glue for hammers

[John Delacour]

At 20:33 -0800 15/1/08, Jurgen Goering wrote:

>What ever happened to properly fitting hammers to shanks rolled 
>through a good quality knurler?  This compresses the wood and as 
>soon as water touches the shank, it expands to a tight fit in the 
>hammer by itself.   Of course the glue does the main job of holding 
>the two pieces, but the better they fit in the first place, the 
>better the joint will be.

Absolutely!

At 22:42 +0100 24/7/07, John Delacour wrote:

>Provided the hammer bore is correct and the shanks are properly 
>knurled (and I don't mean the factory knurling) it is impossible for 
>the hammer to work loose whatever glue is used. If it is still easy 
>to adjust the angle of the hammer half a minute or so after the glue 
>has been applied, then things are wrong. As the knurled shank 
>re-expands with the moisture from the glue a point is quickly 
>reached where the shank is a compression fit in the hammer-head and 
>so it will remain when everything has set and dried out.  The only 
>way to do hammers is fast.  If you rely on gap-filling properties of 
>glue so that you have an eternity to move the hammer about until the 
>glue sets, then that hammer is at risk of working loose.

I've also been puzzled to read all the agonizing about "glue 
collars".  One of the many virtues of animal glue is that you can 
choose a consistency and temperature suitable for the job in hand; 
you don't use the same consistency for gluing hammer shanks as you 
use for gluing catcher leathers.

Next time I fit new grand hammers I'll take a series of pictures 
showing the process.  Last year I finally built jigs for both upright 
and grand hammer fitting away from the action frame, which makes the 
jobs faster and more ergonomic.

JD