[pianotech] Bridge cap epoxy

[Ron Nossaman]

On 11/29/2011 8:03 PM, John Ross wrote:
> I am glad you told me about the heat weakening the epoxy, I hadn't heard
> that before.
> In fact I have never heated it in the past, but thought I had seen that
> recommended on the list in the past.

I don't see any point in making it more complicated than necessary. 
Heating it won't detrimentally affect it's use as bedding for bridge 
pins, and it isn't necessary anyway if the epoxy is put in the holes 
before the pins are driven in, rather than used as a top dressing. 
Regular old West System 105 resin and 206 hardener works very well. I 
mix what looks like about what I'll need for a bridge set and keep it in 
the refrigerator, filling a syringe at a time, applying it to the bridge 
holes, and driving the pins before going back to the fridge for another 
syringe full. This keeps the mix from reaching the critical temperature 
and kicking off before I'm finished, and the cold epoxy warms to room 
temperature quickly and soaks into the hole before I can get the section 
epoxied and start putting the pins in. If you're top dressing and need 
something thin, use CA.
Ron N