A Dollar of Fun

[Mark]

I took the day off from work and after an early afternoon movie went to some flea market kind of event that sold junk essentially, to benefit some hospital organization. Boxes of bolts, rusty old tools, and books and little brass vases, and then there it was, painted with high temperature chalky black paint and simple, just waiting for me. With a piece of masking tape and a dollar price written on the tank, I couldn't resist. The potential pulsating combustion device had a 3/4 inch pipe thread in the top of this tank/bottle. The valve was absent. So I snatched it up and carried it with one finger down the hole. It is about 5 inches in diameter and something around 14 inches tall but don't quote me. I could see a little fleck where the tank was once green. I tested it with my neodymium magnet and it locked on and was hard to pull off. The bottle has a nice feel to it, heavy, but not too, and shapely somehow.
Now for the interesting part. I methanoled in a splash or two from a Boston brown bottle I store smaller portions of alcohol in. It did the obligatory whooose/hiss and then when up and down the scale in frequency not making up its mind for several seconds and then fell into this enchanting woof, woof, woof, as lazily as a bottle could without giving out, some sort of slow motion film capture it seemed. So it ran like this for around a minute more, hardly exerting itself, flaunting how it could almost quit and still one or two pulses a second stable, heartbeat without flaming out. It was a very pleasant quiet sound as if hardly anything were occurring. Yet the bottle was quite hot when the event was over.
Next, being one to have 3/4 inch pipe nipples around, I screwed in an arbitrary 3 inch long nipple and poured in about a cup of methanol a few hours later after the bottle cooled. I knew this was going to make a stronger hiss on the first pulse, and it did and fluctuated up and down the frequency scale again not giving any hints as to whether it would live or die, but with the heat building in the bottle I felt a great possibility of it flaming out, becoming too rich to support combustion, alcohol probably boiling. Yet I was happily mistaken.
The thing started to pick up the pace, like the engine in the movie Flight of the Phoenix, growing stronger with less and less hesistancy with each transmogrification until it climbed into a steady high tempo wing-beating black beetle ready to take off. What the heck was happening I wondered, I didn't know, but I liked it very much. A 6 to 8 inch steady pale pink and yellow-tinged flame ejected from the nipple nozzle and my first thought was that how pretty it would be if I tinctured the methanol with boric acid powder, to rheostat up the light with a vivid green genie coming out of the bottle.
I suspect this bottle may have been an oxygen tank because of the green paint underneath, and if you can get your hands on one, what a remarkable toy to run so strong, long, and steady with a slight modification. I once made a trick rocket that would shoot a foot long flame idling on the launch pad, until the faster burning fuel was reached. I delighted in saying I guess it isn't going to go, laughing to myself, as they and I intensely watched from a safe distance all the same, and then it took off grandly on course. That's what this black bottle did for me today, it beetled around and then hoodwinked me buzzing strong and long, nothing getting in its way. All I could do was watch and watch in amazement, looking around the yard from time to time, detecting the echo off the house and taking in the overall effect of simple jam jar par excellence, perfect synchronic sound.
Mark

[Mark]

I took the day off from work and after an early afternoon movie went to some flea market kind of event that sold junk essentially, to benefit some hospital organization. Boxes of bolts, rusty old tools, and books and little brass vases, and then there it was, painted with high temperature chalky black paint and simple, just waiting for me. With a piece of masking tape and a dollar price written on the tank, I couldn't resist. The potential pulsating combustion device had a 3/4 inch pipe thread in the top of this tank/bottle. The valve was absent. So I snatched it up and carried it with one finger down the hole. It is about 5 inches in diameter and something around 14 inches tall but don't quote me. I could see a little fleck where the tank was once green. I tested it with my neodymium magnet and it locked on and was hard to pull off. The bottle has a nice feel to it, heavy, but not too, and shapely somehow.
Now for the interesting part. I methanoled in a splash or two from a Boston brown bottle I store smaller portions of alcohol in. It did the obligatory whooose/hiss and then when up and down the scale in frequency not making up its mind for several seconds and then fell into this enchanting woof, woof, woof, as lazily as a bottle could without giving out, some sort of slow motion film capture it seemed. So it ran like this for around a minute more, hardly exerting itself, flaunting how it could almost quit and still one or two pulses a second stable, heartbeat without flaming out. It was a very pleasant quiet sound as if hardly anything were occurring. Yet the bottle was quite hot when the event was over.
Next, being one to have 3/4 inch pipe nipples around, I screwed in an arbitrary 3 inch long nipple and poured in about a cup of methanol a few hours later after the bottle cooled. I knew this was going to make a stronger hiss on the first pulse, and it did and fluctuated up and down the frequency scale again not giving any hints as to whether it would live or die, but with the heat building in the bottle I felt a great possibility of it flaming out, becoming too rich to support combustion, alcohol probably boiling. Yet I was happily mistaken.
The thing started to pick up the pace, like the engine in the movie Flight of the Phoenix, growing stronger with less and less hesistancy with each transmogrification until it climbed into a steady high tempo wing-beating black beetle ready to take off. What the heck was happening I wondered, I didn't know, but I liked it very much. A 6 to 8 inch steady pale pink and yellow-tinged flame ejected from the nipple nozzle and my first thought was that how pretty it would be if I tinctured the methanol with boric acid powder, to rheostat up the light with a vivid green genie coming out of the bottle.
I suspect this bottle may have been an oxygen tank because of the green paint underneath, and if you can get your hands on one, what a remarkable toy to run so strong, long, and steady with a slight modification. I once made a trick rocket that would shoot a foot long flame idling on the launch pad, until the faster burning fuel was reached. I delighted in saying I guess it isn't going to go, laughing to myself, as they and I intensely watched from a safe distance all the same, and then it took off grandly on course. That's what this black bottle did for me today, it beetled around and then hoodwinked me buzzing strong and long, nothing getting in its way. All I could do was watch and watch in amazement, looking around the yard from time to time, detecting the echo off the house and taking in the overall effect of simple jam jar par excellence, perfect synchronic sound.
Mark

Footnote : I thought the black paint was the high temperature stuff but it was not, the bottle smokes on the outside when it gets running hot, but the paint didn't bubble or burn off. I thought the smoke was coming from the underneath layer of green paint somehow. I wondered what the oily, tarry residue droplets were inside the nipple I had screwed on after the long, strong, run. Apparently, the smoke from the paint was ingested into the tank from the outside smoking layers of now rubbery paint I can scrape with a finger nail like tar. Before the paint had the exact appearance and texture of some smooth matte surface high temperature barbaque grill paint I had used in the past.
Instead of showering my garage with black dust and green paint, I'm going to put a wire buffing wheel on an electric drill and get that yucky stuff off the tank in the backyard where I won't have to clean up and then put some high temperature paint on it. It really is an interesting jam jar, it makes steady popping sounds like the end of a towel would make when snapped. Bap, bap, bap sounds with perfect staccato rhythm minutes on end.
I bet this tank would really boil water if I jacketed it in a 10 gallon drum of water. More naivete to follow as testing proceeds with longer nozzles and water baths.
Mark

[Mike Everman]

sounds like good clean fun, Mark. Is it impossible for this type of setup to be coaxed in to detonations?

[Mark]

sounds like good clean fun, Mark. Is it impossible for this type of setup to be coaxed in to detonations?

Here's a good clean fun tip. Because I live in Florida, my Dynajet petals rust quickly outside in the garage. I take a bit of oil and lightly coat the petals to prevent rusting, wiping off any excess. Yet, today's tip is this. I spent five minutes trying to start my Dynajet, running an entire tank of 150 psi through it, twice I took the head off to see if I was getting a good spark. I knew the fuel and air were going in good. And yet this same obstruction happened to me before and I thought I could get around it.
If you have ever layed something on an 1,2,3 block or some very flat surface you can often lift it by the vacuum formed. As soon as I went into the garage and removed the reed and wiped the entire thin film of oil off the reed and reed plate, what a difference that makes. I put the head back on and it instantly started machine gunning a few fierce bursts and then took off wailing to my delight. The only reason I started it today was that the Naval Air Station grunts were playing their music blarring into my forresty backyard that shares a fence with the Air Station work/construction yard. It was some sort of small beer party, and foul language to boot. Anyway, one of the Blue Angels flew over my house on some manuever for the big air show today about 6 miles from here. The jet noise was just before my Dynajet ripped a goodly amount of decibels into the picnic partiers. I let the Dynajet run for a good minute raising the fuel level to keep it rich hoping it wouldn't melt some part of engine running red hot static and no cooling air. When it stopped, I heard the stunned declaration, "What the hell was that?!!!" I have to admit it was kind of funny and even the mysterious people beyond the trees and shrubs,(20 feet or so from my Dynabark Sawhorse), (I personally walked out about 30 feet of air hose and extention cord to optimise the proximity effect), oddly some may have liked the mystery noise in some strange way.
To make a long story short, you can blast a ton of air through the body of a Dynajet with a fog of fuel and try lean and rich blasts of air at many settings, but you won't start the Dynajet if the tiniest most important, seemingly insignificant feature is missing, the reeds must be able to walk up from humble beginnings, as soft as a butterfly, flutter feedback, yes starting with the tiniest of spasms. How effortless and rewarding it is to know attention to little details makes all the difference.
Mark