<br><font size=2 face="sans-serif">Tom-had to resend without all the attachments</font>
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<br><font size=2 face="sans-serif">Morton Thiokol does not make resin, BUT you are on to something......Morton Thiokol, now called ATK ,filament winds rocket motor casings, and that Shell 8500 is a favorite of filament winder guys. Epoxies typically have extremely long shelf lifes. Some preformulated epoxies do have consituents that may increase the viscosity with age, if not refridgerated. As far as cost goes it is all relative. There are expensive epoxies at about $15 lb. Regular epoxy (bisphenol A) is $3 lb when purchased in a 55 gallon drum and about twice that by the gallon. High temperature resistance usually comes from th echoice of hardener not the epoxy resin. Epoxy resins that can increase temperature (multifunctional) resistance are solids at room temperature-not too pattern guy user friendly. Preformulated epoxy systems cost 5X-10X the raw material-usually from the hardener side. Example-West systems epoxy is a "formulated" hardener , !
that is a blend of several components and the epoxy side is packaged straight from the drum.<br>
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Gray Fowler<br>
Principal Chemical Engineer<br>
Composites Engineering</font>