Bridge + Protek CLP = bad?

[Nathan Monteleone]

Don't worry, it's my own piano that I bought cheap so no foul if I mess it up :)

I was experimenting with lubricating the string contacts with the bridge pins and spilled some Protek CLP on the bridge itself -- apparently I am not quite dexterous enough with a hypo oiler to do it that way. Most of the piano I did with a soaked felt wedge which went much better, but I was trying to figure out how to get to the bridge pins in the tenor.

My question is threefold:
1. What kind of problems is this likely to cause?
2. Is there anything I can/should do to clean it up?
3. If any of you do lubricate string bearings, how do you deal with the overstrung section? I have heard of holding the felt wedge with long tweezers but I was also worried about getting CLP on the wound strings (maybe this is less of a problem?).

[Ron Nossaman]

On 5/27/2013 3:17 PM, Nathan Monteleone wrote:
> Don't worry, it's my own piano that I bought cheap so no foul if I
> mess it up :)
>
> I was experimenting with lubricating the string contacts with the
> bridge pins and spilled some Protek CLP on the bridge itself --
> apparently I am not quite dexterous enough with a hypo oiler to do it
> that way. Most of the piano I did with a soaked felt wedge which
> went much better, but I was trying to figure out how to get to the
> bridge pins in the tenor.
>
> My question is threefold: 1. What kind of problems is this likely to
> cause?

CLP on the bridge? Probably none. About the same as the benefit.

> 2. Is there anything I can/should do to clean it up?

Sure, take the strings off. Really, if it was going to do damage, which
it most likely isn't, it's already done.

> 3. If any
> of you do lubricate string bearings, how do you deal with the
> overstrung section?

CLP is helpful in the front scale, on the counter bearing bars and
understring cloth in the agraffe section. I don't see any point in
lubricating bridges.

> I have heard of holding the felt wedge with long
> tweezers but I was also worried about getting CLP on the wound
> strings (maybe this is less of a problem?).

Specifically, I can't tell you what it'll do to wrapped strings, but
generally, the less a wrapped string is contaminated with ANYTHING, the
better. Look on the bright side, you might produce an excuse to take the
strings off to get to the bridge, needing to replace them anyway.

What is the intent in lubricating bridges anyway?
Ron N

[Nathan Monteleone]

My hope in general was to make the piano easier to tune. Some of the strings seemed more sensitive to small movements in the tuning pin than others. I originally set out to follow the instructions for lubricating string bearings in Pianos Inside Out by Mario Igrec. He specifically warned NOT to get the stuff on the bridge itself, which is why I figured I had screwed up. Just to be clear, he also said to use a felt wedge; hypo oiler was my (bad) idea.

Anyway Pianos Inside Out said to lube the bridge pin bearings as well as the front scale. I think this is intended to improve stability by preventing the string from getting hung up there instead of rendering, only to let go later. The book doesn't say why, maybe Mr. Igrec will chime in :)

[Joseph Garrett]

Nathan,
Below

Joe Garrett, R.P.T.
Captain of the Tool Police
Squares R I
http://gpianoworks.com/


> [Original Message]
> From: Nathan Monteleone <nbm...@gmail.com>
> To: <pian...@googlegroups.com>
> Date: 5/27/2013 1:17:47 PM
> Subject: [ptech] Bridge + Protek CLP = bad?

>
> Don't worry, it's my own piano that I bought cheap so no foul if I mess
it up :)
>
> I was experimenting with lubricating the string contacts with the bridge
pins and spilled some Protek CLP on the bridge itself -- apparently I am
not quite dexterous enough with a hypo oiler to do it that way. Most of
the piano I did with a soaked felt wedge which went much better, but I was
trying to figure out how to get to the bridge pins in the tenor.
>
> My question is threefold:
> 1. What kind of problems is this likely to cause?

Oil makes wood spongy. You should never lubricate the bridge pins imo.

> 2. Is there anything I can/should do to clean it up?

You could try some lacquer thinner, but I doubt it would do any good.

> 3. If any of you do lubricate string bearings, how do you deal with the

overstrung section? I have heard of holding the felt wedge with long

tweezers but I was also worried about getting CLP on the wound strings
(maybe this is less of a problem?).

Lubricating string bearings are Agraffes; Capo Bars, V Bars and
understringing felt, (sometimes). As above, that does not include the
bridges/hitchpins and such.
Now ya know.<G>
Best,
Joe

[Nathan Monteleone]

Again I want to be REALLY clear on this point:

The book's instructions were to carefully apply a small amount of lubricant with a felt wedge to the bearing point between the string and bridge pin and to keep it OFF the bridge.

Please don't confuse my mistakes with what it really said to do :) :)

[Ron Nossaman]

That is quite clear. I just seriously doubt there is any benefit to
lubricating bridge pins. Even lubricated, strings won't immediately
render through until the segment tension differences exceed the friction
of the string against the pins. That typically doesn't happen except
during fairly substantial pitch raises. You can hear the ping as it
happens. Over a period of time, temperature and humidity fluctuations
will keep these friction points moving minutely and segment tensions
will more nearly equalize and stabilize.

I don't know anyone who lubricates bridges, and see no benefit to it.
Ron N

[Nathan Monteleone]

Ok cool. Thanks for the explanation.

[Isaac OLEG]

Yes, I believe it is a little desperate to lube bridge pins (with CLP, or anything) That said iot is not oil if I understand well the product, but PTFE in monomer/solvent. 

Bridge tops can be impregnated with paraffin or coated with graphite or burnished with a pencil lead, but there will always be a part of the tension from the sounding length that will be higher than on the back, , around 6-8% of friction remain blocked at the bridge.

I am unsure super lubed bridge pins would be helpful acoustically, the tiliting of the bridge is fight with countermeasures as bridge curve.

[Isaac OLEG]

Le mardi 28 mai 2013 06:43:14 UTC+2, Isaac OLEG a écrit :

Yes, I believe it is a little desperate to lube bridge pins (with CLP, or anything) That said iot is not oil if I understand well the product, but PTFE in monomer/solvent. 

Bridge tops can be impregnated with paraffin or coated with graphite or burnished with a pencil lead, but there will always be a part of the tension from the sounding length that will be higher than on the back, , around 6-8% of friction remain blocked at the bridge.

I am unsure super lubed bridge pins would be helpful acoustically, the tiliting of the bridge is fight with countermeasures - the natural bridge curve , and the shape of the soundboard.

[David Boyce]

I noticed this too, and was interested, because it's the first time I've seen reference to using Protek CLP at the bridge pin bearings. 

David.

[Ron Nossaman]

On 5/27/2013 11:43 PM, Isaac OLEG wrote:
>
> Bridge tops can be impregnated with paraffin or coated with graphite or
> burnished with a pencil lead, but there will always be a part of the
> tension from the sounding length that will be higher than on the back, ,
> around 6-8% of friction remain blocked at the bridge.

There is very little friction at the bridge top. Nearly all is at the
bridge pins. There is no need for any sort of lubricant on bridge tops.

There's no reason to believe the speaking segment will always be higher
in tension than the back scale. When the piano goes from the damp season
to the dry, the back scale ought to be lower in tension than the
speaking segment. Going from the dry season to damp, the back scale
ought to be higher in tension than the speaking segment. Given a change
in overall string length, the shorter segment will change more in tension.

That 6-8% may be true in immediate measurement, but minor temperature
and humidity changes over time will let the string overcome the friction
and creep across the bridge.

Ron N

[Isaac OLEG]

Hello, Ron

 Thanks for the details;

that would be good news Was a survey done ? (with recordings of the duplex scales pitches for instance ? how was that prooved ?

It is not stated that the friction remain high but that at every pulling anyway and that 6-8% are  pointed the primal source for the S shaped that develop on soundboards. (+- ...)

Then the parsing of the strings and the more or les curved shape of the bridge are told to be considered as elements of the mix allowing to moderate the tilting effect on the bridge.

Anyway at some point the bends in the strings may have hardened and may refrain easily any equilibrium.  I have not a good idea of the number of years, old strings when breaking make sharp points

I suggest that bridge top may be coated  to protect from humidity, hence corrosion of the steel.

The force of the tension differential is said to be as much as 5000N which is enough to tilt the bridge indeed.

All the best.

Isaac

[Isaac OLEG]

What is stated is that the choices are limited, with back lenghts, as longer one will favor better tuning stability but energy loss raise.

Good points on the rounded shape of the bridge that fight the tilting. as a larger parsing of the choirs in treble (that last being not really easy as it may oblige to enlarge the soundboard)

ALl tend to show that once all trade offs have been decided, the window of possibilities is small. As tend to show actual piano design.

[Geoff Sykes]

In Nathan's defense, on page 114 of Igrec's book, there is even a photo showing a felt wedge mute applying lubricant to the bridge pins. I, too, disagree that this is useful. Besides, Protek, or any other liquid lubricant for that matter, is going to seep along strings, pins, etc and eventually wind up in the wood hole in which the pin is seated. Lubricating that pin is definitely NOT a good idea. I also agree that the amount of friction between the string and the bridge pins is deliberately high and the chances of the string actually moving across those pins is probably close to never unless something extreme, as in restringing, is going on. 

[Mario Igrec]

I haven't seen this whole thread, but noticed the exchange below, and I want to say that the photo depicts the moment when the felt wedge just touches the bridge pins. The idea is to apply the lubricant to the string and allow it to minimally transfer to the bridge pin. When you apply Protek Prolube, which is somewhat thicker than the CLP, this way, you can't see it on the strings--the coat is very thin and I don't get a sense that it travels much. I've inspected the bridge and the wood around the pin with a loupe and don't have any indication that the lubricant is getting to the wood. It's not like you are applying multiple drops to the bridge pin.

 

Next time when you have a piano that's more than a quarter tone low, pick a string in the tenor or middle section and make a mark on it with the thinnest marker you can find next to the front bridge pin, then pull the string to pitch and observe where the mark is. If the mark hasn't moved, bend the string gently horizontally away from the bridge pin with a tool like the Davenport Concert String Tool, which I show in Figure 363 on p. 203. Do the same behind the rear bridge pin. You will likely hear a ping, the mark will have moved and the pitch will have dropped. Needless to say, we want this to happen while we are tuning, or after the first pass, so that we can adjust the tension of the speaking length.

 

Perhaps it's the cumulative effect of lubricating the strings at bridge  pins multiple times (a single application may not help sufficiently), but pianos (especially those with oxidized strings and bridge pins) that are treated this way tend to tune more easily and stay in tune better. I haven't observed any increase in false beats. If anyone has using the same method (a thicker  liquid lubricant like Prolube applied just to the bridge pins, not to them directly or over the bridges), I'd like to know.

 

Mario Igrec

www.pianosinsideout.com

---

From: pian...@googlegroups.com [mailto:pian...@googlegroups.com] On Behalf Of Geoff Sykes
Sent: Friday, May 31, 2013 8:00 AM
To: pian...@googlegroups.com
Subject: [ptech] Re: Bridge + Protek CLP = bad?

[Nathan Monteleone]

Thanks for explaining Mario.

Seems like the big complaint most people in thread have is that they say the rear bearings don't move at all during normal tuning (as opposed to a major pitch raise). Do you know of any evidence to the contrary beyond what you already said?

Also my original difficulty was getting past the wound strings to the bridge pins underneath. Do you just drop the tension and move them out of the way?

Thanks again, I have gotten a lot out of your book already.
Nathan

[Isaac OLEG]

Clp does not really travel, it dries, not so fast but it does. The reason I stopped using it on balance pins is that gummy texture it takes after 6 months. So once you begin to treat with such products you may be ready to add more regularely (on action centers I have that strong impression, with temporary better and a curve toward no effect after some time. )
The usual attitude is to avoid beginning with it, if possible (not always)

There is not enough information on the composition of bushing cloth, centers, an CLP, and possibles reactions between them. So I err on the side of caution there and have turned back to old methods.

[Isaac OLEG]

Nathan, the problem of restricted tension is more with major pitch raise than normal tuning.

A setup was (is ?) used at Bechstein to lock the bass bridge with some sort of presses when the piano is bring to pitch. Never seen it, but I had that witnessed.

[Mario Igrec]

Hi Nathan,

I don't know whether they move or not, but I want to give them a chance to
move more readily if they want to move. I agree that for regular tuning the
most important bearings to lubricate are on the side of the tuning pins, not
the bridge.

I don't apply the lubricant to the steel strings under the bass strings. I
wouldn't attempt to go between the bass strings because some lubricant may
end up on the bass string windings and you don't want to risk that. I am
also opportunistic on verticals. If I need to remove the action, I do apply
Prolube at bridge pins, otherwise leave them alone unless I need to raise or
lower the pitch a lot.

Mario

-----Original Message-----
From: pian...@googlegroups.com [mailto:pian...@googlegroups.com] On

[Nathan Monteleone]

Thanks Mario, that clears everything up for me perfectly. Appreciate everyone's feedback too in this thread.