Soundboard Clamping for Downbearing

[Ron Nossaman]

>Phenol formaldehyde with various extenders and fillers is common. Heat
>setting, it kicks over at about 180º - 190º F. Cures very brittle & cleans
>up easily. No creep. Very poor gap filler though this can be improved with
>various fillers. Long open life as long as it is not hot.
>
>Del

And quick cycle time in a heated press, I presume. There have been periods 
where loose ribs in new pianos on the showroom floor wasn't uncommon. Is 
this typically an application, curing, or glue formulation problem?

Ron N