My son with a blue laser burning the garage roof. Actually an alcohol flamethrower. Chris said flamethrowers were more fun than his English assignment. 
“Continue reading” for more construction details. 11 photos and links…

The garage ceiling shot was interesting because the flame tries to rise but can’t so it gives a strange diffuse glow rather than flames. It looks rather unnatural in the photo but was untouched.

An insulin syringe above with 27 G needle spraying methylated spirit (“metho” – 95% ethanol, 5% methanol) through a little propane burner flame. Note that the flame is horizontal.

There are competing forces here to make equal. Firstly a rising force of hot gas. Think candle flame. Secondly a falling force of fluid. If these can be balance by the right mix of gas and liquid and pressure, the beam can be made quite surprisingly straight.

Above: Kerosene burns more completely but is thicker and doesn’t remain horizontal.

The three flames above demonstrate different types of beams that either rise, are horizontal or droop.

This flame above uses a 10 ml syringe with 18 G needle and shows the patch where the unburned metho lands. The 18 G is too large and the stream was drooping.

This is the 10 ml syringe with 18 G needle fixed in the flame and was a lot easier to control. . An insulin delivery pen with a 30 G needle was not particularly impressive however.

Here are two crossed beams (remember Ghost Busters – Never cross the beams).
I used a 27 G scalp vein (butterfly) needle taped onto my little butane torch. The needle was bent into the flame. On its own this gives too much flow with a droopy and yellow flame. I got better results with crimping the end of the needle in pliers. When I overdid this and blocked it I bent it off to break it and this is what gave the best results. No doubt it is constricted in the end. The beam is visibly flatter with less tendency to fall but there are still unburned metho droplets at the end of the ‘beam’.

Demonstrating my prowess with flamethrowers. The pressure is relatively low coming from a 20 ml syringe and long medical extension tubing and held in the other hand that you don’t see.
A little more laser like quality but still rather finicky to keep alight along the whole length. Again, these are the “best of” pictures.

This is the desired effect. Now, how can I solubilise some Strontium in the alcohol to get a red flame like Luke’s light sabre?

Related pages

  Flame diode

Try something else

   Creature gallery

External links

Flamethrower – Wikipedia
See the discussion on Google+

Photo Date: 2005