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The problem with any shim is that if there is a crack in the pinblock below the surface, you will potentially make it worse. The benefit of CA is that it won't be adding stress, and actually may reinforce the block.

If you are going to shim a pin then all you need is a slice of rough cardboard. You don't need a complete wrap of cardboard, you don't need to use sandpaper, and certainly don't use metal bushings. All that is needed is a slice of cardboard about 4 or 5 mm wide and put down one side of the hole.

However, as Ryan says, CA has the benefit of not potentially stressing an exisiting crack. And if you are able to apply it with the pin in situ then you avoid the stress and time involved with releasing beckets.

I agree that the metal tuning pin bushing "sleeves" don't work, in my experience. I tried a few some thirty-odd years ago, had no success, and eventually threw the rest out.


I agree with what you say about cardboard, Chris. And I agree that CA really is the way to go. On an old upright, someone had fitted three of the metal sleeves, and the pins were still horribly loose. I took the sleeves out, coated the sides of the holes with CA, waited a little while, put the tuning pins back, and all was well - nice and tight. And notmrally of course you would not need to remove the pins - just carefully apply the CA. Minimum intervention, and as Ryan says, it may actually afford useful reinforcement.

The moral of the metal sleeve bushings experiences is, I guess, that supply houses will stock things because they can sell them, not necessarily because they work!

What the heck with those metal sleeves???? They've been around for decades. They don't work. They never worked. Who invented them?? Why do the supply houses still carry them? Should we start a petition to get them removed from the industry once and for all?? They are pure crap.

There must be some alternate use for them. Maybe you could make a necklace out of them.

Max uses 3 mm in his daily practice corrugated cardboard. This works well if we have a lot of time and we have our desire. Yes, it is tediously to screwing out every lost pin a hole. Then put in a shim and screw a pin back into the hole.
The main requirement for a tuner to feel with your fingers when unscrewing which width of a strip of cardboard need for the hole. If there is significant wear of the wooden hole, then we setting a shim as a pipe. If the wear is insignificant, then it can be limited to the semicircle of the cardboard shima.
"look, yes you will find ..."
good luck

Adam,
The only time I've ever been party to CA treatment was way back in the 90's- when I was working in the rebuilding shop with the man training me... It was just coming into people's heads to use the stuff (new PTG thing I guess at the time). He said, 'Rick, got something we're going to try on this junk spinet over here just to see if it works'... We tried it out- it worked ok for what it was (no miracles that I saw-- again though, this was back when it was first being tried). We never did it again in all the time I worked there, up through end of 2003.

The reasoning that I have for not having used the stuff as a staple go-to fix is pretty simple.
I don't like the idea of contaminating the pinblock with anything, unless it is absolutely needed.
I do see that CA compared to "PinTite" (or the other doping agents) seems to contaminate less of the surrounding pinblock wood . In my mind though, it's all pretty much under the same category- the, 'do it as a LAST resort' (which used to be the mentality).
I personally still use PinTite as my go to in the situation where I have an old piano in its last years of life (which no one is going to repin/restring).

All other instances (barring a cracked pinblock) I operate based on how loose the pins are, and do as I already stated:
Either tapping the pins in, and humidity control of the instrument (room first and foremost; if not able, then a "life-saver" system)...THAT is not a "temporary solution"- that is a long-term fix (done this far too many times to have people telling me it's temporary).
Oversized pins are the next option (again, we are talking a few here and there in this discussion),,, If we were talking here about cracks in the pinblock, then all of this changes of course, as any oversizing would only open the cracks up more.

In any other circumstance but that of cracks, WHY would I contaminate the pinblock with ANYTHING, if in 20 minutes I can tap an/or replace the pin(s) with some oversized?
That IS a permanent fix, when coupled with proper humidity and temperature control...

I don't understand how it came to the point where we've got everyone wanting to throw CA glue into the piano's pinblock all the time!
Whatever. Trying to discuss this is like trying to discuss climate control systems- everyone is sold and set.

Rick,

I too have made otherwise untunable pianos quite serviceable long term, simply by installing a humidity control system (this statement is limited to verticals only, not grands).

The OP was looking for a 'quick fix. I do not necessarily agree with this approach but favor informing the client of the situation, presenting viable options, and letting the client decide how to proceed. I see the usage of CA components as ONE option among several. I have years of experience CAUTIOUSLY testing this stuff and I know what it can and cannot do. And, just like with a tuning hammer, the technique used can make or break the situation (just watch the inexperienced newbie tuner crank a pin back and forth, back and forth, back and forth making a mess out of it, whereas the experienced tuner gets it done and solid in 2 seconds with minimal fuss).

I do not see it as a cure-all, however used intelligently AND WITH CAREFUL PRACTICE it can serve as a life extension at minimal cost. However the cost skyrockets if you make a mistake as this is pretty powerful stuff. So anyone who wants to can move ahead at their own risk.

Scott Kerns and others have already 'been there...done that', know the risks, learned how to harness it's power, and use it wisely and judiciously. I do not support squirting this stuff all over a pinblock thinking that it is going to produce "miraculous" results.

And finally, metal tuning pin bushings are the mark of poor craftsmanship (actually NO craftsmanship), actually a hack job used out of a lack of understanding. I do not, have not, and will not use them. I agree they should not even be available for use. They were "invented" back at a time when the only options available were an oversized pin, or a new pinblock. And if the tuner was so cheap that he/she could not stock oversize pins in the car, this was quicker, cheaper, and lighter. Those days are gone.

Pwg

What is your definition of 'absolute need'?

"Contaminating" is rather an emotion-laden word.

You say "contaminate" I say "reinforce". An old pinblock that is losing its grip is already compromised. Why put more stress on a compromised block by forcing larger pins or a shim in? Driving pins in a slight amount is OK. However in many cases you will also drive the string deeper into the understring felt increasing the friction. I sometimes find pins that are driven in so far the coil is on the plate - which can interfere with the CA getting down into the pin. And sometimes they are still loose!

The CA fix has been around for at least 25 years now and it holds up. It's proven itself as one of the best cost-to-benefit ratios of any repair.

I agree, Ryan. Why contaminate a pinblock with oversize pins, veneer or cardboard shims, etc!

I sometimes use the word "reconstitute" in explaining the process to clients. I say (truthfully) that the Cyanoacrylate liquid has an affinity for the cellulose in the wood, and reconstitutes the wood fibers round the tuning pins.


As Chris pointed out, too, there is no risk to the becket, as can happen with taking a string off, and putting it back on, a tuning pin.


A couple of years back, a client asked me about his inherited large Strohmenger upright. Strohmenger were a good London make. It had not been tuned or played for many years, and he wanted new casters on it so as to be able to pull it out from the wall.

The pitch was substantially low and the tuning pins were un-tunably loose - of the degree that turns the tuning lever back the other way, when you turn it.


I explained the CA process, and the cost of fitting casters, and the fact that the piano still would be worth very little, due to its age and style, even if the CA was successful. He opted to have the work done anyway. The CA has proven spectacularly successful, over successive tunings.

Did I 'contaminate' the pinblock? What was the alternative? The piano was never going to get a new pinblock, nor would one fit new larger tuning pins throughout - a time-consuming and expensive job.

So now his old upright has a 'contaminated' pinblock, sounds good and plays well and is stable at A440, and he loves playing it.

Thank you Ryan, David and Peter! You`ve stated the case very well. I have almost endless stories of pianos I`ve saved because of CA glue. Just this week I saved a couple of old pianos. There was no way the people were going to spend extra money on an expensive fix. They had gotten the pianos for free and there was a reason they got it for free. They didn`t have the money to get anything else! I find it very rewarding to make these old pianos usable again at a low cost.

I consider the proper use of CA glue for loose tuning pins a solid repair, not a contamination. It's also a huge time saver for me, and a huge money saver for the client. I have had a 100% success rate using CA glue. Repinning or tapping pins are no longer options I consider.

I remember saying to customers 15 to 20 years ago that CA was a last resort, next option was the dump or thousands of dollars. I really did not want to commit.

Then I naturally found out the stuff really works well, years after the treatment.

Now I say to my customers that CA can save their piano, and I say it with full confidence. And it does.

I won't recommend it when I don't think it will work, I tell the customer that their piano is shot... without a few thousand dollars.

Pin blocks that have had CA treatment years ago can still be redrilled for oversized pins. The CA helps, the drill bit goes in like new wood.

Can't do that with a pin block that was "contaminated" with pin-tite. Pin-tite WILL ruin and contaminate a pin block. Can't drill, drill bit feels like it is in jello.

What I have found is that CA will work fine on a pin block that was treated with Pin-tite in the past. So good news for a second chance at a last resort.

Just my experience.

What?
https://en.wikipedia.org/wiki/Cyanoacrylate
You are not right, David. This glue any has no affinity with a wood materials. CA connects the fibers of the tree, partially destroying it's and does not increase it's there. Chemical reaction as a result of bonding is the formation of microparticles of crystals
  liquid glass between wooden fibre . A pin glued to a wooden bush hole factly there in result it's operation.

Jean, these remarks from you as a pinblock expert, are very interesting and useful. I had also read elsewhere that CA will work on previously pin-tite doped pinblocks, so it's interesting to have this confirmed by your goodself as an expert!


I've also found CA to work on pianos whose pinblocks had been sprayed with WD40 by a 'tuner' in my area (who is now deceased).

Eric, yes, same here.

I have used CA glue since I started my business six years ago....don't know what I'd do with out it..

Although I support the use of CA in helping loose pins it may be more appropriate to shim when:

1. There are only one or two loose pins in an upright and no tilter is handy. This also assumes that the looseness is due to wear and not because of a "crack". I happen to think that most loose pins are not due to a horrible big crack that will widen under extra stress.

2. When pins are jumpy and the type that let go suddenly. I have found that CA does not help much. Coating chalk on the pins can also help in this circumstance.

3. Some poor quality modern pianos that go bad on random pins. On two occasions CA treatment did not work but shimming did. I suspect bad drilling had occurred.