Flame polishing is frequently used in acrylic plastic fabrication because of its high speed compared to abrasive methods.
In this application, an oxyhydrogen torch is typically used, one reason being that the flame chemistry is unlikely to contaminate the plastic.
Various machines and torches/gas burners are used in the flame polishing process.
Depending on the heating requirements for an intended application, different kinds of gases are used including but not limited to: natural gas, propane and oxygen, oxygen and hydrogen.
[1] The size, shape, and chemistry of the flames used in fire polishing can vary widely based on the type and shape of the material being polished.