All in the name of science...

[Thalassamania]

Wooden waterproof matches will do fine. We had underwater phone booths on Hydrolab and some divers who smoked used to sneak out there for a butt. That's how I understand they lit them.

 

[Gene_Hobbs]

My request is that this be recorded! It sounds perfect for YouTube.

The candle will burn faster at depth (even in air) so make sure it is long enough for quality video.

References from the RRR suggested reading list:

SCREENING OF FLAME-RESISTANT MATERIALS AND COMPARISON OF HELIUM WITH NITROGEN FOR USE IN DIVING ATMOSPHERES. (Fire 1)
Cook, Meierer, and Shields. 1967
RRR ID: 4626

REGION OF NONCOMBUSTION, FLAMMABILITY LIMITS OF HYDROGEN-OXYGEN MIXTURES, FULL SCALE COMBUSTION AND EXTINGUISHING TESTS AND SCREENING OF FLAME-RESISTANT MATERIALS. (Fire 2)
Dorr and Schreiner. 1969
RRR ID: 4628

 

[do it easy]

How about a chemical reaction to light the candle? A little sodium metal, a little water, you know the rest. Maybe some of the more creative chemists can come up with a reaction that would be catalyzed by the pressure- a self lighting candle.

Or maybe a 9-volt battery and some steel wool.

 

[ClayJar]

My request is that this be recorded! It sounds perfect for YouTube.

But of course. What use is such an exercise without posting video? (Hey, maybe it can be the next Diet-Coke-and-Mentos... )

The candle will burn faster at depth (even in air) so make sure it is long enough for quality video.

Duly noted (and expected).

How about a chemical reaction to light the candle? A little sodium metal, a little water, you know the rest.

The rest being the rapid evolution of hydrogen gas, large quantities of heat, and the somewhat inconvenient creation of sodium hydroxide (also known as lye)? I'm not sure I'd even want to create a relatively dilute sodium hydroxide solution out of the water I'm diving. It's just the principle of the thing. :biggrin:

Maybe some of the more creative chemists can come up with a reaction that would be catalyzed by the pressure- a self lighting candle.

I imagine it would be easier to have a small glass ampule with a certain size gas pocket inside. At a certain pressure, the cover slip bursts, releasing one of the reagents. On the other hand, I'm trying to think about hypergolic propellants that *aren't* toxic, and I seem to be coming up rather flat. The sodium metal concept would work as a reaction, but controlling it enough to light a candle seems likely to be rather problematic.

Or maybe a 9-volt battery and some steel wool.

That's basically the model rocket igniter concept, but less refined. I should probably get a pack and give it a whirl.

 

[TSandM]

This is one of the funniest threads I have ever read on Scubaboard.

ClayJar, you join the ranks of my two friends who whipped out their wetnotes to discuss the geology of the wall they were diving, as the geekiest divers known

 

[1_T_Submariner]

Please post a link to the video or some pictures after the party!!! Not sure what model Rocket fuel is but real solid rocket fuel will burn underwater (No suggestion here jsut saying).

 

[Thalassamania]

Please post a link to the video or some pictures after the party!!! Not sure what model Rocket fuel is but real solid rocket fuel will burn underwater (No suggestion here jsut saying).

So (I'm told) will C4.

 

[do it easy]

ClayJar, you join the ranks of my two friends who whipped out their wetnotes to discuss the geology of the wall they were diving, as the geekiest divers known

At this point, I think the birthday cupcake is secondary. It seems as if the point now is to create the biggest, non-lethal underwater fire. If you are successful, you'll be eating burnt-up cupcake crispies to celebrate. If not, I get dibs on your gear. Good luck and go big!

 

[ClayJar]

At this point, I think the birthday cupcake is secondary. It seems as if the point now is to create the biggest, non-lethal underwater fire. If you are successful, you'll be eating burnt-up cupcake crispies to celebrate. If not, I get dibs on your gear. Good luck and go big!

On the contrary. The MythBusters M.O. would be to go big and throw out the whole purpose, but I'm far too geeky to get distracted by fire and excitement. The pursuit of science and the original goal is far and away enough to pacify me.

(Of course, if the results of the exercise go on to form the basis or inspiration for fire, explosions, or the like, more power to it.)

Anyway, it looks like I might have my usual buddy around to assist in the attempt, so the odds of documented success have now increased significantly. The waterproof wooden match route seems to be the most basic and most likely successful method for candle ignition, but the 9-volt battery and model rocket igniter route has a particular attraction, so I may give that a whirl, too. As for adequate gas supply to keep the cupcake, candle, and all dry on the way down, I have a spare utility reg and an extra pony bottle, so I don't see that being a problem even in the most complex setup.

I need to make a final determination of what container I'm intending to use for the attempt. Once that's decided, I can work out the ballast situation. Some way of mounting a cupcake holder inside the container would probably help significantly with task-loading (I only have so many hands, after all).

As for singing "Happy Birthday" or some analogue thereof, the two options that seem most likely are the basic "hum/mumble through your reg" and the old standby: holding up cue cards like Wile E. Coyote. The latter has a certain charm, but actually having to come up with real words ahead of time might be a bit much to ask. :biggrin:

ClayJar, you join the ranks of my two friends who whipped out their wetnotes to discuss the geology of the wall they were diving, as the geekiest divers known

Is it significant to my geekiness quotient that the first thing I thought of after reading that was, "What about the wall was geologically interesting?" (My second thought was, "J. would probably enjoy that discussion, since she really liked her several geology courses in college. I mean, hey, she even did two semesters of a geology *lab* course.")

(By the way, do you remember anything about the wall?)

 

[sberanek]

Or you could get an ice-cream cake. Freeze it down as low as possible (try to avoid liquid nitrogen because the cake might shatter when entering the water), drill a hole in it the size of a magnesium flare, light the flare on the surface, stick it in the drill hole, and descend. Or you could bring the wet bell down, light the flare in there (more for safety on this one), stick it in the drill hole, and fun ensues.

The ice cream cake, frozen solide, would probablly hold up much better in a wet environment if you wanted to avoid having to have a dry enclosure for the cake.

--Shannon