I have used both the Flexcoat and LS Supreme epoxies and found them to be ok although problematic at times (probably me). Recently I have used a newcomer to the epoxy market, its called Threadmaster (currently being used by R.B. Meiser, CF Burkheimer, and others). The stuff is excellent, good flow and bubble release.about 30-40 min pot life (work time) 2 hr setup. Don't know if I can mention the vendor(not a sponsor) but if you PM or email I can hook you up.
Be careful flaming the finish it's a finesse technique, easy to smoke the epoxy & thread. Warm the bottles in hot water as discussed. You can breathe on the wraps to pop any stubborn bubbles.