Finding an air leak using smoke

[Hobie]

I'm sure many of you are familiar with a diagnostic smoke machine for finding vacuum leaks in cars.  Has anyone tried this technique for bus air leaks?  Or better yet-- has anyone built their own smoke machine?  If so, I would sure like the details.  Cheers.

[Busted Knuckle]

Very interesting idea Fred! I hadn't thought of it until now, but what about a way to inject the air bubble solution into the air system and watching for were the bubbles start coming from? I use the bubble stuff they sell at Wal-mart for children to use for blowing bubbles. I just pour it in a spray bottle and spray it in suspected areas and watch for bubbles, but now ya got me thinking! (and it hurts! LOL!)   BK 

[Hobie]

BK.  You are already doing it right spraying the solution externally.  I think you are pullin' my leg by putting water based soap suds inside the pipe thus causing the brake line to rust.

Here is a great video showing a smoke machine in action:

http://www.redlinedetection.com/video%20page.htm

[makemineatwostroke]

Hobie, you can buy smoke in a can for a couple of bucks at any safety supply they use it to test smoke alarms and find drafts at your windows  fwiw          testproducts.com

[Green-Hornet]

Interesting. Does the method of using a soap solution work for this as well, or is the smoke thing a better way to go?

[jjrbus]

You can buy smoke at plumbing supply stores, not HD or Lowes, plumbing supply. They are used for detecting leaks and come in different sizes, measured by cu foot.   HTH Jim

[Sojourner]

Soapy water in line will squirt water but no bubble unless you wet outside of leak with pressurize air in line. Messy and waste of times as to compare to depressurize format.

Blower Door Test: (depressurize)
http://www.eere.energy.gov/consumer/your_home/energy_audits/index.cfm/mytopic=11190

I have use similar test but pressurize cars interior to find leak using water or smoking stick over weather seals as well body joints. It works quickly to locate leaks every time.
However, to check leaking spots with large bus...it better to depressurize so you can easily be with reach to smoke test any where.

A good box fan would work....just install the inlet over window's opening and taped to seal. Be sure to close all fresh air valves before testing.
Use a cigar or cigarette or purchasing a smoking pencil.

Another test is to pressurize inside with smoke but you have to re-clean the interior when done. I don't recommend it.

FWIW

Sojourn for Christ, Jerry

[HB of CJ]

I suppose it would all depend upon exactly what you are smoking?  He he he.