[pianotech] Misconceptions concerning contact cement for use with keytops

[Ron Nossaman]

Chuck Behm wrote:

> (Some seem to have no problem with it, but I've seen enough failures to 
> not want to find out why first hand. Ron N) - Two reasons come to mind 
> Ron. Number one, the top of the keystick must be coated twice. The first 
> coat will largely soak into the wood. The second coat, applied at least 
> 15 minutes later, will provide the bond. If only one coat is applied to 
> the wood, the bond will not be strong enough to prevent failure down the 
> road. Number two, if too much time elapses between coating the surfaces 
> and bonding them together (refer to the bottle, but something along the 
> lines of 2 or more hours) the bond strength will not be strong, if the 
> surfaces indeed bond at all.

Chuck,
I didn't attempt to verify why the failures occurred, and have 
no idea what brand or method the installer used. I have 
stripped off PVCE applied tops and find them as tenacious as 
factory applied ivory or celluloid. I have, incidentally seen 
the results of the "Hey Suzie" affect on original ivory and 
celluloid keytops, and on contact cement applied replacements, 
but never on PVCE installed replacements. I find PVCE 
adequate, quick, easy, and non destructive to the surface when 
(not if) I manage to track it where it's not supposed to go. 
If it's not squeezed clear out of the joint by excessive 
clamping pressure, it does the job for me. If contact cement 
works for you or anyone else, I certainly have no problem with 
that. I'm not arguing with you, just describing the reasons I 
have for using what I do. What I do isn't better than properly 
applied contact installed tops, but it's certainly not worse. 
It's just my preference for the reasons I've given.


>The reason 
> PCV-E wipes off so easily, is because it does not interact with the 
> plastic. That is also the reason keytops thus applied may be removed 
> with "easy to moderate" effort.

Since "easy" was with an over clamped keytop, and since 
"moderate" is undefined compared to a keytop "properly" 
installed with contact cement, you have nothing to base a 
comparison on with a "properly" PVCE installed keytop.


> Again, as I stated before, whatever works for you is what's best. I just 
> hated to see people not try a method because of misinformed opinions. In 
> that I've used contact cement successfully for 35 years, I know that it 
> does work. Chuck Behm

Then you'll be trying a set with PVCE real soon now, right?
Ron N