Homemade smoke machine for identifying vacuum leaks?

[CJ]

I have read about and also heard about a smoke machine that is used for testing vacuum leaks. It pressurizes the system with dense smoke so you can visually see the leak. Does anyone know of a way to do this at home, ie perhaps using the smoke that HVAC techs use to identify leaks in household ventilation systems and blowing that into the system? This may be a long shot, but you never know unless you ask.

[Mr. BILL]

I read in another forum that a guy made one from a coffee can. He punched a hole in the side and inserted a soldering iron that's tip rested in a small amount of transmission fluid, (the smoke).

Then he took a small air pump like the one used for tropical fish tanks and inserted a tube into the top op the lid. This created the pressure that forced the smoke out.

He then had a tube running out of the lid that would carry the smoke into the vacuum system.

I did something similar when I was a kid for a science fair project to make smoke for a wind tunnel and it worked pretty well. I used smoke pellets from a model train on a heating element. You could also use a small glass bottle with a wick poking out the top and wrap a bare wire around the wick.

It pays to watch Mr. Wizard when you are a kid.

[CJ]

Now we are getting somewhere. My concern is that I do not want to introduce anything to the vacuum lines that could cause harm to any components are the lines themselves.

[Ron Miller]

This is a great thread, or will be. I think I may have some vacuum leaks also, but my manual says to paint the hose connections with fuel and a paint brush, but I didn't want to have a can of gas and a paint brush in my hands and then go dribbling fuel everywhere. I live over 200 miles from any MB dealer, and don't know of any shop within 100 miles of me that works on MB anyway. All of these great home Hi Tech coffee can approaches are cool, and I'll bet work as good as a 300 dollar smoke machine. I'll be watching this thread with great interest to see how this gizmo developes.

[Edited by Ron Miller on 01-28-2001 at 06:01 PM]

[CJ]

I justed checked out some HVAC supply companies and they offer "canned smoke", which is safe for human contact and 100% inert. In the morning I am going to see if I can get this smoke locally. When I do, I may pump the smoke through the lines, starting at the vacuum pump itself. Let's see what others have to say.

[JCE]

Health and safety supply companies sell a respirator "smoke" fit test kit for around $50 that produces visible fumes in a small plume, but the stuff is a nasty skin and lung irritant. How about maybe placing a lit cigarette under a coffee can (well away from the car), and collecting some of the smoke from the can with a squeeze bulb turkey baster to "squirt" at the suspected leaks? Cheap enough to try, maybe.

[CJ]

Possibly a cigarette might work. My car did quit smoking cigareetes, but it still smokes diesel.

[rx-7friend]

homemade smoke machine

can be used to detect leaks in intake, exhaust, tranny, rear diff, etc.

you might be able to make one with a wet/dry vacuum, some dry ice and water, and a home made regulator. 1.) connect the vacuum hose and regulator to the vacuum on the exhaust side. 2.) put the water with the dry in a the vacuum 3.) turn on the vacuum and let the fun begin.

you could actually put a restriction on the intake side of the vacuum too.

maybe control the motor of the vacuum rpms with a potentiometer.

you could also rent a party smoke machine but i don't know if this smoke would hurt the car

more homemade smoke machine info


http://chemistry.about.com/library/weekly/aa010603a.htm


Fog Juice Recipe
WARNING: THERE HAS BEEN SOME CONCERN ABOUT THE CORRECT MIXTURE OF MATERIALS TO MAKE FOG JUICE. SINCE FOG JUICE IS READILY AVAILABLE, YOU MIGHT CONSIDER PURCHASING IT FROM A REPUTABLE SOURCE INSTEAD OF MAKING YOUR OWN IF YOU ARE CONCERNED ABOUT THE MIXTURE AND CHEMICALS USED.

WARNING: USING HOMEMADE FOG JUICE IN A COMMERCIAL FOG MACHINE COULD VOID THE WARRANTY.

ALSO: COMMERCIAL FOG JUICE IS FAIRLY INEXPENSIVE ($4 - $6 per quart at Fred Meyers and Walmart) NOW AND HAS BEEN REPORTED TO PRODUCE BETTER FOG.

You can make your own fog juice from glycerin, diethylene glycol, dipropylene glycol, propylene glycol, or triethylene glycol and distilled water. Glycerin is available at drug stores, supercenters, and home-brew stores. The others are available from chemical supply companies.

Glycerine Based Fog
You want to use the lowest ratio of glycerin to water that acheives fog for health reasons. Generally, your fog juice will be between 15% to 30% glycerin and 70% to 85% distilled water. A common lean ratio for light fog is 1 part glycerin to 8 parts distilled water. The lean recipe would then be to mix 4 ounces of glycerin in 1 quart of distilled water or 125 ml of glycerin in 1 liter of distilled water. A common rich ratio for heavy fog is 1 part glycerin to 4 parts distilled water. The rich recipe would then be to mix 8 ounces of glycerin in 1 quart of distilled water or 250 ml of glycerin in 1 liter of distilled water. When vaporized, the vapor should have a somewhat sweet smell. If it smells burnt or fowl, then the ratio of glycerin to water is too high or the temperature of the fog machine is too high.

Materials (English Units)
4 ounces Food Grade or other High Purity Glycerin ($4.00 from drug store)
1 quart (32 ounces) Distilled Water ($0.25 from grocery store)
Materials (Metric Units)
125 milliliters Glycerin
1 liter Distilled Water
Instructions
Mix the glycerin into the distilled water. Stir will. Use twice as much glycerin if you desire thick fog, but some experimentation will be necessary. If you use the leaner glycerin recipe, it will be cheaper, and and the fog will be cleaner though the fog will be lighter and not last as long.

[whunter]

for new owners