[pianotech] CA'ing pinblocks in the summer

[Mike Spalding]

  Hi Paul,

Humidity definitely affects how the CA juicing will work out.  High 
humidity swells the block and bushings, allowing less penetration of the 
CA.  On top of that, the humidity will cure the CA more quickly.  
Conversely, in low humidity the bushings and block shrink away from the 
pins, admitting more CA, and the CA will cure more slowly, giving it 
more time to penetrate.  When I first started using CA on pinblocks, I 
scheduled the work for the summer, so that we could have windows open 
for ventilation.  I had a rash of failures that required re-application 
in the winter when things dried out and loosened up.  Now I only do it 
in the winter when the humidity is lowest, and haven't any failures.  
Bushed pins are much more critical - it's harder to get the CA past the 
bushing and into the pinblock, so for sure you want to do those in the 
winter.

Mike Spalding
Fredonia, Wisconsin

On 8/24/2010 6:35 AM, paul bruesch wrote:
> I have an appt this morning to CA a pinblock, but it just occurred to 
> me that perhaps August might not be the best time, or perhaps it IS 
> the best time, due to the humidity in the air. The pinblock will 
> already be as tight as it's going to be, so the CA will have to do 
> less "work", but might it also be less able to wick down the pin 
> deeper into the block for the same reason?
>
> Has anyone observed different effectiveness by doing it in the summer 
> vs in the drier periods of the year?
>
> Thanks,
> Paul Bruesch
> Stillwater, MN