Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Can 70% Isopropyl Alcohol Re-expand Bushing Felts?

Or is that just a nasty internet rumor?

Sounds like an interesting PianoBusters experiment to me; perhaps multiple technicians would care to participate and collectively share their findings...

Paul,

Taking your question at face value, here's a counter-question: are you referring to re-expanding a bushing with the pin inserted, or removed, followed by a re-pinning?

(I've tried both, and in my opinion have found pretty definitive answers, but only on a couple of pianos, not hundreds or thousands, so I'm not going to post anything final in the depths of the internet.)

Greetings,
This was once the factory recommendation for tight Steinway flanges. I think they may have changed during the last 20 years of their pinning evolution.

I have used this procedure, and found that it was uncontrollable, usually leaving pinning far too loose and pins suspiciously dis-colored. If done with the pins out of the flanges, as much, or more, work is being done than simply repining them with the next workable size.
Regards,

I presume you are referring to flange bushings and not key bushings. An alcohol and water solution has been used to size bushings to the center pins on new installations. I tried it once on an older set and they became looser, I don't recall if they were too tight or too loose to start. Never did it again. Repin.

....I thought this thread was about re-expanding key bushing felts that have become overly compressed?

Paul, listen to the experts. Do the right thing and repin. In my limited experience, taking the short-cuts for things like this just means you'll have to come back a second time with the correct fix. Why not do it correctly the first time?

Key bushing felts are treated a different way for 'swelling'. Seek advise from your piano technician.

In the case of Paul we might be talking about older pianos with worn bushes.
Paul, if that is the case then the bush is likely to be worn and the pin slightly corroded or with verdigris. I can't see alcohol re-sizing working at all. You really must learn how to re-pin flanges with new-sized pins, and how to re-bush a flange when that is required. It does take a few hours to re-pin a complete set and is well worth investing in the correct tools and the effort to get used to it.

You are correct, A454.7.

Sorry for the confusion, but yes, I have read you can do this
for the flange felts too. It looks like the consensus is that
the proper method in that case is to re-pin. (You mean I've
got to buy yet MORE tools?!? )

But getting back to my original question: I'm referring
to the front rail and balance rail bushing felts, within the keys
themselves.

Specifically on my beater/experimental Richmond upright which
I got for $75. I know I should really take Mark C.'s advice,
and just replace the bushings, which are a bit on the loose side. That's the "proper" thing to do, and something I might do just for the learning experience.

However, I'm 100% positive I will have customers who will
not have the $ to pay me to do this, so I'm looking at
alternative solutions.

And I've read 70% isopropyl can re-expand the bushing felts,
so the keys will be tighter. Myth, or not?

And turning the oval-shaped front rail pin would also work, but
this is extremely controversial (like most everything else, right? HA!):

http://www.pianoworld.com/forum/ubbthreads.php/topics/1539054/Front%20Rail%20Pins.html

I have not used this, but I have used VS Profelt, which seems to work. After the bushings are soaked, you must insert properly sized cauls for the bushings to dry to their correct tightness. You could also do this with steam--same idea. Overly tight bushings can be sized down with properly sized brass cauls that are heated in a soldering iron. An old piano should probably just have their bushings replaced. Depending on the method, it will be faster and less hassle than trying to save old bushings.

I thought you were talking about center pins. I often turn the front rail pins on older pianos. I also bend the balance rail pins back. Also, I have been known to use my voicing tool to size center pins by inserting the needle in the space between the felt and the wood, but in the wood. This squeezes the bushing felt around the pin. Similar to the method of sizing the balance rail hole.

Well, if turning the front rail pins is good enough for
you, that's what I'll do on my old piano.

When you say you bend the balance rail pin back, do you mean
you put a bend in the middle of the pin? So that the pin
will contact "new", un-compressed felt?

So basically you are saying you can needle the wood to expand
it to some degree, right? For both the front and balance holes,
right?

In the Randy Potter Course, in the Repairs chapter, he instructs students about right and wrong practices when repairing a piano.

Turning front rail pins, bending balance rail pins and needeling flanges are all classified as wrong practices.

The right practice is to rebush keys and size them with bushing cauls and rebush and repin flanges, then rim and burnish flange bushings to have the right amount of friction: 4 to 7 swings.

If you really want to become a good technician you have to adopt good practices. It's not harder than making sloppy work that must be redone because it doesn't work properly or, even worst, it damages the piano.

For example bending back the balance pins may prevent the key to be fully depressed in some pianos, if the hole is tight, as it is supposed to be.

In mechanics, as in many other fields, one should find and fix the cause of the problem. If the bushings are worn -> replace the bushings! Why turn or bend the pins? Why squeeze or needle the wood? Why pouring liquids that can cause corrosion in the pins and collect dust and dirty in the bushings?

Paul,

As you have posted so many questions in this forum, I have a question for you:

What kind of piano technician do you want to become?

It ranges from the cheap tech who works for broken pleople with no money to correctly maintain their beated pianos, to the top tech who does quality work on fine pianos.

It is up to you!

Especially needling key stick front and balance mortises, if that was meant. That is just butchering.

I agree with Rafael. Best to do the job properly if you want to project a professional image and have a long lasting repair. Why not do it properly for your client for free for your first attempts and put it down to your learning experience? It will take the best part of a day to complete if you take all the key sticks back, or preferably the whole key frame, home. You may also need to replace the back rail felt, balance and front punchings as well and do a proper regulation.

The key to good regulation starts with well regulated key function in my opinion.

Finally, is it possible for you to post a photo of your problem for future posts?

Paul,

Alcohol/water mix does swell key bushing felt. However, in my experience, if the old felt was already very worn (which it normally is - otherwise you wouldn't be asking the question), then the result of the re-swelling is
... a hard bushing that is
... difficult to size correctly to the pin.

Either it's too tight and tends to jam, hindering repetition at best, or leading to stuck keys at worst. Or the moment it's slightly loose, it leads to knocking. And if you do finally manage to size it correctly, it has none of that wonderful resiliency of fresh felt/cloth. Yes, the keyboard feels tighter, but also "harder".

Thus my limited but first-hand experience on my own project clunker. I'm not going to recommend the procedure to anyone! (Least of all charge money for it.) Rather, I'm going to use my clunker to practise re-bushing, to get good and efficient at it.

Well, ideally, I would be the tech for whatever the
customer can afford!

If you re-read the 4 year old thread:

http://www.pianoworld.com/forum/ubbthreads.php/topics/1539054/4.html


You'll see there were people who disagreed with you
then, and people who disagree with you now, one of whom
is a RPT.

I appreciate your passion for doing things "correctly."

But passion doesn't sway me. Only real-world, economically viable solutions that work, can do that.

I'm gonna end up trying all the techniques, at least once...

Sorry. Thought my opinion may be appreciated but I see I was wrong.

That said, I am entitled to my opinion and I don't deserve to be treated as a Nazi for expressing it. I am notifying moderators.

Paul, you are very rude. I will no longer make any comments for you. Goodbye.