Enlightenment

[Paul]

Susan
My CA glue failures did occur during the winter. Your post explains why. I
am not up to speed on CA, and your insights have been invaluable and
encouraging. I'll try your tips on some shop keys and work out a procedure.
Thanks very much for your help.

Paul Chick
----- Original Message -----
From: Susan Kline <sckline@home.com>
To: <pianotech@ptg.org>
Sent: Tuesday, September 26, 2000 9:19 AM
Subject: Re: Enlightenment


> At 07:19 AM 09/26/2000 -0500, you wrote:
> >Susan
> >I've tried CA for regluing ivory and found the joint to fail most of the
> >time. I take care to clean the ivory and keystick, but usually find that
> >repair has failed. I don't wet either piece with anything in the cleaning
> >process, just scrape the surfaces and wipe off with a clean rag before
> >applying the CA. What am I missing?
> >
> >Paul Chick
>
> Dampness, probably. You see, CA glue wants to bond and polymerize like
> crazy. <grin> The only thing that keeps it liquid is an inhibitor, which
> is an acid, and it's very powerful, because there is only a tiny trace
> of it. It breaks down in contact with water, and it only takes a small
> amount of water, such as we would have in a normally humid Oregon day.
> It's possible that you tried to use it during a Minnesota winter, and
> the air was just too dry.
>
> Try either cleaning the keystick with a damp rag, or scrape it clean,
> but then smear a very thin layer of Elmer's glue on it. Put some dots
> of CA glue on the ivory, spread it into a layer (quickly!) with a
> screwdriver, and put it in place. If you use too much CA glue it will
> squeeze out and get onto your fingers. (Heck, it'll get onto your
> fingers anyway.) At that point, as you press the ivory down you'll
> leave a nice vivid CA fingerprint on the ivory, which you will
> then need to use acetone to remove. (I've tried scraping and 600
> sandpaper: not very effective.) Keep this squeeze-out off the fronts,
> in particular, since they are usually melted by CA glue, and by
> acetone as well.
>
> If you have a decent brand of CA glue (I like Loctite's QuikTite)
> and follow this procedure, it should bond like mad, and I've never
> had one come off again. Give it a try and tell us how it goes.
>
> Put the Elmer's on the keystick because waterbased glues can warp
> ivory and because the CA won't wick into ivory. In general, if
> gluing a hard and a soft surface together, put the CA on the hard
> surface and the Elmer's on the porous one. If the two surfaces are
> both soft (like gluing cloth to cloth) put the Elmer's on both,
> squeeze together to spread it, add a small amount of CA to one
> or the other, and IMMEDIATELY press together again. The Elmer's
> will prevent the CA from soaking in too fast. As soon as the CA
> hits the Elmer's it bonds with great enthusiasm, generating heat
> and a few bubbles. That is, the squeeze-out is clotted and a little
> foamy.
>
> Be sure your fingers are not wet with the Elmer's when handling
> the CA glue. If I use CA glue alone, and stick my fingers together,
> I can pull them apart, just leaving a thin layer of skin behind.
> But one day when I had a trace of white glue on my fingers, the
> CA glued them together so firmly that I had to go to the car to
> get the acetone so that I could dissolve the bond. It took quite
> a bit of acetone and a little struggling, even so, to get the
> stuff to let go.
>
> If using CA and Elmer's to glue on rubber buttons, be sure not to
> use too much, and use great care in cleaning it up. If you smear
> the squeeze-out across a piano case, it'll look terrible and is
> nearly impossible to remove. (Don't ask ...)
>
> Susan
>