I work with Ipe quite a bit, not for bows, but for decks and other building projects. I've never heated it but, would definitely suggest doing so outdoors. The dust can be quite harmful so I'm sure the vapors let off during heating would be even more so. Also, I've been told that a few different very similar exotics are sold as "Ipe". Possibly this is why some pieces are bendable and others are not? Just a thought.