Ivory keytops

[Barrie Heaton]

Hi, Jeffrey

That's a very valid point,  regarding expansion and contraction of the
two oposing matterials, expecially as both matterials are poorous.  I
would definitely say of all the bad key repairs I've come across most of
them have been with animal glue .  I am personally still sceptical
regarding the failioure of CA glue I Have been using it for five years
like I pointed out I have only had failiures recently and have put this
down to change of brand (he says this hopefully also not wishing o get
inundated with phone calls from failed ivories)  I used to use pva glue
in the work shop.  I would dearly love to get hold of some glue wafers
alas the supply houses haven't stocked hem for donkeys  years in the UK.
I personally have never used glue wafers have only been told of there
benefits and realised this is the proper way to do the job over the
years of trying to make the join between the tail and the top disappear.

 wes probably a reason for the wafer,


> Richard Wagner's Acryli-Key Repair
This is on the go I have made contact and Richard is sorting out the
problems that will arise from shipping chemicals overseas.  I took a key
to my dentist once and we successfully filled a chip in the ivory
however, it was damed expensive and we coudn't quite get the colour to
match so I fave it up as a bad idea purely on the grounds of cost, but
it looks like Richard has pervevered and found a viable alternative.


Take care,

Regards,

Barrie.



In article <961122032047_739101274@emout10.mail.aol.com>,
TunerJeff@aol.com writes
>Dear Barrie,
>
>    Yup, I wonder about the longevity of CA-repairs myself. It seems to be on
>the brittle or frangible side of the adhesive list, doesn't it???
>
>    Further, I question the use of any such 'brittle' or 'hard' glues for
>keytop replacement. We are attempting to get a bond between the wood of the
>keystick (which expands and contracts with temperature or humidity changes)
>and the harder (much less flexible, anyway) ivory keytop. Using CA-Glue or
>standard wood glue creates a rigid glue joint... or at least, it attempts to
>do so. Problem is, the materials are too far apart in characteristics!
>
>    As the wooden keystick 'breathes', in cycle with the ambient conditions,
>it will flex. The ivory (...although not TOTALLY rigid) won't expand and
>contract as much. Trapped in-between is the glue... doing it's best to keep
>the two together. If one uses a rigid glue, it  WILL fail someday. Won't it?
>Unless conditions around that piano are amazingly stable, that bond gets
>flexed a great deal by the vicissitudes of Life! I don't use CA-glue for
>keytops because I'm afraid I'll wake up one cold & rainy morning (...here in
>Oregon) and find my phone ringing off-the-hook as EVERY customer who's keytop
>I used it on calls to tell me the darn thing(s) fell off. Scary.
>
>    As a student, I always wondered why they bothered to use a glue-wafer to
>affix the ivory to the keys. When I asked, I was told that the
>glue-impregnated cloth provided a bit of movement to the glue joint, just a
>bit of 'give' in the bond between the wood and ivory. One respected
>tuner/tech stated that the glue-wafer actually acted as a 'shock-absorber'
>for the impact of the finger. (That might be worth a 'blind-test' at a
>meeting sometime! Might be interesting to know if we could feel the
>difference between the two bonding methods just by simply playing the key.
>Interesting?). Certainly the glue-wafer set-up takes the factory several
>extra steps in production. They could have simply used white pigment in the
>glue and zapped the keys on in two easy motions... but they didn't did they?
>
>    Isn't this why we use contact cements for adhering entire keytop sets?
>Don't we need some flexibility in the equation here???
>
>Just wondering,
>Jeffrey T. Hickey, RPT
>Oregon Coast Piano Services
>TunerJeff @ aol.com
>
>ps-
>    Was caught by the idea of using colored tape in that interface. Mebbe
>that would help add to the longevity too! (I add to mine by not eating jello,
>or whatever it is...)
>;>)
>    Richard Wagner's Acryli-Key Repair is an epoxy that bonds extremely well
>to the ivory key, and it isn't being pulled in two directions by differing
>materials. Ask him about it, Barrie... but I believe he began with a dental
>epoxy! That oughta bond pretty well to an ex-elephant's tusk, don't you
>think???
>jef
>
>
>





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Barrie Heaton                                  |  Be Environmentally Friendly
URL: http://www.airtime.co.uk/forte/piano.htm  |  To Your Neighbour
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