#5 Hybrid rocket failure GOX and paraffin

first run of our 2; homemade hybrid rocket motor, fueled by paraffin wax and gaseous oxygen. leaked a LOT, built next to no pressure. set fire to the oxygen regulator. wouldnt exactly call it a success at this point.

** after taking the nozzle out to reload the chamber we quickly realised that the bright yellow drippings you see coming out from below the nozzle starting around 1:06 was not wax as we had previously though, but molten steel. some nozzle repairs are in order before the next test...

Category:

Science & Technology

Tags:

• hybrid
• rocket
• motor
• engine
• paraffin
• oxygen
• GOx
• fire
• failure
• explosion

[kludge000]

also remember to allow for expansion due to heat...

[JonProce]

@kludge000

Excellent point!

[prometheustwin1970]

Nice video. Chemically paraffin is a good hybrid fuel (lots of carbon), but structurally it melts too completely(at low temps) for that use. I'd recommend something less likely to liquify so quickly, like acrylic, polyurethane, polyethylene, even tar.

[JonProce]

@prometheustwin1970

Yup, I hear roofing tar is an excellent hybrid fuel.

[punkefke]

don't get me wrong, but you guys should be ashamed of yourself. hybrids are seriously dangerous stuff if misused. the setup is worthless (on grass?), motor ignited by hand, no proper seals...... think before you act or you will get hurt big time

[JonProce]

@punkefke

I would agree that a "Don't try this at home" label should probably be applied to most of these early tests, but we're safe and healthy, and now our foolishness is entertaining thousands!

[johnmresler]

I've seen a lot of moronic things in the world of rocketry and I've even done some but I've never seen something as idiotic as a guy trying to blow out a fire near an oxygen tank. God smiled on you two idiots this day. :)

[furburger27]

@JonProce I have been working on a similar rocket for a while I was getting up to 25 Lbs of thrust ou of a rocket about the size of a roll of quarters BUT HEED MY WARNING i tried to run one of these off of a remote tank (hopeing for some day launching a self contained rocket) and the tank exploded about a foot from my chest and caused serious liver and organ damage and brusing I ALMOST DIED!!! so be careful oxy is pretty safe but added to a catylist its scary!

[JonProce]

@NotYourStandardIdiot

The bottle itself was well shielded by the wheel barrow, and with the valve fully open there was no danger even if it had heated up at all. Perhaps we could have run into some metallurgical issues with the metal losing its heat treatment, but again, it was not exposed to the flame.

[xshoreLS1]

@NotYourStandardIdiot I know the dangers of high pressure oxygen, I think, but in this case, could it have really been a BLEVE? there was no boiling liquid, only high pressure gaseous oxygen. Also, assuming the gas tank was heated 100 degrees celcius, what would the corresponding raise in pressure be? I didn't think it would be much due to the gas equation. Was very dangerous what happened but I think you categorised it wrongly.

[JonProce]

@johnmresler

I appreciate your feedback! Thanks for watching :)

[JonProce]

@RICKYRASPER

Yup! You're right. There were about 15 tests following this one, you'll find things got a lot better!