Well, I was watching CNN and it looks like the Postal workers now are armed with a new weapon.. Against terror of course. THe whole cant read someone elses mail thing is out the window it looks like, they can spray this go on the letter and read through the envelope.. It seems implausable but its CNN, they dont lie right? well ANYWAYS, I now have a nice stash of black construction paper...
Yes, that would work nicely as the outside sheet.
"You spray it on and it temporarily makes the envelope clear," said Robert Schlegel, vice-president of the makers, Mistral Security, of Maryland. "It leaves an odor for 10 to 15 minutes, but there is no smudging of ink, no stain, no evidence at all. The envelope is transparent for a few minutes and you can respray it hundreds of times without leaving any stain."
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end. The USPS won't be checking mail this way anytime soon. If they were they would use some sort of freon recovery system to contain costs. Oh, well, it will soon be time to go buy $2.95 stamps to pay for UV, E-beam, freon and zoot suits. Mike
on Tue, Oct 30, 2001 at 10:25:54AM -0800, mmotyka@lsil.com (mmotyka@lsil.com) wrote:
Well, I was watching CNN and it looks like the Postal workers now are armed with a new weapon.. Against terror of course. THe whole cant read someone elses mail thing is out the window it looks like, they can spray this go on the letter and read through the envelope.. It seems implausable but its CNN, they dont lie right? well ANYWAYS, I now have a nice stash of black construction paper...
Yes, that would work nicely as the outside sheet.
Or "security" envelopes, possibly.
"You spray it on and it temporarily makes the envelope clear," said Robert Schlegel, vice-president of the makers, Mistral Security, of Maryland. "It leaves an odor for 10 to 15 minutes, but there is no smudging of ink, no stain, no evidence at all. The envelope is transparent for a few minutes and you can respray it hundreds of times without leaving any stain."
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end.
First, is that what this spray is? Any information on the chemical
composition?
Freon's pretty chemically inert. That's among its advantages, though
it's a liability in the upper atmosphere. Other options might be some
indicator that notes a rapid change in temperature (evaporating
refrigerant does a nice job of lowering temperature quickly), or
presence of a fluid. Even a nonreactive chemical could float something
loosely applied to a letter.
Peace.
--
Karsten M. Self
At 14:40 -0800 10/30/01, Karsten M. Self wrote:
Yes, that would work nicely as the outside sheet.
Or "security" envelopes, possibly.
I just tried a can of compressed air (upside down so it sprays liquid), It is really, 1,1,1,2 Tetrafluoroehtane, not air. But anyway. It doesn't make a security envelope transparent but it does for plain old white envelopes. You can pick the stuff up at Radio Shack if you want to try it out yourself. Just be careful not to freeze your hands when the liquid comes streaming out of the nozzle.
Mike [mmotyka@lsil.com] wrote:
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end.
Or... is there something that REACTS to freon in an interesting way...? S a n d y
Or... is there something that REACTS to freon in an interesting way...?
Freon (chloro difloromethane) is pretty inert stuff, as far as I know. According to the MSDS (Dupont: http://www.dupont.com/msds/40_37_2008fr.html), it is stable but "Incompatible with alkali or alkaline earth metals--powdered Al, Zn, Be, etc." I'm not sure what "incompatible" means here. Finely powdered Al can be pretty reactive stuff, with many things besides freon. It's a pretty good organic solvent I would think, so you could easily find some dye which would disolve in it. If it disolves easily in gasoline (or tricholormethane, even better), it would probably also disolve easily in freon, so you could test some things. In fact, a smudge of light grease in the right shape might be able to indicate that freon has been used. Maybe we should just stick with email? Anyway, how often do you think this stuff is actually used in real life? Interesting to talk about, but hardly relevant to anything, I would think. Btw, are we sure that this spray is just plain old freon? I looked around and I couldn't see any hints about the composition of this spray.
On 30 Oct 2001, at 14:51, Sandy Sandfort wrote:
Mike [mmotyka@lsil.com] wrote:
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end.
Or... is there something that REACTS to freon in an interesting way...?
S a n d y
I think freon is incredibly inert, that's why it's used. My impression is that virtually any transparent liquid will do a reasonable job of making the envelope transparent, but the considerations are that you'd want something that doesn't leave a residue and won'tr make the ink run. I believe that paper is white for the reason that snow is (as opposed to the reason that titanium oxide is), that is, you've got a bunch of surfaces where the index of refraction changes significantly from that of air and there's a chance of reflection at each surface, but the actual paper fibers are transparent. The liquid you spray on is filling in the gaps with something with an index of refraction much closer to that of the paper fibers. Pretty sure that's more or less how they work. Definately there's no chemical reaction going on. George
At 04:52 PM 10/30/01 -0800, georgemw@speakeasy.net wrote:
On 30 Oct 2001, at 14:51, Sandy Sandfort wrote:
Mike [mmotyka@lsil.com] wrote:
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end.
Or... is there something that REACTS to freon in an interesting way...?
S a n d y
I think freon is incredibly inert, that's why it's used.
Heat freon up enough, it turns into phosgene gas (as it breaks down into simpler components). The CBR types call that Blood Agent. Just think of how carbon monoxide supplants oxygen in your red blood cells, that's what phosgene gas does. I do not seem to remember the critical temperature but a lit cigarette will do it. Reese
On 30 Oct 2001, at 16:29, Reese wrote:
At 04:52 PM 10/30/01 -0800, georgemw@speakeasy.net wrote:
On 30 Oct 2001, at 14:51, Sandy Sandfort wrote:
Mike [mmotyka@lsil.com] wrote:
I would bet that there is SOMETHING that is dissolved by liquid freon. Just mark your letters with the stuff and look for the integrity of the mark at the other end.
Or... is there something that REACTS to freon in an interesting way...?
S a n d y
I think freon is incredibly inert, that's why it's used.
Heat freon up enough, it turns into phosgene gas (as it breaks down into simpler components). The CBR types call that Blood Agent. Just think of how carbon monoxide supplants oxygen in your red blood cells, that's what phosgene gas does. I do not seem to remember the critical temperature but a lit cigarette will do it.
Reese
Here's a link to the MSDS http://www.ansul.com/Material_Safety_Data_Sheets/F-85312.pdf it says above 900 F Freon will decompose into hydrochloric and hydrofluoric acids. Doesn't mention phosgene, although you'd proabably get that if the air was dry enough. George George
At 06:19 AM 10/31/01 -0800, georgemw@speakeasy.net wrote:
I think freon is incredibly inert, that's why it's used.
Heat freon up enough, it turns into phosgene gas (as it breaks down into simpler components). The CBR types call that Blood Agent. Just think of how carbon monoxide supplants oxygen in your red blood cells, that's what phosgene gas does. I do not seem to remember the critical temperature but a lit cigarette will do it.
Here's a link to the MSDS http://www.ansul.com/Material_Safety_Data_Sheets/F-85312.pdf it says above 900 F Freon will decompose into hydrochloric and hydrofluoric acids. Doesn't mention phosgene,
Try this one: http://www.vngas.com/pdf/g143.pdf
although you'd proabably get that if the air was dry enough.
How dry will the air be at the burning cherry on a cigarette? Reese
Reese asked:
How dry will the air be at the burning cherry on a cigarette?
Quite wet, because the combustion adds water vapour to the air. It won't be much good at physically wetting things, because the air is warm, but the water vapour is there and being hot will be chemically quite active. Hold a piece of cool glassware near a bunsen burner or candle flame and you will see lots of condensation. No, not *that* near... Ken Brown
At 10:06 AM 11/1/01 +0000, Ken Brown wrote:
Reese asked:
How dry will the air be at the burning cherry on a cigarette?
Quite wet, because the combustion adds water vapour to the air. It won't be much good at physically wetting things, because the air is warm, but the water vapour is there and being hot will be chemically quite active. Hold a piece of cool glassware near a bunsen burner or candle flame and you will see lots of condensation. No, not *that* near...
No, put it back in context:
Here's a link to the MSDS http://www.ansul.com/Material_Safety_Data_Sheets/F-85312.pdf it says above 900 F Freon will decompose into hydrochloric and hydrofluoric acids. Doesn't mention phosgene,
Try this one:
http://www.vngas.com/pdf/g143.pdf
although you'd proabably get that if the air was dry enough.
How dry will the air be at the burning cherry on a cigarette?
How dry will the air be, at that point where the cherry is 900 F or so? Reese
participants (8)
-
Dr. Evil -
georgemw＠speakeasy.net -
Karsten M. Self -
Ken Brown -
Matt Elliott -
mmotyka＠lsil.com -
Reese -
Sandy Sandfort