This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Thanks Carl. You may well be right about higher temp curing not = affecting the epoxy strength. I read all through the West System web = site and could find no reference to it. They did identify the weakness = caused by solvent thinning the epoxy resin, but apparently heat will not = compromise it. Terry Farrell =20 ----- Original Message -----=20 From: Carl Meyer=20 To: pianotech@ptg.org=20 Sent: Sunday, January 06, 2002 2:15 PM Subject: Re: Epoxy Terry, the specs for max service temp for epoxy vary from 150-400 = degrees F on a typical brochure I have from Hysol. I've never heard = that high temps at curing (under the max working temp) would weaken the = result, but I may be wrong. Most mfg. give a recommendation, but I = think they say room temp cure merely to say that it will indeed cure = without heat. Some won't. I recall years ago I worked for a company that made voice coils for = computer disc drives for IBM. The adhesive used to coat the windings = was a structural adhesive made by MMM. The cure schedule specified by = IBM was 1 hour at 130 F followed by 1 hour at 250 C followed by 1 hour = at 350 C. (that's 842 F). The normally green epoxy turned brown. I = gleefully informed the IBM engineers that the heat was in excess of the = operating temperature specified by MMM. After much gnashing of teeth, = fancy footwork and backtracking IBM changed its specs, and we found it's not too hard to be green. http://www.epotec.com is the website. Epotec301 has a Shore D = hardness of 81 I've just learned that clear coat has a viscosity of approx. 600 for = the resin and about 200 for the hardener. I'm not sure how the mix = relates but it should be about 500 since the mix ratio is 2-1. Happy gluing. Carl Meyer Assoc. PTG Santa Clara, California cmpiano@attbi.com=20 ----- Original Message -----=20 From: Farrell=20 To: pianotech@ptg.org=20 Sent: Sunday, January 06, 2002 8:03 AM Subject: Re: Epoxy Hi Carl. My info is that elevated curing temperatures can tend to = weaken the cured epoxy. It would concern me to heat bridge pins. It may = not be a valid concern as I'm sure the heat is dissipated rather = quickly. I have always found West System to be thin enough to wick into = all birdseye cracks around bridge pins - when the pin are removed. I'm = sure it would be nice to have an even thinner epoxy - although, I wonder = if it would be as convenient to apply - the thicker West System holds a = nice drop on a wire or on the bridge pin base for application! What is = the strength characteristics of the Epotec301? Is it as strong/hard as = West System resin? Do you have a web site for Epotec301? Oh, and BTW: Just sent out an old Fisher upright with a completely = rebuilt action and a VERY nicely leveled set of keys! Terry Farrell =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/f3/3d/9b/ef/attachment.htm ---------------------- multipart/alternative attachment--
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