glue for hammers

[John Delacour]

At 22:49 -0600 16/1/08, Ron Nossaman wrote:

>My standard is currently still the hot hide. I'm certainly willing 
>to be spoiled, but haven't run into any compelling reason to change 
>- yet.

Me neither, and I'm not even willing to be spoiled!  That's the way 
my hammers end up looking too, with a nice neat o-ring for a collar.

At 19:03 -0600 16/1/08..

>>As I come to glue each hammer I knurl it so that it will be 
>>sufficiently loose in the bore for about half a minute after the 
>>glue has touched the knurling.
>
>How do you knurl each shank as, or just before, you glue the hammer 
>on? After traveling and spacing the set, are you then removing each 
>shank to knurl, then reinstalling it to hang the hammer?

I'll really have to take pictures of the whole process so you can see 
what I mean, which ought to be possible fairly soon, but for now : I 
think you'll agree that the face of the hammer rail, whether Steinway 
or not, is perfectly level and straight and clean, and that if by 
chance it is not, the conscientious restorer makes sure that it is 
before he starts screwing down flanges to it.  Any need for 
travelling is due, therefore not to a switchback of a rail but to a 
minute misalignment of the centre and the base of the flange due to 
imperfect boring and/or bushing, and this misalignment can be 
corrected using any smooth and level rail...which is what I do.

Having travelled the shanks, I cut them to length with the proper 
angle as necessary.  I bore the hammers on a machine which I will 
show you and do it very carefully, changing the angle for each 
individual hammer, which is very easy on my machine, as you will see. 
The boring takes me about 1/2 hour, which is at least 4 times as long 
as Abel took last time I saw them do it, but unlike them I prefer not 
to have chips of drilled wood getting behind the hammer head and 
changing the angle and making it necessary to waste time using a 
tapered reamer later to correct the error.

I then test the shank in the bore to get a feel for how much knurling 
it will need and knurl it as I described before.  I then rotate the 
end of my shank on the glue stick to get just the right amount of 
glue round the end to give me the sort of ring I like, which seems to 
be the same as the sort you like.  No glue goes on the end of the 
shank.  The shank is then inserted into the hammer-head slowly with a 
twisting action so that the collar forms evenly in a ring.  The 
consistency of the glue must be such that after not many seconds it 
will stay put and not sag.  From this point on I need to work fast 
because the shank, compressed by the knurling, is absorbing moisture 
and beginning to swell, so that the head is becoming tighter by the 
moment.  The assembly is clamped or screwed to the jig rail, aligned 
with the end patterns and twisted vertical (or occasionally not, as 
the maker dictates).

You'll get a clearer idea of what all that means when you see the 
pictures, but you get the general drift.  As to the collar, I have 
always seen it as purely decorative in function but it serves to 
demonstrate that the workman knows his trade and does things 
properly, just as the cut end of the centre pin does slightly less 
visibly.

JD






-- 
______________________________________________________________________
   Delacour Pianos  *  Silo  *  Deverel Farm  *  Milborne St. Andrew
                      Dorset DT11 0HX  *  England
                        Phone:  +44 1202 731031
          Mobile: +44 7801 310 689   *   Fax: +44 870 705 3241 
______________________________________________________________________