Originally Posted by Av8torTom
Hi, I'm fabricating a plenum for my 9A.
Can I use West System 205 resin, or do I need to go with a higher temp rating resin?
West 105/206 has a relatively low Tg (glass transition temperature), the point at which the solid resin starts acting like rubber. Doesn't mean you can't use it. Just don't expect the part to be stiff at elevated temperature. Not all parts need to be real stiff.
Alternatives? Resin Services HTR-212/386-99 (available from Spruce) lists a very high Tg, too high really, and the person who responds to email avoids specific questions. I've built some parts with it, but I'm not buying any more.
Steve Smith has suggested MGS 285/287 as a reliable choice with a decent Tg, and they publish good info: https://www.aircraftspruce.com/catal...s/mgsresin.php