Leave it to someone from So Cal to comment about supposed "greenhouse gases" that many of us do not even think one iota about....

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Eliminating all possible ignition sources under any circumstances other than controlled laboratory conditions could be problematic (flying on a Fall day while wearing a sweater would present a possibility for a static discharge, for example).

Having the propane ignite after leaving the nozzle would be cool, but if any atmospheric air remained inside the Cold Power rocket engine, it could explode and throw shrapnel. Also, even if the engine didn't explode, the burning propane would melt and ignite the engine's plastic nozzle bell.

This is not to say that a propane-powered Cold Power model rocket would necessarily be impractical. If the engine was designed from the ground up with propane in mind (having a blow-out safety plug like those used in pressure cookers to prevent them from exploding, for example), such an engine could be operated safely. Charging the engine with carbon dioxide or water before filling it up with propane would force all air out of the engine, which would eliminate the danger of an explosion while loading propane into the engine.

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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

A local friend of mine has a herd of draft cross horses and light horses who emit methane (another greenhouse gas) all day, every day, but I don't lose as much as a microsecond of sleep worrying that they're "killing the planet."

It's all a matter of quantity. In 1910 many people freaked out when it was announced that HCN (hydrogen cyanide) had been spectroscopically observed in Halley's Comet, whose tail the Earth was to pass through. Other than those who had heart attacks or committed suicide after hearing the news, no one died of comet-borne cyanide poisoning because the actual quantity was so tiny, diffused as it was throughout millions of cubic miles of the near-vacuum of the comet's tail.

Plutonium and uranium are even better examples. While I certainly don't advocate dumping them openly (or detonating nuclear bombs anywhere except underground in tests), think about all of the weapons grade uranium and plutonium that was pumped into the atmosphere and oceans during decades of nuclear weapons testing on the Earth's surface, in the atmosphere, and in space. While the surface and undersea tests certainly caused illness and even deaths in their immediate vicinities, the Earth's biosphere as a whole shows no ill effects.

When you fry an egg in your kitchen, you produce a dangerous toxin called acrolein (see: http://en.wikipedia.org/wiki/Acrolein ), which was used as a chemical weapon in World War I. But because the amount produced is so small, it presents no danger unless you're frying the egg aboard a submarine or a spaceship (preferably rotating to produce artificial gravity!) with an inoperative air filtration system.

That is why I don't worry about Freon-12, R-134a, carbon dioxide, or whatever the latest "THIS-WILL-WIPE-OUT-HUMANITY!!!" substance it is that has the greenies running around like chickens with their heads cut off. This notion that humans can pump enough of X substances into the environment to destroy all life on Earth is hubris wrapped in faux humility. But it doesn't mean we all can't try--let's go burn some black powder and ammonium perchlorate/aluminum powder!!!

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

I don't quite get the "flammable airbrush propellant is totally out" argument. So it contains propane... big deal... Ever think of how much propane is being vented through the airbrush, usually into a confined space (indoors) as a person is airbrushing a model?? These CP rockets are being launched outdoors, and usually there is SOME kind of breeze blowing, so any 'venting' from the motor and filler and the vapor cloud from liftoff should rapidly mix and dissipate.

Just don't launch the things electrically (some of the old Estes/Vashon stuff used nichrome 'burn wires' to launch the rocket and of course red hot nichrome in the vicinity of mixing air and flammable propellant (propane) vapors wouldn't be a good idea, but so long as you aren't smoking or launching next to a campfire or something I wouldn't see any problems with using a propane-containing airbrush propellant for fuel. In fact I'd say using a flammable propellant for airbrushing indoors, with SO many ignition sources and a contained area with little air interchange to dilute the vapors, and capable of acting as a 'pressure vessel' in the event of an unintended ignition of the vapors (house containing the vapors and blowing up) would be a FAR more hazardous proposition!

Of course I didn't really get the arguments some people used against propane-based R-12 Freon replacements, either-- yes it's flammable, but so is gasoline, rubber, plastic, and myriad other things used on vehicles every day, and especially in farm environments where machinery often gets covered in flammable plant dust/clippings/chaff and other such detritus... The amount of 'flammable material' is negligible compared to the amount of flammable material in the fuel tank and used in the construction of the vehicle (especially so with farm equipment, especially harvesters, usually carrying THOUSANDS of pounds of flammable grain/cotton/hay/other produce.) We 'deal' with the risks of driving a vehicle carrying 20+ gallons of highly flammable gasoline every day, made with hundreds or thousands of pounds of flammable plastic/rubber and assorted compounds, even more so in agriculture driving combines/cotton pickers/hay balers made of the same sorts of stuff carrying THOUSANDS of pounds of flammable cotton/grain/hay and associated flammable dust and chaff, yet wince at the idea of putting a pound of propane-based refrigerant into the air conditioner system??? Seems a bit rediculous to me....

Like I said, of course greater care would be called for, but I wouldn't see any particular risks with using a flammable airbrush propellant in cold power rockets that we don't already face using flammable solid propellants which can cato...

JMHO! OL JR

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The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!

Here's the skinny on the "environmental risks" of these propellants...

I went to mechanic's school back in 90-91, just when Freon 12 was being phased out. We had to get 'certified' on Freon reclamation equipment in order to work on freon systems. The law required that refrigerants be 'reclaimed' by being pumped out of the air conditioning system prior to the system being 'opened' (hoses taken loose, components replaced, etc.) and made it 'illegal' to simply "vent" the freon (unscrew a hose fitting until it started 'sissing') which was standard operating procedure up to this point. All this was due to the "perceived" damage to the OZONE LAYER supposedly caused by fluorocarbon refrigerants. (Of course NOBODY has EVER been able to explain how these heavier-than-air refrigerants make their way 80 miles up to damage the ozone layer-- we were warned when working in a shop never to vent freon next to a service pit-- it would sink and flow along the floor like water and fill the pit up, displacing the air, and could cause mechanics working in the pit to pass out or asphyxiate!)

Now the main point of contention was, that this 'reclamation equipment' costs thousands of dollars, and you need a completely seperate system for each kind of refrigerant. R-134a was starting to come out in cars at the time, though most of the vehicle fleet still on the road at that time still used R-12 freon. IF you serviced HD trucks, reefers, residential/commercial AC and freezers, etc. you'd probably have to have an R-22 system as well, possibly more with some of the lesser-known specialty refrigerants in use, but those were the main ones. SO now you have to buy at least 2 several-thousand dollar reclamation units to do AC work. There was a LOT of grumbling in the industry over that! It was made a little more palatable by two things-- EPA banned further production of R-12, but allowed the considerable existing stocks to be sold and used, which drove the prices through the roof, and the reclamation equipment was usually equipped not only to capture the old refrigerant in the vehicle, but to filter and purify it so that it could be re-used in the vehicle. SO Granny Schicklegruber drives in her Caddy because the AC doesn't work. You determine her compressor is shot, so you evacuate the system with your reclaimer, disconnect the lines, replace the compressor, reinstall the lines, pull a vaccuum on the system, and refill it with the same R-12 you pumped out of the system, leak test, road test, and charge her for the "new" freon, new compressor, and labor. Note you reused her old freon, which cost you nothing, but you charged her for NEW freon since you reclaimed and filtered it through your multi-thousand dollar reclamation machine.

Now the REAL reason that R-12 went away, was DuPont's patent on freon was expiring and it was going to be open season on freon production-- any chemical company that wanted to could make the stuff and not have to pay a royalty to DuPont. SO, "miraculously" it was found to be 'eating the ozone layer' and had to be 'banned', and so DuPont trotted out it's 'ozone-safe replacement' product, R-134a, which is actually a poorer refrigerant with higher vapor pressure, higher system pressure, less latent-heat removal capacity, and is slightly corrosive, requiring special seals and materials in the refrigeration system that was not necessary for R-12, so it's less efficient and more expensive to engineer a system to use. Incidentally, EPA also ruled that even though R-134a was "ozone safe", mechanics STILL aren't allowed to vent it from vehicle AC systems-- they MUST use a refrigerant reclamation unit. Interesting how that works isn't it?? EPA requires it "must not be intentionally released" while approving it's use as aerosol propellants which by definition "release" it into the atmosphere. BUT, DuPont is happy, EPA is happy, and the sheep-greenies are happy that they "saved the ozone layer". What a crock!

In the meantime, millions of people in developing countries were denied access to cheap refrigeration equipment running on R-12, for preserving foods, medicines, and providing air conditioning in hospitals and such, causing untold numbers of deaths. Old farm machinery operating on family farms across the US which had R-12 air conditioning systems found they couldn't get the freon needed to 'top up' the system before harvest in summer, without having to go take a long expensive refrigeration course, obtain a "Freon purchasing license" and buy a reclamation system. So, a flurry of "non-regulated" freon replacement materials started flooding the market for folks who couldn't afford the expense of all this nonsense. Most were propane or butane based refrigerants, which were technically 'illegal', but then poor folks has poor ways as my grandma used to say. THese were touted as "highly dangerous" by the EPA and other regulating authorities, but persisted anyway due to it being the ONLY affordable alternative. Some folks concerned about flammability issues chose to use R-134a in their R-12 systems, but mixing them was 'illegal' under EPA rules and would seriously piss off any mechanics who found their reclamator cross-contaminated by mixed refrigerants. (most have a 'trouble light' that lit up if mixed refrigerants were detected by the unit). THis whole mess was a money-grab BS exercise...

Now we come to the sheep-greenie arguments. Fluorocarbon refrigerants supposedly destroy the OZONE LAYER. There are MYRIAD other gases, most naturally-occuring volcanic gases and such, which are released in the MILLIONS OF TONS each year by volcanoes and other naturally occurring phenomena which destroy ozone. Heck even energetic UV light and solar particles in the upper atmosphere destroy and continually re-create ozone; that's how it got there in the first place! But nothing must do, REFRIGERANTS MUST GO!!!!

Light hydrocarbons like methane, propane, and butane (methane is lighter than air, propane is right around the specific gravity of air, and butane is heavier than air) are GREENHOUSE GASES. Methane is the most troubling to the sheep-greenies of all, because it is supposedly a STRONG greenhouse gas many times more efficient at solar heat trapping in the atmosphere than carbon dioxide... (of course the environmental nutjobs never mention that the MOST efficient greenhouse gas, THOUSANDS of times more powerful at heat trapping than CO2 or even methane, is WATER VAPOR (yep, CLOUDS!) and there is NOTHING we can do about THAT; heck without water vapor, earth's mean temperature would be about 20 below zero and life couldn't exist!) This is why the greenie-sheep are SO worked up about cow farts and other such stupidity. Nevermind that their average beloved swamps and natural phenomena like volcanoes can release MILLIONS OF TIMES more methane each year than all the livestock on earth combined... that's not important... SO their argument goes that hydrocarbon refrigerant replacements are greenhouse gases, (and flammable) and the fluorocarbon refrigerants are ozone-depleters (though inflammable).

So pick your poison and fly with confidence!!! OL JR

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The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!

A Vashon two stage was recently sold on Ebay. I followed it, but the price went way over my maximum.
Two Stage Cold Power

However, there was a nice link in the Item Description which finally made it clear to me how the two stage scheme works.

Vashon Two-Stage Instructions

I have one of the Shrike CP rocket boosted gliders. I've been working on an adaptation for fueling it. I found the R134A propellant at Walmart for something like $5 - $6 per can. I found a brass threaded valve assembly which fits on top of that sort of can at AutoZone.

I found a thread adapter from the outlet of the AutoZone valve to the original Vashon/Estes CP fill valve at Home Depot. However, the joint is leaky and so unsuitable. But I've bought some O'rings which may do the trick.

If so, I'll have a nice screw-valve attachment for R134A cans which attaches to the stock filler for the old CP stuff.

It sure would be nice to see someone make new cold power equipment.

My first rocket ever was a Valkryie II. I was into electronics at a young age and Lafyette (sp?) Electronics sold the Valkyrie II and had it in their catalog. It was a Christmas present. I think there was an Estes catalog in there which led to the BP rockets.

Leo's CP engine looks like one of the ones used in the CP convertibles. The disadvantage it has with respect to the older Vashon engines is that the plastic nozzle has a habit of breaking off. At least, that's what happened to the one cold power convertible that I had as a kid.

I think that launcher which grips and plugs the nozzle puts a lot more stress on the nozzle than the regular Vashon engines with a plug and pin arrangement.

*GOLF TOURNAMENT APPLAUSE*

Thank you for posting all of that useful information! I've saved it for future reference.

Speaking of "environmentally UN-friendly" refrigerants, do you remember when refrigerators and freezers used sulphur dioxide (SO2) as a refrigerant? About the only good thing about it was that you didn't need anything other than your nose to tell you when the coils or compressor had sprung a leak! In the event of a really large leak, people ran outside with their eyes burning... :-)

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

I was thinking in terms of a company (Estes, Quest, Semroc, etc.) that might contemplate producing new Cold Propellant model rockets in today's legal environment. I would have no qualms about flying such rockets using propane myself, but if I were a lawyer advising such a company, I would be concerned about possible accidents involving the propane that could put them out of business.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Sorry, before my time-- I'm only 38...

I know that in our refrigeration and AC courses we learned about the history of refrigeration and refrigerants, and that the first commercially viable refrigerant was AMMONIA! When THAT stuff sprung a leak, you KNEW it!!!!

I've worked with anhydrous ammonia on the farm-- it's a common fertilizer, and my dad nearly got gassed by the stuff when I was a kid, and so we switched to liquid aqeuous ammonia and never looked back, though I did use dry ammonium nitrate a couple years.
I was on my way to school one morning when a worker, running a tractor for one of the big local farmers, had a hose rupture on the anhydrous wagon he was pulling behind a row disk hipping up beds to prepare for cotton planting-- that liquid ammonia was spraying out and instantly boiling off like propane and had a HUGE white cloud of vapor formed, and Pedro goes running into it trying to get to the valve on the bottom of the tank to shut off the busted hose... NUTS!!! That stuff can kill ya!

I doubt that the sulfur dioxide would be very good for you either...

Later! OL JR

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The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!

Yeah, unfortunately we live in a litigious society...

We had several propane powered tractors here on the farm over the years, mostly when I was a kid, but one we still used up til a few years ago. Dad taught me how to refuel them from the butane tank using the hose and valve and bleeder valve to lower the tank head pressure to let liquid flow into the tank. I used to refuel that tractor from the time I was 15 on, because that was our primary hay-raking tractor and that was one of my main jobs. I used to hate refueling that tractor because the stench from the vented propane would draw a cloud of flies zipping around the tractor and butane tank thinking something had died, but it was funny when some of them would fly through the escaping vapor and freeze and fall out of the air!

One day I hooked up the hose and screwed on the bleeder and started refuelling a tractor that had been sitting up a pretty long time. I guess there must've been a spider or a cocoon or something inside the filler, because after I filled the tank and shut off the supply hose valve, I unscrewed the hose connector from the tractor fuel tank and it IMMEDIATELY started hissing liquid propane. It of course boils at like 20 below zero, so the valve and hose iced over, and I couldn't retighten it, so I went and got my welding gloves and tried to screw the hose back on, until my gloves started to freeze, so I unscrewed the valve and the tank fitting sat there smoldering cold vapors and intermittently dribbling freezing liquid propane that ran down the side of the tractor boiling furiously as it touched room-temperature metal, causing a huge vapor cloud that was drifting on the breeze down the length of the field toward the highway. Now if the cloud is dense enough to SEE it, it's certainly thick enough to ignite-- so I was worried one idiot on the highway carelessly tossing a cigarette out the window would blow us all to kingdom come-- but there's no way to shut off the valve on the tractor tank, because it's a check-valve. My Dad showed up and wondering what's up, suggested I just leave it, since you can't realistically work on it with it frothing freezing liquid propane at you; sometimes they do that he said and you just let the tank boil dry, then clean out the valve and it will work fine. I told him I didn't like that idea because the gentle breeze was carrying the fumes toward the highway, and asked if he had any other ideas-- he said, "well, sometimes you can smack it with a 2x4 and get it to seat" so I got a 2 foot piece of scrap lumber we use for blocking up machinery and smacked the valve lightly a few times and it finally snapped shut.

I guess I have a higher danger tolerance to such things than the average joe... LOL OL JR

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The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!