Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi Brent, It is costly but indoors I use Everclear or Graves. They are both 190 proof grain alcohol. It burns quite clean and never irritates your eyes. 

As for overheating, these burners can all benefit by have a small diameter copper or brass tube letting fumes exit outside of the firebox. Some of the burners come with this. Even when they are so equipped I add a piece of silicon tubing to move the exit 7-10 inches from the burner vessel. 

When they get hot in a firebox the contained heat makes what's in the tank hotter and it pushes out far more alcohol vapor than what is required.

You can also try covering half the mushroom vaporizing burner with aluminum foil.

Gil