Thought i bought pressurized air

[Jonty]

Isobutane and propane are the propellants to make whatever is in the container come out of it. I'm not sure why an inflamable gas has to be used but thats why it generally says on the product not to use it near naked flames or incinerate the empty can.

Things like hairspray contain these gases - why spray an inflamable gas onto your hair for goodness sake!

[DanU]

Practically all of those "canned air" cleaners use some form of gaseous hydrocarbon, florocarbon, or hydroflorocarbon. They contain no real air whatsoever. The advantage over using plain pressurized air is that these substances can be compressed into a liquid at room temperature. As you know, liquids are much denser than gases, so you can put a lot of "canned air" in can.

The liquid itself is harmless. It's the cold that may cause damage. Also, since it's not really air, you can asphyxiate (someone help me with the spelling!) if you breath too much of it.

[Graham]

As Jonty says, the isobutane and propane are the propellants, these are used nowadays instead of the old ozone harmful chemicals, I agree its odd to use flammable gasses though.

G

[hotrodder]

friendly to the ozone layer
deadly to humans

[DemonKnight]

I just the air compressor in my garage. :p

[Goldwingnut]

Miller-Stephenson has R-134A compressed "air". Non-flammable, environment friendly. Definitely cold if you want that.

If you spray it on a wet surface, the "Freon" and water both evaporate almost instantly, so you can dry things with it.

200 PSI out of a fresh can.

[club_med]

I just went out and bought some pressurized air to clean the fan and some internals of my computer, this is the first time i use it so i have a question.

While spraying, occasionaly some liquid shoots out, it evaporates immediately and makes a hissing sound, i tried it on the table and on my lamp, same effect = flow of air interrupted by sporadic bursts of this fast evaporating liquid (hissing sound everytime),the liquid leaves no traces.

Is this normal ?.
Will this liquid damage any electronics ?.
What is this liquid ?

Container says "Dust Buster, 400ML" by ALBINAR.

Also says "New Formula" near the bottom.

As far as i understood it contains Isobutane and Propane.

It says its for hi-fi, photo, computer and lab use, but im just worried about the liquid since this is the first time im using pressurized air.

Hope the info helps,

Thanks for your help!,
cm.

[club_med]

Sorry if i seem to be over-reacting he he http://www.sysopt.com/forum/smile.gif

cm.

[SysOpt]

The liquid is normal but it may damage stuff. The trick to keeping the liquid from coming out is to hold the can level (don't turn it on its side or upside down) and spray in short bursts.

[club_med]

Thanks for advice Sysopt ! http://www.sysopt.com/forum/smile.gif.

Just out of curiosity, why is there liquid when its supposed to be pressurized air in it ?.

cm.

[Undeadlord]

Any you know whats really fun? http://www.sysopt.com/forum/smile.gif If you turn most of those cans upside down, they will spray out a jet of pure FREEZING liquid. Kinda fun to spray on people http://www.sysopt.com/forum/wink.gif .. Careful though that liquid is COLD COLD .. and probabl not too healthy http://www.sysopt.com/forum/smile.gif But it is a kind of fun trick!

Undealord

[Philip1952]

R134 is not that friendly. It is made from some form of toxic waste that is refined. I haven't been able to find out what yet. It is corrisive to alu. that is used in automotive air conditioner systems. When it first came out. The life of a new system was rated for 7 years. Ford,Chevy and Dodge wouldn't tell you that when you bought the car. But KW, FrieghtLiner and PeterBuilt did. They gave you the option to stay with R12 if you wanted it. Plus try to find a service company that will work on a R134 refer unit in the field. That also goes for the refeg you have your favorite cold drimks stored in also. Most service companys tell you to buy a new one.
So I wouldn't use it as a spray for cleaning. The industry that mfg's R134 is guarding the secret of its composition very closely for some reason.

[This message has been edited by Philip1952 (edited 05-03-2001).]

[club_med]

Respect Neon, that was a great post, thanks for info dude !.

On a lighter note, i tried what Undeadlord was talking about on my brother, that stuff is cold ! http://www.sysopt.com/forum/wink.gif.

cm.

[Neon]

I did a little digging, and found some info on R-134a. Google searches:
r-134a: 15,200 hits
r-134a formula: 262 hits
hfc-134a synthesis 330 hits

R-134a (aka HFC-134a) is 1,1,1,2-tetrafluoroethane, formula CF3CFH2. The main manufacturers seem to be DuPont, ICI, Honeywell, Praxair, and Atofina. There are 2 main ways to make it commercially. The more common method uses trichloroethylene, hydrogen fluoride, and a catalyst. Details of the chemistry and manufacturing process can be found here: http://chemcases.com/fluoro/fluoro14.htm

Supposedly HFC-134a was tested for corrosivity effects on aluminum early on, and was found to be inert. Examine the MSDS (Material Safety Data Sheet) that come from the munufacturers, such as this excerpt from Honeywell: http://appserv-a.alliedsignal.com/prodcat/Pdfs/FLO/MSDS/gtrn134a.pdf

10. STABILITY AND REACTIVITY

NORMALLY STABLE? (CONDITIONS TO AVOID):
The product is stable.
Do not mix with oxygen or air above atmospheric pressure. Any source of high temperature, such as lighted cigarettes,
flames, hot spots or welding may yield toxic and/or corrosive decomposition products.

INCOMPATIBILITIES:
(Under specific conditions: e.g. very high temperatures and/or appropriate pressures) * Freshly abraded aluminum surfaces
(may cause strong exothermic reaction). Chemically active metals: potassium, calcium, powdered aluminum, magnesium
and zinc.

HAZARDOUS DECOMPOSITION PRODUCTS:
Halogens, halogen acids and possibly carbonyl halides.

It looks like HFC-134a can react with finely powdered aluminum under very high temperature and/or pressure, which would eventually cause pitting of the aluminum and degredation of the HFC. This does not happen near room temperature and pressure, so it is ok to use in spray cleaners. In fact, it is used in metered dose inhalers for asthma relief: http://www.arap.org/adlittle/11.html

Certain compressor seals in old air refrig systems are known to leak when exposed to HFC-134a, and that has caused problems for retrofitting. It is pretty well documented by now: http://enviro.nfesc.navy.mil/p2library/cgi-bin/p2h_datasheet.cfm?itemID=67 http://www.epa.gov/ozone/title6/609/retrguid.html

As for the systems not lasting as long, I think that many "durable goods" are no longer manufactured to be durable. For example, many VCR's aren't worth the expense of repairing, you just throw one away if it breaks.