Megaflow wrote:Your talking $500 in parts and materials
Knowledge on who to
Dont have the info readily avail, but I did not spend over $200.
No machining, all threaded off the shelf brass parts.
thinkcooper wrote:Spectabillis, thanks for the link to McMaster-Carr! They look like a great resource for components. Have you seen any solenoid controlled brass valves for fluid/fuel in their catalog? How about any fluid couplings that can rotate on their axis?
geekster wrote:I think it came to just under 500. Mostly because we had the nozzle made for a higher volume than the standard units so it was still kind of a one-off.
It was a vapor unit. We tried to use a large long pipe as the accumulator and it would have worked too, if there had been a pressure regulator on the tank. What we ended up with was the flaming hairspray can effect. We burned through a 120 gal tank of propane in about 2 nights. There still wasnt enough volume in that 2-inch steel pipe to act as a good accumulator.
thinkcooper wrote:I think this is the only forum I participate on that doesn't have an edit function- hmm..
oh well, anyway-
Spectabillis, do you also know if there is a resource like McMaster-Carr in California, or even better, in the south bay area?
spectabillis wrote: I dont know about the regulator/accumulator thing. But it sounds really strange that a 2 inch diameter pipe could not provide a good volume of vapor, unless it was really short.
Megaflow wrote:Picture the blast from 50 gallon compressor tank filled with propane at 150 PSI, plumbed to a 1" diameter steel pipe, with a 1" whistle valve and good ignition source. You'd be seeing some enormous fireballs with that set-up.
Stop already, you're giving me wood
Megaflow wrote:If you use the $135 valve mc master carr sells it has brass or brnze seats and kevlar stem packing. Using this valve, even though it is more expensive will help to ensure that it wont melt a disc. Remember that you get both heat transfer from the flame and you also get very cold vaporized propane rushing by that disc. My opinion is that even if the ptfe would hold up to the heat the repeated heat cold cycles may take it's toll on the disc.
Ghost Mines and Colored Alcohol Flames
In the normal evolution of fireworks, you learn how to make something; then you make a larger one; then you make an incredibly huge one; then you make a couple more of those; then you start to look for ways to make it more interesting, maybe even prettier and smaller. Well, that's been my experience with liquid fueled fireballs, especially ones that can be fired out of steel mortars.
I started small. A friend of mine, who is a professional storyteller, wanted to create some "atmosphere" at one of his outdoor gigs. He wanted some flames in the background to burn with an "eerie" light. Well, I had a bit of experience with coloring alcohol flames and thought I'd give it a shot.
Green is easy. You mix a teaspoon or two of boric acid in a gallon of methyl alcohol and you're set. The boric acid actually reacts with the methyl alcohol to give you methyl borate, which is volatile. The boron in the flame gives it a very pronounced green color. The mix can be burned in an alcohol lamp or in the open (sterno can sort of thing). My buddy used a stainless steel bowl placed in a dish full of sand. Of course, once he had green he wanted other colors. But, those were a little more difficult.
In order to get an element to color an alcohol flame, you have to get it into the flame itself. And, unlike the boron, it's either tough or undesirable to produce a volatile metal compound. We fussed with that a while until we hit on the idea of a wick. Turned out that a piece of steel wool in the bowl of alcohol did the trick. So now we could produce colored alcohol flames in a rainbow of colors.
The elements chosen are obvious, but the actual chemicals are a compromise among solubility in methyl alcohol, cost, and availability. Turns out that roughly 50 grams per gallon always works. In some cases it doesn't all dissolve, but with calcium chloride or sodium chloride, who cares?
· Red: Lithium chloride (actually any soluble lithium salt)
· Orange: Calcium chloride
· Yellow: Sodium chloride
· Green: Boric acid
· Blue: (nothing - alcohol burns blue)
· Violet: Potassium iodide
This was a fun, low-level, non-pyrotechnic back yard project. The next step was to go large. I had been firing gasoline fireballs out of some mortars I had. Starting with a half gallon I had gradually worked up to blowing three gallons of gasoline out of a six-inch steel mortar using a charge of 40 to 120 grams of FFG black powder for lift. So why not shoot colored alcohol flames instead? Several folks at the "Do-It" event had a chance to witness my first shots of the half-gallon "Lampare Mines". Admittedly that was a bad name because many people were expecting an aerial effect. Upon seeing a daytime mpeg of these colored alcohol fireballs Harry Gilliam coined the phrase "Ghost Mines". I like it.
I'll launch some of these at the Western WinterBlast XII using the following gear:
Mortar: 4-inch inside diameter iron pipe, 2 feet long
Lift: Place 40 grams of FFg black powder, a pinch of sponge titanium, and an electric match in a very small (jeweler's supply) zip lock plastic bag. Squeeze all the air out, and tightly wrap it with both clear packing tape and then masking tape seal it against alcohol seeping in.
Fuel: One gallon of methyl alcohol with 50 grams of coloring agent
Method: Fill mortar with alcohol and coloring agent solution. Lower the black powder charge into the mortar. If the charge is tightly packed it won't float. From the friendly end of a 50-foot electric shooting wire, fire that thang!
Drawbacks: Typically there is some burning alcohol left behind in the mortar: HDPE and paper don't last too long.
Supplies: I get the methyl alcohol at the local lab supply, or fancy hobby shop, for $10/gal. Ethyl alcohol may work on some but the denaturing agent tends to give a yellow flame. I hear the boric acid doesn't work with ethyl alcohol.
No Man's Land: To get a really beautiful sky-blue color, add six grams of copper chloride and 200 ml. of methylene chloride (chlorine donor) to the gallon of methyl alcohol. Great color but it also makes a phosgene byproduct, something you might not want indoors. Any chlorine donor will do that. That is why I shied away from strontium and barium
flamebrain wrote:The Bonefire & Black Rock Blaster lightweight personal flamethrowers are not cheap, that's because of the way they're made. They're designed to stand up to the harsh playa conditions and always perform, and look good! They are made entirely out of corrosion resistant materials and many of them have been to Black Rock City for the last three years and still function perfectly...
crazybuthappy wrote:... I think he/they are turning out a good product for a price some people are willing to pay. Plus he/they are still active in helping the less experienced.
The higher cost is in a design that requires little to no maintenance and is safe. Sure you and I can make <$100 flamethrowers because if you design and build a flamethrower yourself you intimately understand the limitations and risks. ..I think competition in this market would be great,
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