how to do a smoke screen?

[Daniel P. B. Smith]

Hello, im not sure im into the correct newsgroup, but if someone can
redirect me to proper place I would appreciate. here is my problem
im into a project, that is askin me to create smoke screen on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get the white smoke im
lookin for.
My main consideration is that, I want that smoke to be non toxic or the less
toxic possible, I tought about prestone, We all seen it smokin at a certain
point on certain car... but I am wondering if something else would give me a
great white smoke and not toxic

Also try rec.arts.theatre.stagecraft, to which I've taken the liberty of
cross-posting this message.

[Christopher Jahn]

Post by Daniel P. B. Smith

Hello, im not sure im into the correct newsgroup, but if
someone can redirect me to proper place I would
appreciate. here is my problem
im into a project, that is askin me to create smoke screen
on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get
the white smoke im lookin for.
My main consideration is that, I want that smoke to be non
toxic or the less toxic possible, I tought about prestone,
We all seen it smokin at a certain point on certain car...
but I am wondering if something else would give me a great
white smoke and not toxic

Also try rec.arts.theatre.stagecraft, to which I've taken
the liberty of cross-posting this message.

"Toxic" is fairly broad. What is non-toxic in its natural
state may cause problems when you "cook" it. That's why the
hazers used most commonly for stage atmosphere use pressure
intead of heat.

But try Mineral Oil. It's an old standby. It will certainly
smoke, but your real problem is that you will need pressure to
create any useful amount of smoke for the effect, and an
exhaust does not supply nearly enough.

[Dan Mills]

Post by Christopher Jahn
"Toxic" is fairly broad. What is non-toxic in its natural
state may cause problems when you "cook" it. That's why the
hazers used most commonly for stage atmosphere use pressure
intead of heat.
But try Mineral Oil. It's an old standby. It will certainly
smoke, but your real problem is that you will need pressure to
create any useful amount of smoke for the effect, and an
exhaust does not supply nearly enough.

I thought Sal-amonac(sp (ammonium sulphate??)) was used as a simple heat it
and you get smoke type effect, suspect it is toxic (or at least irritating)
which is why it is no longer the tool of choice.

I have heard that a dry powder fire extinguisher discharged thru a hole in
the floor of a car will discourage persuit, never needed to try it however.

The navy IIRC used to use engine oil for making smoke screens, anyone know
the details?


Regards, Dan.

[Thomas Paterson]

Post by Dan Mills
The navy IIRC used to use engine oil for making smoke screens, anyone know
the details?

Well, I overfilled my sump one day. The plumes of white smoke were ...
er ... dramatic.

A little bit of glycerine on potassium permanganate spontaneously does
the job, but it may not be the healthiest. It certainly managed to
effectively fill the Year Seven courtyard all those years ago at Lyneham
High School.

Regards,

Thomas Paterson,
LUX POPULI!

***@hotmail.com

[Thomas Paterson]

Hello, im not sure im into the correct newsgroup, but if someone can
redirect me to proper place I would appreciate. here is my problem
im into a project, that is askin me to create smoke screen on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get the white smoke im
lookin for.
My main consideration is that, I want that smoke to be non toxic or the less
toxic possible, I tought about prestone, We all seen it smokin at a certain
point on certain car... but I am wondering if something else would give me a
great white smoke and not toxic

If you can conceal a fog machine with a feed line, that would be the
best option, there are little ones (I think marketed as Goblin through
DJ shops and electronics hobby shops) which are very compact and could
be hidden with a pipe feeding to the exhaust.

They may even run off car or truck batteries!

Unless the exhaust system also need to actually work, you could feed
from the back of the muffler, well out of sight.

Regards,

Thomas Paterson,
LUX POPULI!

***@hotmail.com

[Ynot]

Hello, im not sure im into the correct newsgroup, but if someone can
redirect me to proper place I would appreciate. here is my problem
im into a project, that is askin me to create smoke screen on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get the white smoke im
lookin for.
My main consideration is that, I want that smoke to be non toxic or the less
toxic possible, I tought about prestone, We all seen it smokin at a certain
point on certain car... but I am wondering if something else would give me a
great white smoke and not toxic

Question - what is the exact situation you're in?
Are you trying for an effect ON a car, hence the exhaust heat source, or is this
in some way contrived as something else.....?
A little more info may help us to help you.

Ynot

[Eric Tellier]

OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

Eric

thx for all the replies already

Post by Ynot

Hello, im not sure im into the correct newsgroup, but if someone can
redirect me to proper place I would appreciate. here is my problem
im into a project, that is askin me to create smoke screen on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get the white smoke im
lookin for.
My main consideration is that, I want that smoke to be non toxic or the less
toxic possible, I tought about prestone, We all seen it smokin at a certain
point on certain car... but I am wondering if something else would give me a
great white smoke and not toxic

Question - what is the exact situation you're in?
Are you trying for an effect ON a car, hence the exhaust heat source, or is this
in some way contrived as something else.....?
A little more info may help us to help you.
Ynot

[Steven J. Weller]

Post by Eric Tellier
OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

There are some legal issues (vehicle codes and whatnot) but your best
bet in this stuation would be simple smoke juice for a smoke machine.
Rosco, GAM, and so on will carry it, as will the local DJ supply places
and even stores like Aahhs! (especially around Halloween).

You need to pump the liquid over the plate as a mist for it to turn into
smoke, but that's not too hard - it just has to be as fine as you'd get
from a sprtiz bottle (like Windex).

The real trick is going to be getting the plate hot enough. Truth be
told, I don't know whether just welding it to the exhaust pipe will be
enough, or not, but if it is then it should also work to just port the
spray into the pipe itself so the smoke comes out the tailpipe.
Typically, smoke machines use an electric- (or propane-) powered heating
coil that gets red-hot, and under-heated machines put out little smoke.
The juice in non-flamable but having a heat source that intense next to
where the gas tank is situated would make me a bit nervous, to say the
least.

If it were me, I'd probably buy a piece of tailpipe that matches the
pipe (muffler to the end) of the car you're using (some kind of TransAm,
IIRC?) and some sort of 12v heating element. Install that on the INSIDE
of the tailpipe, right at the end, and if possible all the way around
(line the pipe with the heating element, in other words). Then build a
metal spray nozzle, probably out of copper plumbing pipe/tubing, and
feed it through the side of the tailpipe so it can spray out and over
the elements, and weld it in place. Run that tubing up into the trunk,
attach to a windshield washer resevoir, and wire to a switch on the
dash. I'd go for two switches, one on/off with a light (for the heating
element) and one momentary-contact (for the pump). The heat of the
tailpipe will probably keep the coils nearly hot enough, but it's still
going to take a moment (at least) for the system to warm up enough to
get much smoke.

Assuming the whole thing doesn't blow up or get you arrested, it should
be a pretty cool effect.

[Scott Dorsey]

Post by Eric Tellier
OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

Purchase "fog fluid." Rosco sells it. It's usually a glycerol and water
mixture that makes a nice white smoke that hangs in the air rather than
falling.

Fog machines basically have a heated plate that they drop the stuff onto,
in very very small amounts, and with a lot of air going past in order to
blow it off as quickly as it evaporates. You may need a fan as well if
you intend on using this while the car is at idle. You may also need
something with better temperature control than just a plate welded to the
exhaust, but it's worth trying to see.

Antifreeze will do more or less the same thing, except that it'll tend to
poison people who breathe too much of it and they get stick and die. That
could really put a damper on a car show.

There are still oil-based fogging systems out there, but they are generally
messy and stinky, and it's not like the glycerol-based fluids are all that
expensive.
--scott

[Tim Mitchell]

Post by Scott Dorsey

Post by Eric Tellier
OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

Purchase "fog fluid." Rosco sells it. It's usually a glycerol and water
mixture that makes a nice white smoke that hangs in the air rather than
falling.
Fog machines basically have a heated plate that they drop the stuff onto,
in very very small amounts, and with a lot of air going past in order to
blow it off as quickly as it evaporates. You may need a fan as well if
you intend on using this while the car is at idle. You may also need
something with better temperature control than just a plate welded to the
exhaust, but it's worth trying to see.

This is incorrect, fog machines pump the fluid under pressure into a
heated chamber. The temperature and pressure used is critical to getting
a good (and non toxic) result.

You can get 12V powered smoke machines, that would be the most likely
route to success.

[Scott Dorsey]

Post by Tim Mitchell

Post by Scott Dorsey
Fog machines basically have a heated plate that they drop the stuff onto,
in very very small amounts, and with a lot of air going past in order to
blow it off as quickly as it evaporates. You may need a fan as well if
you intend on using this while the car is at idle. You may also need
something with better temperature control than just a plate welded to the
exhaust, but it's worth trying to see.

This is incorrect, fog machines pump the fluid under pressure into a
heated chamber. The temperature and pressure used is critical to getting
a good (and non toxic) result.

Yes, it's under pressure, and it also goes through a jet in order to
produce a light mist. Some of the machines use a cylinder that is
heated, while others do use a plate.

Correct pressure control is easy to obtain with a homebrew gadget. The
temperature control is what really worries me.

Post by Tim Mitchell
You can get 12V powered smoke machines, that would be the most likely
route to success.

I would tend to agree, though it could be interesting to try to homebrew
one just for amusement value.
--scott

[Clive Mitchell]

Post by Scott Dorsey
Yes, it's under pressure, and it also goes through a jet in order to
produce a light mist. Some of the machines use a cylinder that is
heated, while others do use a plate.

The plate version usually has a copper tube zig-zagged back and forth in
between two large aluminium plates that are used as a heat storage and
transfer device. The nozzle at the front is there to restrict the
output and cause an increase of pressure in the vaporisation chamber.
What comes out the nozzle is a superheated vapour that combines with
moisture in the surrounding cool air to create the fog.

[Clive Mitchell]

Post by Scott Dorsey
Fog machines basically have a heated plate that they drop the stuff onto,
in very very small amounts, and with a lot of air going past in order to
blow it off as quickly as it evaporates. You may need a fan as well if
you intend on using this while the car is at idle. You may also need
something with better temperature control than just a plate welded to the
exhaust, but it's worth trying to see.

Only the home-brew iron based haze makers for Halloween nights tended to
use this technique. The commercial units pump the liquid under pressure
into a heat exchanger with a long winding route for the fluid to
vaporise and increase in pressure as it attempts to find a way out. In
the simplest form this fluid route consists of a long length of thin
copper tubing wrapped around a powerful heating element with accurate
thermostatic control.

The antifreeze glycol is really unsuitable for smoke generation, since
it is quite toxic when used in this manner. On the other hand Glycerol
or glycerine as it is known in the catering industry is ideal for this
application, since a mix of 30% glycerine and 70% distilled water will
produce a very dense fog.

[Thomas Paterson]

Post by Eric Tellier
OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

Be very careful - most of the viable liquids, if overheated, create
toxic chemicals. Fog fluid creates acrylamide if overheated. That is
nasty stuff.

Maybe best to conceal a commercial fogger in the boot and duct out to
the exhaust pipe. A non-return flapper would let you T into the exhaust
without getting exhaust back up into the fogger.

Thomas.

[Clive Mitchell]

Post by Eric Tellier
OK, I Am building a replica of KITT, the knight rider car and im gonna use a
windshield washer pump to throw a liquid onto a plate that will be weldered
to the exhaust in order to get really hot
therefore, from the push of a button from my lowerconsole, it will create a
smoke screen effect

Hmm, well depending on the temperature of the exhaust pipe, it might be
possible to use it to vaporise standard fog fluid. The normal maximum
recommended temperature for fog fluid is about 300 degrees Centigrade,
above which the glycol will burn and produce irritants. This might not
be so critical in an outdoor situation.

If the temperature of the exhaust was high enough, then you could simply
wrap several turns of narrow copper capillary tubing round an
appropriate part, and maybe lag it with some fibreglass and foil duct
tape. To pump the fluid in, you could use a standard windscreen washer
pump.

Bear in mind that if your vehicle is tearing along the road, then the
fog will be diluted considerably with the airflow. This might not be a
bad thing!

It might also be worth pumping mineral oil into the heater tube to see
if it produces a good fog effect. Some of the older gas powered fog
machines for movie use, used oil as the smoke fluid.

[Steven J. Weller]

Post by Daniel P. B. Smith

Hello, im not sure im into the correct newsgroup, but if someone can
redirect me to proper place I would appreciate. here is my problem
im into a project, that is askin me to create smoke screen on demand.
The heat source will be a muffler exhaust.
I tought about throwing some liquid on the exhaust to get the white smoke im
lookin for.
My main consideration is that, I want that smoke to be non toxic or the less
toxic possible, I tought about prestone, We all seen it smokin at a certain
point on certain car... but I am wondering if something else would give me a
great white smoke and not toxic

Also try rec.arts.theatre.stagecraft, to which I've taken the liberty of
cross-posting this message.

Try Tri-Ess Sciences in Burbank, CA - they sell specific pyro devices
for smoke from exhaust pipes that are used for film and TV all the time,
Comes in white and assorted colors, non-toxic, easy, safe, etc.

[Madmanknot]

Just a thought..... but how about injecting fog juice into the exhaust manifold
using the piping for the smog pump?they inject air right near the exhaust
valves where the temperature is much higher than back by the mufflers....... I
must say I've taken apart several fog machines ( F-100, G-300, Gem Rosco)
before and never seen an open plate that a mist of fog juice was sprayed on...
the ones I've worked on pump the juice through a closed heater block and seemed
to use the expansion of the fog juice into a gas to drive the plume of smoke
out of the machine...never saw a fan in any of them... what model machines are
you guys talking about???