Compression ridges and hide glue.

[John Hartman]

gordon stelter wrote:
> I was wondering today if glue-line creep could be
> considered a significant factor in the ( alleged )
> self-destruction of compression-crowned boards? After
> all, hide glue becomes fairly gelatinous in all but
> very low humidity, so this, combined with the glue
> line stress in CC boards could lead to premature
> failure, and increased compression-ridging.
>      But this may be much less of a  problem with
> modern glue types.
>     Right?
>     Thump


Well Thump,

I think you have this completely backward. Hide glue is the best glue 
for panel edge joints. I had problems with pre made panels in the dark 
past. They were glued with the other alternatives (probably Tightbond) 
and I would have seasonal ridges at the joints. When I made my own 
panels I used hide glue and never had the problem again. I have been 
making my own panels ever since. Piano rebuilding is like baking; for 
the best results make you own pie crust. And the old way with real 
butter taste a lot better the Crisco.

I size the edges with thin hide glue the day before the glue up. Check 
out the photo here:

[link redacted at request of site owner - Jul 25, 2015]

John Hartman RPT

John Hartman Pianos
[link redacted at request of site owner - Jul 25, 2015]
Rebuilding Steinway and Mason & Hamlin
Grand Pianos Since 1979

Piano Technicians Journal
Journal Illustrator/Contributing Editor
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