m willing to try it if I happen to have it!

Now, I can’t put off fixing this lady’s flute for too long as she has a festival coming up, so I’d appreciate quick responses!

24

Whoops! Unexpected deviation from plan proposed above…

While waiting for any responses about the proposed order of testing solvents, I thought I’d at least pull the stuck pair of slides out of the barrel, which requires me to clamp the protruding slides firmly in the lathe chuck while pulling and twisting the woodwork of the barrel to free up the corked barrel slide. In order to protect the slides from crushing, I put a close fitting turned Delrin rod inside, and a Delrin sleeve on the outside.

But as I twisted and pulled the barrel, the slides decided to separate. But maybe that’s a good thing, as it bypasses the “apply lots of heat to separate slides” bit. I worry that applying the lots of heat not only softens the condensate, allowing the slides to separate, but maybe “cooks” it, potentially changing its chemical makeup. And that might mean that a solvent that works on uncooked condensate might not work on cooked condensate, and vice versa. So we are definitely in the “uncooked” area.

So, what do I see? Nothing dramatic. Dramatic might mean lots of corrosion, blatant discolouration, physical damage, etc, etc. Nothing like that.

Which is not surprising. These two slides are sterling silver so unless you’re quaffing nitric acid, there shouldn’t be much that can eat it.

Looking critically at the inner slide and up the outer slide, all I see is something that looks a bit slimey, and is perhaps faintly yellowish? But so faintly yellowish it might be imaginitis. I might learn that when I try to wipe it off.

And the “slimy” look might just be cork grease, applied by me or the owner to make the slide run more nicely. In the slimy surface, I can see the memory of the twisting action I used to pull it apart.

But immediately, I see the need to modify the strategy by inserting a new No 2:

  1. nothing. Try reinserting the slide, once it’s cooled right down.
  2. wipe slides with dry cloth, then test again. Maybe it will just wipe off?
  3. warm detergent solution, then test again.
  4. white vinegar, then test again.
  5. hand sanitiser, if we happen to have any! Then test again.
  6. Isopropanol, as I know methylated spirits works. Then test again.
  7. Meths, in the unlikely case nothing above worked! Then test again.

I can already report that it didn’t fully pass the first test:

  1. nothing. Try reinserting the slide, once it’s cooled right down.
    I’m sure I could push and twist it together, after all, I got it apart, but I could immediately feel too much resistance to make that acceptable. And I didn’t want to imperil further tests.

So, do I go on with tests 2 to 7, or are there any proposed amendments?

25

OK, at this point, I felt I needed to make some progress to make sure my customer has her flute back in plenty good time for her upcoming events. So time to start running through the strategy I set out above.

  1. do nothing. Try reinserting the slide, once it’s cooled right down.
    And as I reported earlier, we didn’t need heat to get it apart, so no cool-down needed. But there was too much resistance to feel good about just pushing it back together.

  2. wipe slides with dry cloth, then test again. Maybe it will just wipe off?
    Did help. The slides did look cleaner, they did work, but were still too tight. Noted some staining remained at the end of the inner slide.

  3. warm detergent solution, then test again.
    Looked a bit better again, but still too stiff. Maybe the slides just need lubrication?

  4. white vinegar, then test again.
    Didn’t seem to do anything. I think vinegar probably only helps with calcium buildup, eg in the windways of recorders and whistles. Or perhaps if Verdigris is noted in brass slides. It has nothing to offer sterling silver, which is what my slides were made of. Makes sense, chemically speaking.

  5. hand sanitiser, if we happen to have any! Then test again.
    Oooh, goupy stuff, isn’t it! I’d rather forgotten the dreadful Covid days. But it made the slides jam. Didn’t expect that. But maybe not all sanitisers are the same?

  6. Isopropanol, as I know methylated spirits works. Then test again.
    Sadly, we didn’t seem to have any. I’d expect it to work at least as well as meths.

  7. Meths, in the unlikely case nothing above worked! Then test again.
    Ah, best so far. But still a bit tight.

So, that brings us to the end of the solvents. And on to the topic of lubrication…

  1. Dab of cork grease onto the outside of the inner slide, rubbed up and down and around, insert slide into outer slide and work around. Great!

  2. Wipe off the cork grease from inside and outside of slides. Too tight.

At this point, I’m starting to worry that perhaps this slide would benefit from a bit more clearance, so it’s not quite so dependent on being clean and well lubricated?

So, I lightly sanded the outside of the inner slide, spinning in the lathe with 400 grit, followed by 600 grit abrasive paper. Then “cut it” on the Tripoli wheel, and polished it up on the buffing wheel. Looked great!

  1. Tried it dry. Ran together OK, but a bit “scritchy” feeling.

  2. Greased it. Really smooth but not loose. Perfect!

So, what have we learned?

  1. That cleanliness and lubrication are different topics. We need to pay attention to both.
  2. That methylated spirits (and probably isopropanol) are the easy go-to solvents. Nothing to lose, everything to gain.
  3. That this supports the notion that the “glue” that’s causing the sticking is breath condensate, rather than dirt, dust, lint, corrosion, etc.
  4. That unless the slide is very loose, lubrication is going to be important. It can be as simple as cork grease.
  5. That maybe it’s risky having slides that are too well fitting. Any little build up of slime, any forgetting to keep them lubricated invites them to stiffen up, and then to jam. Hopefully, the amount of freeing up I’ve gone for is enough. Only time will tell!
26

Polish it after the various liquids but before the grit ? Does buffing do something to the surface that cleaning doesn’t ?

27

I wonder if there would be any gain from making the two metal rings of a tuning slide out of different metals that expand at different rates so that the outer one would get bigger more than the inner one when moderately heated. That might help to unjam them when these problems occur.

28

Hmmm, interesting questions.

Up to now, we’ve been focussed on two main topics, cleaning and lubricating. Solvents and greases.

But at the end there, I introduced a new topic, sanding down a slide I concluded was too tight.

I think we should see that as a rarity. Normally, slides will leave a maker when they seem to be working well. So, as long as they are kept clean and lubricated (solvents and greases), all should be well.

But of course, “seem to be working well” is a value judgement. Sooner or later, a slide that “seemed to be working well” will later be re-evaluated as, “hmm, perhaps left a bit too tight?” As with so many things, such judgements are easier in hindsight.

I’m saying all this, because I think it would be pretty rare that we would need to go beyond cleaning and lubricating to sanding and polishing.

I should mention that this slide is unusual. I think it might have happened at a period of transition, as it is very different from my more recent slides. So didn’t have the benefit of that level of accumulated experience.

But let’s assume you have come across a slide that was stuck, and managed to free it, or a slide that was almost stuck, and you saved it in time.

So you use a good solvent to clean off any sticky slime. And you apply and distribute a lubricant. You’ve done your best with solvents and greases.

But you are still not happy. The slide is not performing well. It’s job is to slide, but perhaps it’s catching and grabbing? Do you, like I did, hit the sandpaper? Or do you, as david_h suggests, try some less aggressive form of cutting and polishing first?

I think in the general case, I’d go with David’s suggestion. Try a mild abrasive, eg Brasso for a brass slide, Silvo for a silver slide, just in case it’s enough to do the trick.

In my case, I’d plead that long experience allows me to take some short cuts. It’s interesting that I just confidently set to, using the two admittedly very fine sanding papers without a second thought. And got away with it! The slide is now working perfectly.

I did do one thing I didn’t mention. Imagine you have two concentric cylinders trying to slide over each other, but not as easily as you’d like. Is it because they are two tight at the left hand end, too tight in the middle, too tight at the right hand end, or are there high points, or all of the above, or what?

So to guide me as to where to take off metal, I took the inner slide and drew lines along it using a marker pen. Maybe 10 parallel lines, spread right around the circumference. Let them dry, then assembled the slide, and rotated and slid it back and forth for a minute or two, and then pulled it out to review.

The wear patterns on the lines were pretty uniform, so I concluded I just needed to “take a bit off” all over. But if say the problem was high points, then the lines there would be obliterated while the rest of the lines would be fine. It’s a good metal worker’s trick to keep in mind.

Now let’s focus on David’s second question: “Does buffing do something to the surface that cleaning doesn’t ?”

Hard to answer confidently, I think. Probably not in the general case. But maybe if something has roughened up the metal’s surface - corrosion, abrasion, whatever - and you feel this might be causing poor sliding, it’s worth a shot to use a mild abrasive to see if that will solve the problem. But I wouldn’t use that before making sure the surfaces are clean and lubricated. You should always try to restore before you try to change.

29

I’m thinking that if whatever was making the slide stick wouldn’t just wipe off then their must be some sort of bond, or maybe chemical reaction (if that’s different a different thing). Does buffing reduce the surface area? Or is it just as rough but at a smaller scale. That might make it take longer to go bad again.

Giving a shine to the E.P.N.S spoons that retain some aesthetic/sentimental value but no E.P. seems, subjectively, to make the washing up easier.

30

Hi folks, there have been a lot of interesting discussions on this topic. I contacted Chris Wilkes (the maker of my flute) and recomended using Molykote 111 a silicon gell. I ordered a tube and it arrived this morning. Once I’ve applied it I’ll post the result, thanks for all the information.

31

Yeah, that looks like a good lubricant for such a location. I use a similar one (HydroSeal?) I use whenever I change the tap washers around the house.

People forget that it’s not just the washers that matter in a tap. Up in the top of the tap there are one or two rubber O-rings and the long threaded shaft that makes the tap open and close slowly. These need cleaning and lubricating as well, but are often overlooked. Make a note to do this next time you change a tap washer! The difference is sometimes dramatic.

Ha ha, and you’re going to love this. I said above “I use a similar one…”. I just went down to get the one I use and found it’s the same one exactly! Must have run out of the other one!

So, just for interest I put some on a slide here that I thought a little bit scritchy and it’s now really lovely. Indeed, better than cork grease, though cork grease remains better than nothing.

This all supports my theory that plumbers and flute makers are essentially in the same business. Making fluids run up and down tubes in a predictable and satisfactory way…

32

Now, Gromit, remember I made a big deal above about a distinction between cleaning and lubricant. I advocated alcohol for cleaning and cork grease for lubrication, but happy to accept Molykote as a better lubricant.

But I can’t imagine that Molykote has significant cleaning properties. I could be wrong!

Or is could be that it’s such a good lubricant that the presence of some hardened breath condensate is not a big deal, this stuff will ride right over it.

So, I’ll be interested to hear if application of the Molykote is enough to alleviate the tightness that bothered you, or if you feel you need to go further. In which case, I would suggest wipe off the Molykote from inside and outside the slides, wipe the slides with an alcohol soaked rag, let dry (won’t take long!), then re-apply the Molykote and try again.

Let us know your thoughts!

33

Thanks Terry, I have yet to take the slides apart but intend to give them a clean with Isopropyl first then apply the Molykote.

34

The temperature In London has increased from 5°C to 13°C overnight, sllde still tight but is easier to move now.

35

Woah, I can remember those temperatures in London!

Now when you say “sllde still tight but is easier to move now” is that just because of the change in temperature, or have you done some of the cleaning and lubing we’ve been talking about?

36

Seems to be due to the change in temperature as I’ve not cleaned or lubricated it yet.

37

Interesting. I guess the space between the slides for the gunge is also getting smaller when the temperatures drop, but would that really be noticeable?

Or is the gunge softening a tiny bit with even a few degrees increase in temperature? I wonder if anyone knows the answer to this question? Trombonists?

Gromit, it would be interesting to do the cleaning of the mating surfaces, let that dry (a minute should do!) and then offer the slides together to see if they now run relatively easily. But if you are tempted to try that, do be prepared to back out quickly if you strike constriction. The last thing we want now if for the slides to grab!

But given you have run this flute for many many years without lubrication, it seems likely that it’s not vital to it.

Assuming it can be operated dry, take note of any sense of scritchiness (the feel of dry metal on dry metal). Does this disappear when lubricated? And do you get a feel that the sliding is more “controlled” than when dry. Smooth, uniform, progressive, rather than snatchy, variable, slightly jerky?

I just tried the slides on the two flutes I lubricated earlier - they still both feel great. It will be interesting to see how long we can go between treatments. I can’t see players tucking a tube of Molykote into their flute cases. Enough I think to leave it in the drawer at home and dab a bit on when the slide starts to feel dry.