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wstefan20

DIY Smoke Machine for Vacuum Leaks

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I'll start by being the first to admit, this is not my idea although I may have put my personal touch on a few items. I mainly just want to share this build and hopefully help someone out along the way. If anyone is curious, just google the subject and you'll find my sources in the first few links and videos. 
 
I've been chasing a vacuum leak for weeks and no luck with water, carb cleaner, or propane (it was a small leak). Took me maybe half a minute to find the leak after hooking it up!
 
I found everything local from either harbor freight, lowes, and grocery store, other than the nichrome wire. You might find a local supplier for the wire at an e-cig shop, but it's like $5 with free shipping on ebay so I really don't see the point. Over all, I think I spent around $30, although you can certainly spend less if you already have some of the materials. The regulator was the biggest cost for me. Here's a short list of what you'll need:
 
- 1 gallon empty paint can (seriously, don't use one that's been used before, I'm not responsible for anyone dying of toxic fumes). It was around $4 at lowes.
- mineral oil (fuel for creating smoke. There's other stuff you can use, but this worked fine for me, and it doesn't stink to high heaven)
- air compressor (you'll use this to supply the air pressure)
- 3/8" or other diameter tubing of your choosing
- 3/8" barb to 1/4" npt fitting
- 1/4" npt couplers (used these as nuts)
- 1/4" npt regulator (some have used propane regulator. I used an actual valve cause it looked better, but the psi is too low to register so it's really not necessary)
- 1/4" quick connect fitting
- assorted grommets (for sealing around threads)
- assorted drill bits
- set of small machine screws, washers, and nuts
- battery clamps
- ring terminals
- tiki wick replacements
- 20Ga nichrome or kanthal wire cut and measure to 2 Ohms resistance (more will create too much smoke)
- wire (at least 20Ga)
 
You don't need to, but i soldered the wire onto both the ring terminals, and the battery clamps, and the same for the ring terminals and the nichrome. 
 
I installed a ball valve to help regulate the smoke, but quickly found it it wasn't necessary. Probably the best way is to have a switch on one of the terminals to turn the heating element on and off, but I found it wasn't necessary since it worked so quickly.
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I took two wicks and dipped downward into the mineral oil, and half of a third and used it to thicken the bundle
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Used a combo of washers and nuts to clamp everything together and seal. This is where I'm bringing the current to the heating element.
20180118_224007.jpg
This is the regulator hookup to air intake. Works well, though the gague is pointless since the flow is so low.
20180118_224017.jpg

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I wanted to test a moderate evap leak on the truck when I got it. I saw people on youtube who did something like what you have . I wanted something that was a little more handheld and mobile. I settled on using an e-cigarette vape combined with a battery powered fish tank aerator pump. Everything got power through a dc adapter, I want to say 5 volts. Both the pump and the vape are a little overdriven at the voltage, but they have lived through ~5 min of constant run time. I have burned baby oil in it and it does work. Sadly, that SES light in the truck is still there. I found countless leaks from dry rubber, but apparently not all. Or maybe the sensor is bad.

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Miller, that sounds like a fun project! Someone over at gpf said they used a cigarette lighter dc plug tire pump without the regulator and it was more mobile. Only reason I like the paint can is that it uses more current and is a higher resistance than an e-cig, so it will produce a lot more smoke, and the pump will output more to catch really small leaks, but I like the portability!

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That's a novel idea!

 

I use an F-Body one to inflate air mattresses and inflatable kayaks and they move a lot of air.

 

I'm thinking a PVC smoke chamber and pump may fit nicely into a tool box and leave enough room inside to roll up the hoses and power wires with Alligator clips to clip onto a power stud and ground.

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I use an F-Body one to inflate air mattresses and inflatable kayaks and they move a lot of air.

 

I'm thinking a PVC smoke chamber and pump may fit nicely into a tool box and leave enough room inside to roll up the hoses and power wires with Alligator clips to clip onto a power stud and ground.

I wouldn't do pcv personally. That stuff gives off terrible toxic fumes when it burns, and it will get hot. But yeah, you could definitely make a more portable container that is made out of metal or something. I almost got a quart sized paint can instead of the gallon.

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I wouldn't do pcv personally. That stuff gives off terrible toxic fumes when it burns, and it will get hot. But yeah, you could definitely make a more portable container that is made out of metal or something. I almost got a quart sized paint can instead of the gallon.

 

So the can gets warm?

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So the can gets warm?

Quite warm. Might just be the resistance I used. If you go lower the resistance, the less it'll smoke and heat up.

 

Oh, and that's actually a ball valve. Ended up not being useful since you can't put too much back pressure on the can. Best to just use the regulator knob.

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I'm not ready to build yet but maybe I'll use an ammo can I have here to hold the pump and smoke chamber and just use a quart can for a smoke chamber.

 

Then I can still store the wires and hose inside the Ammo box.

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I wouldn't do pcv personally. That stuff gives off terrible toxic fumes when it burns, and it will get hot. But yeah, you could definitely make a more portable container that is made out of metal or something. I almost got a quart sized paint can instead of the gallon.

You could maybe use a bong...it's designed to handle large volumes of smoke...

 

But that's probably a terrible idea. 

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Just watched a video where some cat made one with a quart sized can and it smoked pretty good. I was thinking maybe a windshield washer pump (universal) would move one PSI of air or so and be small enough to make that a very portable smoker.

 

Edit: Wait it's 1 PSI? Maybe a 12V computer fan glued to a funnel, that's like nothing. There are small pumps 2/ $8 on Amazon that do 350 mmHG which is 6.76 PSI.

Edited by Imp558

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Actually that pump would probably be pretty close anyway, it's like a 1/4" outlet. Nice that there's 2 for that price because to make 1 - 2 PSI in the chamber it may actually take both.

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Excellent build and post wstefan20! A word of advice/ caution to anyone using these: if using to find leaks in the EVAP system, be extremely careful or avoid using compressed/ ambient air to check, as inducing air (oxygen) into the evap system has the potential for creating a bomb. Optimally, one should use an inert gas (CO2 or Nitrogen) if possible.

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Excellent build and post wstefan20! A word of advice/ caution to anyone using these: if using to find leaks in the EVAP system, be extremely careful or avoid using compressed/ ambient air to check, as inducing air (oxygen) into the evap system has the potential for creating a bomb. Optimally, one should use an inert gas (CO2 or Nitrogen) if possible.

Thanks!Good to know! Evap Valve should be shut when off when engine is of right?

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Ideally, unless it's broke. It's common to smoke the evap and gas tank looking for leaks underneath so that's probably what he was referring to. Would probably want to have a little airflow before starting the coil so gas vapors don't travel back into a burning smoker.

The commercial ones use air but I get what he means about inert gas. Have to wonder if the wick would start going without air though.

Edited by Imp558

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