propane freeze spray

[jheissjr]

I made an adapter to turn a propane cylinder into freeze spray. I underestimated how much oil comes out in standard use with the propane. The oil is added in the cylinder to give it the smell. The oil is burned with the propane in regular use and doesn’t matter. For freeze spray, it’s not burned off and the PCB looks like it’s sprayed in oil with a hose. Any ideas for other freeze sprays?

https://www.amazon.com/dp/B0DHQGNLTL?ref=ppx_yo2ov_dt_b_fed_asin_title
https://www.amazon.com/DozyAnt-Universal-Propane-Throwaway-Disposable/dp/B019CND6J2

[antenna]

Butane made for lighters (not pen torches) often has no odorous sulfur compounds.

I'm waiting to see the non-flammable suggestions myself

[amyk]

Propane is just about the worst gas you could use for a freeze spray because of its extreme flammability. R152a, R134a, or R143a as commonly found in "gas dusters" would be far better.

[Someone]

Propane is just about the worst gas you could use for a freeze spray because of its extreme flammability. R152a, R134a, or R143a as commonly found in "gas dusters" would be far better.

Why bother with Hydrofluorocarbons ? CO2 is dirt cheap and just needs some sensible ventilation relative to the volume used.

[jheissjr]

Why bother with Hydrofluorocarbons ? CO2 is dirt cheap and just needs some sensible ventilation relative to the volume used.

What do you suggest for a spray paint can size dispenser?

[Mr.B]

A sodastream cylinder, suitable adaptor and PPE.

[iMo]

Once upon a time on an electronics flee-market a guy showed me a freeze spray intended for "killing the insects". I thought it is a scam so we talked about it and the guy offered to me to show how it works. He sprayed me with it in my hand's palm. Unbelievable pain, I would not do it again. He talked about -40C.

[BradC]

I use Butane frequently.

[Brumby]

I made an adapter to turn a propane cylinder into freeze spray.

I got this far and cringed, for this same reason:

Propane is just about the worst gas you could use for a freeze spray because of its extreme flammability.

I had one experience with a small amount of butane escaping during the refuelling of a butane powered torch/soldering iron that ignited (No, the iron was NOT running during the refuelling, for those who might be wondering.).  The flame was elegant and while it only lasted 3 to 4 seconds, it seemed an eternity as I saw it drift higher and higher.  Until that flame extinguished, I was seriously anxious ... and you want to deliberately spray highly flammable gas into the air.  My suggestion is: don't!

Go for a readily available solution.  Just search for "freeze spray".  I found such products under the brands CRC, Protech, Servisol and Chemtronics in 2 seconds with Google.  There are bound to be more.


While I do not deny the evaporation of volatile gases will produce the desired result, I am ever wary of what could happen if things go wrong.

[RoGeorge]

The cold comes from the sudden release of pressure, so why not using compressed air instead of propane?

Many compressors come with an air tank, and with filters to remove air humidity.  Or buy CO2 cylinders, if for some reason it is not possible to have an air compressor.

[BradC]

The cold comes from the sudden release of pressure

No, the cold comes from the latent heat of evaporation of the liquid in the can. That is a *significant* difference.

Grab a can of freezer spray. Now hold it upside down and spray the gas on your palm. Turn it right side up and spray the liquid on your palm. Which one causes frostbite?

[tggzzz]

Once upon a time on an electronics flee-market a guy showed me a freeze spray intended for "killing the insects". I thought it is a scam so we talked about it and the guy offered to me to show how it works. He sprayed me with it in my hand's palm. Unbelievable pain, I would not do it again. He talked about -40C.

I have, occasionally, used a standard electronics freezer spray to remove warts and verrucas.

That mechanism is very controllable. Yes, you could get it to hurt and possibly damage yourself, but that would require determination and stupidity.

EDIT: I would never apply that so someone else, since I cannot whether I'm cooling their skin too much.

[Ranayna]

Once upon a time on an electronics flee-market a guy showed me a freeze spray intended for "killing the insects". I thought it is a scam so we talked about it and the guy offered to me to show how it works. He sprayed me with it in my hand's palm. Unbelievable pain, I would not do it again. He talked about -40C.

I have, occasionally, used a standard electronics freezer spray to remove warts and verrucas.

That mechanism is very controllable. Yes, you could get it to hurt and possibly damage yourself, but that would require determination and stupidity.

Now i wonder whats in the cans that are sometimes standing on the table at my dermatologist.
These are cold by themselves, there is visible condensation on them.

[tggzzz]

Once upon a time on an electronics flee-market a guy showed me a freeze spray intended for "killing the insects". I thought it is a scam so we talked about it and the guy offered to me to show how it works. He sprayed me with it in my hand's palm. Unbelievable pain, I would not do it again. He talked about -40C.

I have, occasionally, used a standard electronics freezer spray to remove warts and verrucas.

That mechanism is very controllable. Yes, you could get it to hurt and possibly damage yourself, but that would require determination and stupidity.

Now i wonder whats in the cans that are sometimes standing on the table at my dermatologist.
These are cold by themselves, there is visible condensation on them.

I have seen a doctor put acetone into a container, blast cold gas (CO2 from a pressurised ampoule) through it so it forms a slush, and then put the slush on the wart. The acetone and CO2 ampoule can be stored easily for long periods in a cupboard - very practical for occasional impromptu field use.

The physics of a slush would ensure the temperature is in a narrow range. When put on the skin, the skin temperature will be defined by the amount of heat in the slush, which is determined by the heat capacity and mass. Overall the result is that the wart would be cooled down by to a temperature that is better limited than by the uncontrolled application of a freezer spray.

Having felt the desirable temperature once, it isn't difficult to replicate it with the freezer spray. I would never use freezer spray on someone else.

[BradC]

Now i wonder whats in the cans that are sometimes standing on the table at my dermatologist.
These are cold by themselves, there is visible condensation on them.

My dermatologist uses liquid nitrogen. She has this neat little integrated spray bottle thing and a large dewar out the back to fill it up from.

[jpanhalt]

@RoGeorge
It's not only release from pressure.  Heat of vaporization plays a factor when very low boiling liquids are used.

@? dermatologists
A lot use liquid nitrogen, which can be applied by sprayers or on swabs.

1,2-dichloroethane was used years ago in dermatology and for local freezing.  I don't know if it still is used. I use 1,1-difluoroethane, which is common in dusters that are not just compressed air.  I use a bitterant free version called "Gust."  Its availability probably varies by state.  It is also flammable. 

CO2 from compressed cylinders (like used to power airguns, Crosman brand) can be used, but that is probably more expensive.  Larger CO2 cylinders as used in the beverage industry are far less expensive but bulky.  My "man lift" uses them.

Finding something that is non-flammable, cold enough, not too cold, can be easily stored for long periods, doesn't contain non-volatile additives, and doesn't cause cancer if you live in California is difficult.  CO2 meets many of those requirements.

[ifonlyeverything]

Propane is just about the worst gas you could use for a freeze spray because of its extreme flammability. R152a, R134a, or R143a as commonly found in "gas dusters" would be far better.

Why bother with Hydrofluorocarbons ? CO2 is dirt cheap and just needs some sensible ventilation relative to the volume used.

I think you would need a regulator. CO2 tanks are ~800 PSI, propane tanks are ~150 PSI.

[Gregg]

A vortex air cooler system would certainly be safer than propane or any other flammable refrigerant cold spray.  Using propane in lieu of freeze spray is just plain stupid.
One major drawback to propane is that it is heavier than air and tends to accumulate in lower levels; hence it is not recommended for use onboard boats.

[jpanhalt]

I think you would need a regulator. CO2 tanks are ~800 PSI, propane tanks are ~150 PSI.

How is that a serious impediment for those worried about destroying the world or getting cancer (if you live in California)?  I suspect they cost insignificantly more on Amazon" than a propane tank at Home Depot.

*About $22

[thm_w]

Some boiling points for comparison:
- Butane -1°C
- 1,1-difluoroethane -25°C
- Propane -42°C
- Carbon dioxide -78°C
- Nitrous oxide -88°C
- Liquid nitrogen -196°C

For non-flammable stuff CO2 is probably the cheapest, N2O is also quite cheap with the recent abuse craze.

[Circlotron]

Nitrous oxide seems to be readily available and non toxic in small doses.

[Someone]

Nitrous oxide seems to be readily available and non toxic in small doses.

Low Toxicity =/ Low Danger.
Nitrogen and most hydrofluorocarbons simply dilute air. But N2O and CO2 disrupt oxygenation of the blood and present immediate life threatening dangers at much lower concentrations, with N2O being signficantly worse.

[langwadt]

Nitrous oxide seems to be readily available and non toxic in small doses.

Low Toxicity =/ Low Danger.
Nitrogen and most hydrofluorocarbons simply dilute air. But N2O and CO2 disrupt oxygenation of the blood and present immediate life threatening dangers at much lower concentrations, with N2O being signficantly worse.

"inert" gasses are worst because when you need to breathing basically runs on CO2 level not O2 level, so if there is no O2 there is no CO2 in the lungs and you won't even know that you are suffocating

[jpanhalt]

Nitrous oxide seems to be readily available and non toxic in small doses.

Low Toxicity =/ Low Danger.
Nitrogen and most hydrofluorocarbons simply dilute air. But N2O and CO2 disrupt oxygenation of the blood and present immediate life threatening dangers at much lower concentrations, with N2O being signficantly worse.

"inert" gasses are worst because when you need to breathing basically runs on CO2 level not O2 level, so if there is no O2 there is no CO2 in the lungs and you won't even know that you are suffocating

While it is true CO2 stimulates breathing, the converse is not true.  That's one reason nitrogen asphyxiation  for capital punishment is effective and presumably painless.  You just keep breathing regardless of the CO2 concentration and don't notice its absence.

Edit:  Most of the CO2 in your lungs and blood comes from you , not the atmosphere.

[langwadt]

Nitrous oxide seems to be readily available and non toxic in small doses.

Low Toxicity =/ Low Danger.
Nitrogen and most hydrofluorocarbons simply dilute air. But N2O and CO2 disrupt oxygenation of the blood and present immediate life threatening dangers at much lower concentrations, with N2O being signficantly worse.

"inert" gasses are worst because when you need to breathing basically runs on CO2 level not O2 level, so if there is no O2 there is no CO2 in the lungs and you won't even know that you are suffocating

While it is true CO2 stimulates breathing, the converse is not true.  That's one reason nitrogen asphyxiation  for capital punishment is effective and presumably painless.  You just keep breathing regardless of the CO2 concentration and don't notice its absence.

yeh so you don't feel suffocating you just pass out