I used 20 gauge. 30 ga. will probably work but you will need to change the length if you use it. I believe you will need a longer piece.

I tried to do the math required for determining the proper length in my head and had a brain spasm.

There are charts to determine the resistance per length or you could just use the ohm meter.

Yup, used it to find a leak around the injector seals on my M117.

I use an adjustable pressure regulator from my spray gun to control the pressure. 2 P.S.I. maximum. It gives you a bit of a thrill when the lid pops off the can while it's over-pressurized!

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

30 awg is smaller in diameter than 20 awg, that means 30 awg has higher resistance per foot than 20 awg. 30 awg would have to be shorter in length to be the same resistance as 20 awg (to draw the same current). An easy way is use an ammeter in series with the battery and the Nichrome wire and use an alligator clip and just move it along the other end of the Nichrome wire till the ammeter reads the amps (thus power) you want. With the amps measured, you can calculate the power with ohms law.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Do you have a video of it? What did you use for a container? I am going to use a mason jar so I can see everything in action. Would be kinda cool.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I believe I pointed out that trying to do the math in my head caused a brain spasm.

I bought a gallon metal paint bucket. It was about $5.00. Glass containers have never had a very long life span around me.

I went with metal because it is a more secure way to mount the terminals and the air coupler.

I'd post up a picture but it's no different than what any of the others have done as seen on YouTube.

One thing I found out was that lamp nuts are 1/4" pipe thread and work well to lock the air inlet. Got them at the hardware store for about $0.50.

Used some 12 Ga. wire for leads. Probably could have used 14 or 16 but 12 is what I had handy.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

Here is a good site _NiChromeData on Nichrome wire. The glass jar if for development purposes to get the best smoke, after which you can go to a metal container. Looks like with 20 awg 23 ft long you are drawing 0.8 amps = 9.8 watts. Have you measured the current?

Did you experiment with different wick materials such as cotton vs synthetic? Orientation of the wick (horizontal vs vertical)?

I can't find my roll of Nichrome wire so will start with my experiments using a 12 V cig. lighter, soldering iron, clothes iron, hair dryer and whatever other junk stuff with Nichrome in it that I have laying around.

Are you getting good smoke with yours? How does it compare to a commercial unit? How about a pic of it working?

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Umm, 23 FEET long? I don't think so. Try 23 INCHES long.

Using NiChrome 80 20 GA.

.6348 ohms per foot. .6348/12 (IN per Foot) = .0529 ohms per inch. 23 IN. X .0529 = 1.12 ohms total resistance.

https://www.temcoindustrial.com/product-guides/wire-cable-and-accessories/resistance-and-non-resistance-wire/nichrome-wire.html

Tried a couple of different materials (paper, rags, cloth rope) but the Tiki wick seems to be the best choice. The cloth rope was close but the Tiki wick has an interwoven structure which adds integrity to it. Paper and rags don't seem to wick fast enough to keep up with the smoke.

Went with horizontal since I mounted the leads on opposite sides of the can.

Getting a plentiful amount of smoke using mineral oil. Definitely on par with any commercial, un-powered smoke machine I've ever seen.

Smoke doesn't photograph well without doing some fancy lighting or background tricks.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

OK 23 inches, that's more reasonable, which would make it closer to a glow plug wattage.

Is your Nichrome wire getting red hot or not?

What do you mean by "commercial, un-powered smoke machine"?

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Yup, gets red, glowing hot at 11.7-13.7 V. Get's WHITE, smoking, "Holy crap, what's that smell?" hot above 14.5 V.

The large commercial machines used for industrial testing of big evaporators, condensors, air transference, etc. have their own power source and air supply (usually in the form of an inert gas generator or storage tank). They usually don't use mineral oil or a petroleum compound for smoke but the theory is the same.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

Do you know what they use instead of mineral oil? Do you know if mineral oil smoke is safe for Oxygen sensors or other sensors in a modern vehicle? I see these DIY's on youtube using a cigar or a rag soaked in oil lit with a match as the smoke generator and wonder. The tar from the cigar can't be good.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Graham is right. A smoke pro is good for intake manifold leaks or evap leaks. A mightyvac will never tell you if your intake gaskets are compromised, nor will it tell you if you have a tiny .020" or .010" evap leak. If your testing a fuel tank, dont use shop air. You will take a saturated fuel vapor enviornment, and introduce a good friend of fire....oxygen. Then all it takes is a static electrical spark, then its night night for you. BOOM. Use nitrogen.....

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2011 Mercedes ML350

2002 Cadillac Deville

1976 Rolls Royce Silver Shadow

I build my smoke machine with glow plug and I use baby oil.

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English second language.

X2 on the baby oil. Cheap and very effective. Do a google search, youll see that most smoke pro users fill with baby oil. The smoke pro unit is even supllied new with simple mineral oil.

__________________
2011 Mercedes ML350

2002 Cadillac Deville

1976 Rolls Royce Silver Shadow

Anyone who built their own incorporated a flow meter and a pressure gauge? What kind of smoke pressure are you getting? The commercial units are around 0.5 psi

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Most EVAP systems have a max pressure of 1psi. The smoke pro incorporates a tiny ball that floats in a gauge. 0-1psi. I usually run at .5 like your were saying.
Most EVAP systems have sensitive flow sensors, solenoids, and pressure sensors. If you pump in 20psi, youll send those expensive parts to an early grave.
When smoke testing, high psi is not needed. Your just looking for a small whisp of smoke.

__________________
2011 Mercedes ML350

2002 Cadillac Deville

1976 Rolls Royce Silver Shadow

Smoker with lid off, power disconnected


Inside of smoker showing the coil and wick. Those strands sticking out are from the wick.


Tried to get a view of the coil glowing but failed. Gives you an idea of how much smoke it creates though.


Top view of the smoke.


Smoke using apx. 1 PSI.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now