I was going to post a candle wax rocket fuel idea but it looks like Nasa has beaten me to the punch again. [link] It dawned on me that it would be possible to use the same technique as the accelerant in a home-made cannon or firearm for when sulfur salt peter, and charcoal are hard to come-by. Once a projectile has been loaded into the chamber a lit candle is then inserted into an open hollow in the rear of the cannon to partially liquefy. A sealed canister of water is then inserted to be held suspended above the lit candle and the open hollow sealed to contain the blast. Pulling the trigger releases the water to vaporize the candle wax creating an explosion comparable to black powder.
-- 2 fries shy of a happy meal, Sep 19 2011

Light'em up! http://science.nasa...28jan_envirorocket/
[2 fries shy of a happy meal, Sep 19 2011]

Ooh, I even found a slow-mo video. http://www.youtube....IMQ&feature=related
[2 fries shy of a happy meal, Sep 19 2011]

Oops. Dinner and drinks with friends last night, halfbaking before bed, and lack of spell check.
Bad combination. Thanks, fixed.

I didn't mean a steam cannon [FT]. The water causes melted candle wax to... what's the word, aerosolize I think, and creates an exothermic reaction. [link] 2
-- 2 fries shy of a happy meal, Sep 19 2011


I understand the first link well enough: LOx + heavy paraffins = boom.

But the second is mistifying.
-- FlyingToaster, Sep 19 2011


<Insert generic "You have totally failed to grasp even the basic principles and physical chemistry of propellants and gas-expansion projectile weapons" rant here>

<Wanders off, muttering>
-- 8th of 7, Sep 19 2011


Erm, I'd say the hot melted wax makes the water vaporize instantly, which splatters the wax out in little bits, which then burn in the air. There's no chemical reaction between wax and water, and it's the water that is expanding. The hot wax just supplies the heat to the water, and as splatters, burns a lot faster than it was going to.
-- baconbrain, Sep 19 2011


Sorry Mr. [of 7]. I will endeavor to grasp harder. If the melted wax contained an oxidizer would it work?
See, I thought it went more along the lines of the old, light an extinguished candle from its smoke, trick. and that the wax smoke itself is flamable. The water droplet sinks and expands sending out a volley of wax droplets which each trail a thin stream of wax vapour starting a chain reaction.

As long as there is enough oxygen to combust the entire wax content then why would this not push a projectile?
-- 2 fries shy of a happy meal, Sep 19 2011


My current hybrid road bike is a cannondale.
-- rcarty, Sep 20 2011


Does it explode?
-- Alterother, Sep 20 2011


Depends on if it is made of titanium or not.
-- RayfordSteele, Sep 20 2011


what Mr. [ meal] said
-- pertinax, Sep 22 2011


Titanium can be made to explode.
-- Alterother, Sep 22 2011


Tell me what cannot be made to explode?
-- pocmloc, Sep 22 2011


// Tell me what cannot be made to explode? //

Plenty of things. By 'made to explode' I mean that the substance itself can actually have combustible or explosive properties. I apologize for my ambiguous prose.
-- Alterother, Sep 22 2011


I'm not confident that this would propel the projectile forward. Remember that demonstration where you light a candle inside a flask, and then stick a peeled egg on top. The candle soon goes out due to asphyxiation, and the egg gets sucked in due to decreased air pressure inside the flask. Though I don't actually know if the decrease in P,V is due to decreased n from the combustion, or decreased T as the candle-heated air in the flask cools. (PV = nRT)
-- notexactly, Nov 26 2015



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