Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Additional Notes on the Use of PTFE Powder in Pianos

Here are additional notes on the use of PTFE powder per an earlier thread that I'm not going to necro just to point these out:

In that thread, the use of PTFE power sprinkled in the key bed under the action to make it slide more smoothly when using the soft pedal was mentioned.

PTFE powder can also be applied to the hammer jacks and knuckles with a fine, flat paintbrush to make them work more smoothly, which some might find more playable.

Earlier the fact PTFE is among the slickest solid materials there are was also mentioned. What wasn't mentioned was that, to a point, the more friction that pure, undyed PTFE undergoes, the slicker it gets over time. This is why gamers use it for mouse feet on their gaming mice. When new, these feet have a dull, matte appearance; however, as the mice are "played in" the PTFE feet develop at first a sheen and then an outright shine. The mice, to a point, also move faster and with much less force after each day of use.

The same is true of PTFE powder used as an anti-friction material in pianos.

Given Steinway's experience with using Teflon in their pianos in the past, I would be leery of letting PTFE (aka Teflon) anywhere near my piano.

That was a substitution of the cloth bushings in the action for solid PTFE, resulting in a clicking, wasn’t it? Not powder on sideways, it’s an entirely different ball game.

It wasn’t the chemical itself, rather it’s specific form and application that caused issues.

Exactly. PTFE powder is sold by piano parts and tools suppliers for the purposes described in the OP, among others. It's not like you're putting a solid, kitchen pan Teflon coat on anything. Piano techs with many years of experience have discussed its use with me. The powder is very fine, light, and fluffy, and thus it's obvious when sprinkling/applying it that nothing's ever going to "click."

https://www.howardpianoindustries.com/micro-fine-ptfe-powder/

When playing, it's also obvious that, due to much less friction, the knuckles aren't going to wear as fast. I just had my hammers and shanks replaced with Renner parts, and the old knuckles, which were also Renner and which didn't have PTFE powder applied to them, had flattened and had slick "burn marks" on them, for lack of a better term, from all the friction.

Also much easier to control playing now.

It may be perfectly fine and technician-approved, but I still personally would be leery of PTFE if there were another approach to a problem. Maybe there are situations where it is desirable or required.

I understand and respect (to an extent) your distrust. But, could I ask that if you're going to advertise and propagate that personal distrust, that you make some attempt to rationalize it? Rather than just saying "I'd be leery of it"... perhaps mention why. Is there a genuine reason we should all share your distrust or it is something unique to your circumstance? That kind of thing.

Micronised PTFE powder applied as a dry lubricant to knuckles or slide-ways in and around the action shares absolutely no similarities with Steinway's foray into solid machined solid Teflon bushings. As I mentioned, it was the specific form and application, not the chemical itself, which is essentially the only similarity between the two cases. Unless I'm missing something...

I did rationalize it. You pointed out that my rationale likely was incorrect.

I was hoping that you might elaborate that rationalization slightly because although I pointed it that I felt it was most likely incorrect, you doubled down say that you "still personally would be leery of PTFE".

Would talc produce the same leeryness? Is it a property of the parent material from which the powder is made?

Here is a tech subforum thread from 2015 on the use of Teflon vs. graphite (I find Olek's comments particularly interesting):

https://forum.pianoworld.com/ubbthreads.php/topics/2471086/teflon_powder_vs_graphite.html

Here is an even older tech subforum thread on lubricating jacks with graphite, where Teflon is also mentioned:

https://forum.pianoworld.com/ubbthreads.php/topics/650973.html

Also, just to emphasize that we're talking about a dry, non-liquid, micronised, powdered form of PTFE. In the interest of completeness, there are the following two threads that mention to dangers of using wet, aerosol-can propelled, liquid-carrier delivered forms of PTFE (labelled as dry lube) which have potential risks. But, even then, the risks result from the carrier liquids themselves interfering with specific materials, not the PTFE in general.

https://forum.pianoworld.com/ubbthreads.php/topics/3453121/keyboard-lubricant.html

https://forum.pianoworld.com/ubbthreads.php/topics/3507943/re-wd40-dry-ptfe-lubricant.html

Why would you want a further rationale from me after you refuted my initial rationale?

If my piano needed a treatment to address undue friction somewhere, I would authorize a recommendation from a piano technician who I trusted to address the issue appropriately. I would not apply a physically unstable substance such as a powder or liquid or aerosol (or anything else for that matter) myself based on something I read on the internet.

I might try a DIY repair on a vintage piano I purchased for $100.

...because, as I said... "you doubled down to say that you 'still personally would be leery of PTFE'" without any additional clarification. I didn't know if you had a valid technical objection or were being deliberately contrarian or whatever.

As it happens. It is a very valid objection you raise. One that I missed myself and thank you for raising--I was thinking purely technically. It maybe isn't a job for the inexperienced amateur on their brand-new Steinway. There can be enough of a danger in removing the action itself.

Sorry we couldn't get there more directly! My brain is hard-focused on problem solving right now, I didn't even think of what is probably the most 'normal' objection. Thanks.

Back on topic.

MrSh4nkly: How's the new hammer wearing-in going? Anything interesting developing in the "in-between" una-corda pedaling?

Oh no, I read it on the Internet; it can't possibly be true. As for relying on piano techs, roll the die. I relied on one highly respected technician in my area (at one time had the work for all pianos at my alma mater) for the purposes of making the action more playable on my prior grand. He took a can of WD-40 out of his bag and went down the line of front rail bushing rods in one fell swoop. Within a month they were squeaking.

Earlier I posted a couple of threads with tech opinions in them. Tech opinions, like all opinions, are like you-know-whats: everybody's got one. Sorry, I'd rather research it myself.

Page 145 of Pianos Inside Out, Mario Igrec, a concert technician and master rebuilder who, during his tenure as piano technician at Louisiana State University, worked for Richard Goode, Jon Kimura Parker, Garrick Ohlsson, and other renowned pianists, and who is an award-winning pianist with a Master of Music degree from SUNY Stony Brook, is a table entitled Lubricants. The first substance listed/discussed is the topic of this thread:


So much for "physically unstable substance such as as powder" concern trolling.

^ To clarify, the table on p. 145 is referenced on pp. 156-157 under Knuckles:

I couldn't be more pleased with the Renner Premium Blue Points. They needed a slight amount of sugar coat voicing with shallow (1mm) needles to take the grit of the tone out a pianissimo (still there for forte, which I love). The control feedback of these hammers is an added bonus. They are already breaking in nicely (full keyboard scales in various keys every day). Will post a recording once they are fully broken in.

^ Will post thoughts on in-between una-corda pedaling later.

Although I've done a little in this vein, and am pleased with the tonal palette so early in the game, I'm waiting to test it in earnest until the hammer grooves are fully formed. On the weekends, I'm pulling the front end of the action onto my lap while ensuring the hammers have cleared the face of the instrument, then inspecting the hammer grooves to ensure they're centered. For any hammer grooves that are forming off-center, it's a simple tweak by loosening the hammer flange Phillips set screw with a slight turn of the flange to the left or right followed by a re-tightening of the set screw. Super easy. All the hammers are then checked again the following weekend.

Once I'm satisfied the hammer alignment is exactly where it needs to be for all 88 notes, the plan is to play them in with even more full-keyboard scales, hard, over a span of weeks to fully form the grooves. Sugar coat voicing will then be applied to the non-groove sections of the hammers. In the meantime, I'm keeping una corda usage to a minimum.

In addition to their unique shape, here's something interesting about Renner Premium Blue Point hammers in general:

There are three layers of felt, not two. There's the dense center felt (blue), a layer of very dense light-beige felt over that, and the usual not-as-dense light-beige felt over that. This may explain the weighty, springy feedback I'm feeling from these hammers. Combined with the PTFE powder on the knuckles, the overall action feels far more playable and controllable than I'm used to. Prior to applying the PTFE powder to the knuckles, the action was not nearly as playable with them being so new. There was a slight resistance to play. Felt like fighting jacks and knuckles, and the hands tired more quickly than usual.