Back in the 70s when I graduated from fiberglass resin and hardener to West System epoxy, on a number of occasions, when wanting to be sure the epoxy got real hard, I used the "if a little hardener is good, then more hardener is better" approach on a couple projects. I've actually burned skin off my hand by adding too much hardener into a large batch of epoxy, then one minute after mixing going to pick up the container of epoxy - I should say, the smoking container of epoxy! I used to hate when you'd set the container down on your boat deck and the epoxy would melt the container and ooze out all over the place. Well, I have finally learned that there is an optimal ratio of hardener to resin. Perhaps much like there is an optimal amount of soundboard area for a given piano. I still remember the Steinway dealer giving his song-and-dance regarding the big fat tail of my Boston grand - "bigger soundboard area, bigger sound". It didn't occur to me at the time if that were really the case, why don't we see big fat tails on all the Steinways? Terry Farrell > Farrell wrote: > > > Epoxy does not dry, it cures - it undergoes a chemical reaction. David > > Love likely got it right - epoxy can be very sensitive to having the > > exact proportion of resin and hardener correct. When mixing medium and > > large quantities of epoxy, volumetric measurement methods are usually > > sufficient. But with smaller quantities it is best (pretty much > > required) to weigh the proportions on an adequate scale to get the > > proper mix. > > > > > Grin.... reminds me of a fellow tech here in Bergen who wanted to try > epoxy fill of soundboard cracks. He isnt always so clever at listening > to or reading directions. He used West System epoxy to do the job... > but mixed it 50-50 instead of 5 to 1. Restrung and put back together 6 > months later there was still gummy epoxy being pushed out and dripping > down.... I am not sure whether or not he ever got around to redoing the > job... he was a bit depressed about the whole thing... hehe.. > > Cheers > RicB > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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