For some reason, I didn’t remember until days after fabricating the first plenum that I didn’t use the high-temp epoxy that I bought. I thought about just using it for the additional layers of the first plenum, but decided it wouldn’t be that much more work to just lay up an additional plenum. This epoxy is definitely more brittle than West System epoxy. I’m hoping it toughens up after adding a few more layers and post-curing it at high temperatures.
