The Cauldron
Misc. inspirations

Most of my ideas came while lying in bed thinking. Though I'm not going to try to attempt to re-list all the morning-inspirations I've had during this long process, I'm going to keep track of inspirations as they come now.

January 3: Photograph the inner bubble fire

December 29: Diverter for water flow in

December 6: smaller CO2 fire extinguisher
December 6: reducing fuel leaks near the flames
December 6: pumping fuel using water in the Cauldron.
December 6: pumping fuel using water in the Cauldron -- what if major fuel leak?

November 19: Dumping the water

January: Pumping the fuel

January 3: Photograph the inner bubble fire

Problem: Inside the water bubble that comes down from the top bowl, the flames inside can be most spectacular.  I would like to photograph these, but this is a bit difficult...

Solution: My first thought would be to put a camera in a ziploc baggie, but such a thing might melt near the flames...  I am open to suggestions on this one!

December 29: Diverter for water flow in

Problem: The water coming over the top is a bit too fast.  I need to reduce the flow of water in.  I have a 3" ball-valve, but it's a bit more complicated than it might seem, because the elbow for the water in has to fit through the hole in the barrel pedistle.

Solution: I guess I'll have to have two flexible couplings, or one screw-type coupling.  So I'll have to fit the elbow through the hole, then screw or attach a Y with a valve on it, then attach this to the water line in.  Just as long as it can be taken apart for packing and moving.

December 6: smaller CO2 fire extinguisher

Problem: I have a little bit of trouble weilding the 10# CO2 extinguisher, much less the 15# one. I was trying to figure out if there's a way to use those CO2 cartridges used for seltzer dispensers...

Solution: Scott had the idea of using the CO2 bicycle tier emergency pumps! He says there's a number of them on the market, and I should shop around.
Of course, this is no real substitute for my good fire extinguishers, but might make the difference in small cases, like if someone's sleeve were to catch on fire.

December 6: reducing fuel leaks near the flames.

Problem: I have tried to isolate the fuel as much as possible from the flames themselves. The only breaks in the line are at the fuel pump [far away], at the connection to the top bowl [leaks go into the water and burn up], and the needle valve at the fuel tunnel opening. This last connection was what gave me the problem at Burning Man: it is too close to the actual flames for comfort if it were to leak.

Solution: I realized that I don't need the valve so close -- the hope is that I'm adjusting it once and never again anyway... But the clever part is I figured out that I don't need to buy more fuel line; I can swap the short piece [between the top bowl and the needle valve] and the long piece [between the fuel pump and the needle valve.] In fact, the needle valve is bi-directional, so I need only detatch the hose from the top bowl and the fuel pump, and turn the whole thing around!

December 6: pumping fuel using water in the Cauldron.

Problem: Since the Cauldron doesn't need nearly as much fuel as I anticipated [5 gallons lasts a couple hours instead of less than one hour], I'm considering pumping the fuel using water like I did the Ceramic Thing. This way I could put the whole she-bang inside the Cauldron so any leaks would leak into the water and burn up and not create a safety hazard. The problem is, I'll want to keep everything under water as much as possible, and this would probably include the valve!

Solution: I could adjust the water flow in the fuel tank [and thus the fuel flow] by putting the valve inside the inside aluminum flashing and running a long handle to bolt to the rim of the bottom bowl.

December 6: pumping fuel using water in the Cauldron -- what if there was a major fuel leak?

Problem: what if something major happened to the fuel tank under the water? What if all of the fuel leaked out into the water at once? [Note: I doubt this would cause something horrible like a fireball, since the limiting factor is air. But it would probably burn too hot and harm the bottom bowl. I'm not going to try it, though. :) ]

Solution: Keep four wool blankets stitched tightly together to throw over and smother the whole thing. Probably a good idea to have on hand anyway to throw over someone if their clothes were to catch on fire. Then follow with the extinguishers firing through the blanket -- that way the CO2 is contained better within the space to smother the flames. [This will need some practice runs.] Note: it might be good to tie two ends to the bottom of the bottom bowl to avoid over-shooting. This would help if, for some reason, this was done alone. And, of course, I'd get some other blankets for a more remote fire and not attach them.

November 19: Dumping the water

Problem: The firefall must be emptied before packing. Ben's courtyard is not all that far from the street, but it might just be too far for my hoses to reach... And it's uphill to the street... How to get the water to the street drain??

Solution: The end of the feed hose has a quick-connect fitting, but I can unscrew this and attatch a piece of pipe welded to a threaded fitting, so now the hose ends in a pipe. I can use the flexible coupling from the water feed to attach pipes to, like the top bowl feed pipe or the fuel tunnel! And if that's still not enough reach, I can simply get a pipe from the local hardware store and attach it. With more flexible couplings, I could extend it indefinitely!

Note for Burning Man next year: get drain piping with diffuser holes to help spread out the drain water. Also, it's good to filter the water a bit before dumping it. An extra flexible coupling in my toolbox wouldn't hurt either.

January: Pumping the fuel

Problem: [This is an old inspiration, but I feel worthy of documenting here -- it's my most inspired inspiration! :) ] How do you pump the fuel without dissolving the pump? Small fuel pumps that run on 110V are not common.

Solution: Well, if I pump water into the fuel tank, and put the outlet at the top because the water will sink, this will force the fuel out the top. The tank must be sealed for this to work.

This is how I ended up handling the fuel for The Ceramic Thing. The tricky part was pumping the water into the fuel tank, because a simple T connection is the same pressure at both ends, and no water will flow through. George helped me build a venturi with a small fuel pipe surrounded by a larger water pipe. But the water pipe was at a narrow part in the water flow, so the pressure was lower in the narrow part, and higher where the water line came out and went into the fuel tank. The difference in pressure caused the water to flow into the fuel tank, and thus the fuel to flow out and into the water line.

I didn't have to worry about this problem in the beginning because the fuel was open to simple atmosphere pressure, and the pumping water line had a higher pressure.

This method of pumping the water has many advantages: first, I don't have to worry about getting a special fuel pump, second, I didn't have to get another pump at all, but most importanly, third, the empty space in the fuel tank was filled with water instead of air and fuel fumes!

I was not able to use this for The Cauldron because the amount of fuel I figured I would be a far more significant water drain compared to the small fuel flow of the Ceramic Thing. Also, it's not a major worry to dispose of 2 litres of water from the small one, but 55 gallons of water -- with unknown contaminants dissolved, which would have otherwise burned off -- was a whole different matter. So I went with a 12V universal fuel pump for a car.