I saw several of these home-made smoke/fog generators on the interweb and decided on a lark to put one together from stuff I mostly had on hand.

Very simple, composed of a glass mason jar, 30w soldering iron, valve stem, hose, and bicycle pump.
Fluid used was initially some generic mineral oil. I also added a splash of fog juice I found at a resale shop for 99 cents.



I changed the lid of the mason jar a bit, rather than the thin metal center cap I made a 1/6" thick replacement for more rigidity. Enabled me to weld in a bit of brake tubing to attach the plastic tubing onto.
I also drilled a hole for the tire valve and the soldering iron. The iron was attached with jb weld.

First test with mineral oil saturating a cotton sock - I was very pleasantly surprised with the good dense smoke. The bike pump allows you to pressurize the jar and whatever you are testing with low pressure. The saturated cotton acts like a wick for the hot soldering iron, no flame, just smoke.
The pics below are only after about 5 minutes, beyond that the smoke got a bit thicker.



A little pump pressure yielded a good stream of smoke.



I used it to check truck 5.3 intake and it worked great. I added a bit of the fog juice and was really getting dense smoke. Very easy, just plugged up the snorkel and stuck the hose inside.
Intake checked out fine, as a test I also pulled a rear vacuum line and there was plenty of smoke coming out so I know it was saturated well. The bike pump makes things very controllable.



One important note - the glass jar gets hot so be careful. Since this use I've usually placed the jar into a metal can just in case the glass cracks - I can see why the commercial versions are in metal containers, or also why other diy use a paint can.

Pretty good addition to any low-budget tool collection!

 

A smoke generator is a GREAT tool to have. Makes finding leakage problems SO MUCH EASIER to find. Thanks for sharing your homemade tool.

 

Man, you never cease to amaze me with your ingenuity. So we can't use a Hookah pipe?

 

Key08, I guess it's like a big vape thingy lol.
Sunnyslope, you are spot on, took like 15 min to do the check on the entire intake system!

 

I tried a similar setup but with some of those unscented incense sticks. It worked, but the smoke wasn't very thick so it was tough to see where it was coming out. Just remember not to bump up the air pressure too much or you'll start getting false positives!

 

Darn and all those years I was advising spending the money on

 

Lol, I wish I knew something about those - all I know is they make a lot of smoke