Starlite

Starlite
en.wikipedia.org

> Mr Ward came to my lab about a year before his death needing help to turn what was essentially a party trick into a useable & commercialy viable product. The problem he had was although the powder component did exactly as it said on the tin, he had found no way of applying a lasting coating. All he really has was some powder mixed with PVA glue, the problem being that although you could apply it to certain objects it's longevity was no more than 2 weeks. While testing we discovered that a sample he'd kept for almost 10 years could be destroyed in a matter of minutes under a methylacetylene-propadiene propane blowtorch. Unfortunately after many samples & tests we where unable to find a effective application method & we parted company on good terms. Sadly this is the true reason why Mr Ward was never able to sell or bring his incomplete product to market.

It looks like starlite while able to withstand more extreme temperatures, also ablates at relatively normal temperatures. From my quick research, this looks like, this is responsible for its longevity issues.

EDIT: relatively normal temperature meaning a blowtorch vs. a rocket nozzle or re-entry heatshield