Pianotech

Decided to add a following comment based on a question asked by Nick Gravange, "Would I do this approach again?" I was vague in my original answer to him. I won't be vague now. No, I would not use this approach again.

Follow-up:
Went back to this piano today for a courtesy visit to check on the tuning stability from applying the CA thin underneath and the topside. It is definitely holding and customer is satisfied. Hooray!

David, Glad to hear you have had some successes flipping the piano. In this instance it just wasn't enough.

I have found this procedure of flipping the piano to be effective with most pianos, and I always recommend a Damp Chaser "Chaser" with the job if the piano is worth it. (I would much rather replace the block, but some Eskimos insist on buying Ice because it is cheap, and that's what they insist that they need. Ironically, hour for hour, we make much more for the "treatment" than for a full rebuild. I do warn that the procedure may not work, and if it does work it is only temporary)
A comment was made that perhaps the glue expands the wood fibers.... I asked that very question a few years ago to the Earl of Adhesives, the Sultan of Sticky, Mr. Ed Dryberg himslef, and he told me that it does not expand the wood fibers. Im figuring he would know.
BTW, I use 1-800 Glue All (Ed Dryburg's ) glue, because he has a good turn around. His stock is always fresh... I have had bad experiences purchasing from a not-so-busy Hobby Store.
Happy Holidays!
Be sure to stick around!
Dave

Thank you for sharing some excellent viewpoints on this process, Susan.
I should clarify the fact that I did do a second application in the weakest areas, that being the tenor and bass sections. Even with that, it wasn't until I did the CA thin treatment topside that synched the deal.

Update: The type of CA bottle shown in the video is no longer the style supplied by Stewart-MacDonald.The type of applicator tip, however, remains the same.

Hi, Keith
I feel that almost everything we say about CA glue at this time is more or less theoretical. Maybe at some point people will do some formal experiments, on pinblocks especially before taking them out to replace them. Then they could saw into the old ones and look under magnification to see where the CA glue really went, how much was coating the tuning pin, and so forth. If they wanted to gild the lily they might even try adding a pigment to the CA to be able to trace it more easily.
If different techniques and amounts of CA were used on different sections of an old pinblock, we might have a better chance to evaluate the effectiveness of different treatments.
So, just taking a flying leap into the unknown, I will share some ideas about CA which I've had. It's such a weird glue. Nothing else acts the same way, as I found out when I first started using it. For instance, it can be a gap filler, but only if it can find no other escape from a confined space, and it's a good at Houdini at getting out of tight places.
What might account for your disappointment after the first laborious, organized, procedure with the overturned grand?
Maybe -- CA doesn't work well in puddles. The inner part of a puddle doesn't contact the moisture in the air, so it doesn't set well. Of course, eventually it would wick in, and in Oklahoma the pinblock would carry enough moisture to set it up ... so, a second maybe:
Perhaps the problem with the first application was just that -- it was a FIRST application. CA has a genius for moving through tight places. It wicks along nearly closed cracks at lightning speed. Just a drop or two can go a long way in a hurry! In fact, I've read one instruction for gluing a joint with CA glue. It recommended clamping the parts together first (!), and _then_ adding the glue!
Thinking about times when I've applied CA to individual loose tuning pins, I've sometimes noted that a second application works much better than the first one. Thinking about why this might be, I theorize that when a pinblock has cracks and is delaminating, the first few drops of CA glue chase down all the tight junctions between layers and between the sides of cracks. It wicks away from the tuning pin, which almost by definition has egged out its hole, and therefore has a gap around at least one side of it. So, the pin remains loose, because the immediate tuning pin area has been starved of glue.
But think about the SECOND application: the first application wicked down all the immediately adjacent cracks and delaminated layers, and then it set up. So, it has sealed the area and the second application has to stay in the hole, in contact with the tuning pin. The second application, then, would reline the hole.
Of course, we won't know if this is happening till someone tries it and then saws apart the pinblock, hopefully with some of the pins still in it. One could check the pins to see if the CA is stuck in the grooves, and one could shine a bright light into the holes to see if they were "lined."
Just a few ideas ... I love CA, though I doubt I'd ever use that much. Good for you, arranging good ventilation!
I treat only the loose pins. I think one of the benefits of CA is that it is so effective and quick to apply that one doesn't NEED to treat every blinking tuning pin! I don't like tedium unless it's truly necessary.
Best,
Susan Kline

Had some further thoughts as to the validity of this process, in and of itself.
Applying from underneath should have been totally adequate to cause an increase in friction. There was no restriction for it to flow into the tuning pin area. However, it wasn't adequate at all. It wasn't 'til I applied CA thin topside at the tuning pin wood plate bushings, that the pins that weren't holding, finally did to a greater degree.
My take is this: The CA thin didn't really go into the pinblock to give greater friction. It was the actual wood plate bushing that caused a greater friction by the application of the CA thin. That's my deduction for now.