regluing ivories: Duco v. Duro v. CA

[Susan Kline]

>Patrick wrote:
>Perhaps "a thin coat" is "the ticket." I don't use contact cement, because 
>I've often
>seen it leach into the ivory, leaving it an ugly, mottled gray (smells bad 
>too).
>Perhaps this was because too much was used; I'm not sure.
>Last year I "accused" Steve Brady of advocating contact cement for this 
>repair in his
>repair manual (pp. 56-57). He clarified that he advocated use of "Duco 
>cement." I was
>confusing it with "Duro Contact Cement." He was right, I was wrong.
>I do use CA on occasion, but don't use "thin" -- it will eventually fail. 
>I usually
>use medium viscosity.

"Duco cement" is, I believe, airplane glue. I have reglued too many ivories 
where I find a wad of old airplane glue on the back to think it will work 
well over time.

I have sometimes used 5 minute epoxy, but it's a mess. Since I started 
using CA glue, it has never failed for me, and I have never found that any 
ivory came back off later.

As to Patrick's problems with CA glue, I have a few ideas. First, CA 
requires some atmospheric humidity to set up. If he used it in dry winter 
conditions it might not do well later. Secondly, not all brands are created 
equal. I have had good luck with "Quick Tite" made by Loctite, in a 5 gram 
(.18 oz.) bottle. The cap has a pin in it which helps prevent clogging, and 
I find that I can often use all of the small bottles before the stuff ages 
too much, which is unlikely with the 4 oz. Hot Stuff bottles. I keep a few 
unopened cards of Quick Tite in the car.

Lastly, if you want a good bond, you could use the glue trick, which seems 
to work okay with ivory. I hadn't really thought of using it with keytops, 
but Donnie Byrd had no such shyness in Cuba. She had to put plastic keytops 
on a battered old upright, and had no contact cement, but she did have CA 
glue and yellow glue. She used the two together, a year ago, for the whole 
set, and was told by someone with a chemistry background that they were 
incompatible and would never work. She checked them every day, and they 
were fine. This year she found the piano, and they were still fine. It made 
me laugh with glee to hear that!

The general protocol with hard surfaces is to put the wet glue (yellow or 
white) on one surface and small amounts of the CA, spread out quickly, on 
the other. Given a choice, put the CA on the less absorbent surface. Be 
sure that you get the alignment just right, because bonding will take place 
in seconds. Sometimes you can even feel the heat of the chemical reaction. 
Be sure that you get the white glue off your hands before you use the CA. 
It will stick you to yourself or other things far more sternly if it meets 
the white glue on your hands than just the plain CA would alone. Keep 
acetone in your kit or car, just in case. The tube of gelled acetone is 
handy, but dries out once opened.

I see that Bill Bremmer uses the thick CA with Elmer's, and has good 
results. I don't usually have the thick CA with me, but the gap filling 
properties might be useful for keytops, since the keystick often gets mauled.

Regards,

Susan Kline