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wstefan20

DIY Smoke Machine for Vacuum Leaks

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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.

 

Ah, I see what he's getting at now! Yeah... that would not be good! Good news about the heater though is it doesn't actually use a flame, the wire just gets really hot, though not sure if it gets hot enough to ignite fuel... I don't want to test that one... lol. Definitely wouldn't try this on evap leaks without serious modification.

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I'd think as long as you have a little air movement it would be safe. Maybe check on some forums where diy smokers are made and see what the consensus there is first.

 

Yeah, and I'd feel better throwing in a check valve too, but should be "fairly safe".

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Drawing fuel vapors back into the canister with that small of a hose wouldn't be my concern.

 

The real concern is pressurizing the fuel tank with ambient air. I believe that's what he means by "creating a bomb". That mixture would only need an ignition source and boom. Realistically though, that ignition source is hard to come by. You introduce some amount of ambient air into the gas tank at every fill up. Fuel pumps are spark proof, for obvious reasons. So I have a hard time seeing the problem, especially since that ambient air gets burnt once the engine is running. The only real concern is a big enough leak to lead into the gas tank combined with someone smoking while completing the diagnosis.

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Drawing fuel vapors back into the canister with that small of a hose wouldn't be my concern.

 

The real concern is pressurizing the fuel tank with ambient air. I believe that's what he means by "creating a bomb". That mixture would only need an ignition source and boom. Realistically though, that ignition source is hard to come by. You introduce some amount of ambient air into the gas tank at every fill up. Fuel pumps are spark proof, for obvious reasons. So I have a hard time seeing the problem, especially since that ambient air gets burnt once the engine is running. The only real concern is a big enough leak to lead into the gas tank combined with someone smoking while completing the diagnosis.

Ok. Makes sense. Thanks! You'd need oxygen for the smoke I'm guessing though. Otherwise you could use nitrogen

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Figured I'd be nice to post a video of it in action. As a preface, in the video I had already turned off the smoke and it had been running for a while so the actual max smoke output is 10 times more than what the video shows.

 

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Drawing fuel vapors back into the canister with that small of a hose wouldn't be my concern.

 

The real concern is pressurizing the fuel tank with ambient air. I believe that's what he means by "creating a bomb". That mixture would only need an ignition source and boom. Realistically though, that ignition source is hard to come by. You introduce some amount of ambient air into the gas tank at every fill up. Fuel pumps are spark proof, for obvious reasons. So I have a hard time seeing the problem, especially since that ambient air gets burnt once the engine is running. The only real concern is a big enough leak to lead into the gas tank combined with someone smoking while completing the diagnosis.

I don't know why I said ambient air. I really just meant compressed air, which does present a hazard.

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Yeah. I figured out a "safer" way. The volume of smoke is so great that you can hook it up and burn for a few seconds and then hook up to the system with no burning and blow smoke into the system. The best way would be to have a standby tank that you could pump the smoke into to completely separate the risk of ignition.

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Unless you change the air that you're pumping into the system, the risk in question is not changing. Whether you create the smoke right away or put it away for days, it does not change the fact that you are using air from an air compressor to flow that smoke. Since the air compressor uses ambient air as its intake, you are creating a possibly ignitable mixture in your gas tank. All it needs is an ignition source, and it could be explosive. Again, unless you have someone smoking at the gas cap, I don't see it happening easily, but it still a safety risk. To mitigate this, an inert gas, such as Argon, could be used to flow the smoke. Again, I'm not so sure how much smoke would be created in an Argon environment. I have a feeling it does not change, since no flame is needed.

Edited by vipmiller803

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Unless you change the air that you're pumping into the system, the risk in question is not changing. Whether you create the smoke right away or put it away for days, it does not change the fact that you are using air from an air compressor to flow that smoke. Since the air compressor uses ambient air as its intake, you are creating a possibly ignitable mixture in your gas tank. All it needs is an ignition source, and it could be explosive. Again, unless you have someone smoking at the gas cap, I don't see it happening easily, but it still a safety risk. To mitigate this, an inert gas, such as Argon, could be used to flow the smoke. Again, I'm not so sure how much smoke would be created in an Argon environment. I have a feeling it does not change, since no flame is needed.

Agreed. Though the smoke is caused by combustion despite no visible flame, so by separating the ignition source, it would be safer. Not by much I agree, but it would work in a pinch. Problem is, all real smoke I've seen is a byproduct of burning, so argon or other inert gas is out of the question unfortunately. I'm sure there's a good method that is safe but I doubt it's diy

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I think the amount of air is relatively small considering this is 1-2 PSI. Also every gas tank with a rotten evap hose, bad gas cap, leaky seal is an equivalent danger by this standard. A tank with a leaky fill hose and a working evap is drawing in atmosphere every time the evap solenoid opens and begins a vacuum. Too much worry over too little risk. Even having the burner and airflow on any gas vapor would be pushed back away from the ignition source.

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Too much worry over too little risk.

Agreed, as long as the person doing the diagnosing keeps any ignition sources away. 1-2psi in a 17 gallon tank with little fuel in it can be very bad if a cigarette is lit at the leak.

 

 

Agreed. Though the smoke is caused by combustion despite no visible flame, so by separating the ignition source, it would be safer. Not by much I agree, but it would work in a pinch. Problem is, all real smoke I've seen is a byproduct of burning, so argon or other inert gas is out of the question unfortunately. I'm sure there's a good method that is safe but I doubt it's diy

Are we sure this is combustion? I think we're just vaporizing the baby oil, which has mineral oil as its main ingredient, which is what the "smoke" is. In that case, no combustion. Smoke may be a product of combustion, but not all visible gases are.

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Agreed, as long as the person doing the diagnosing keeps any ignition sources away. 1-2psi in a 17 gallon tank with little fuel in it can be very bad if a cigarette is lit at the leak.

 

 

Are we sure this is combustion? I think we're just vaporizing the baby oil, which has mineral oil as its main ingredient, which is what the "smoke" is. In that case, no combustion. Smoke may be a product of combustion, but not all visible gases are.

Hm... maybe that was just a fluke then? I accidentally had the flow blocked and the gas ignited and blew the top off the can and everything was on fire. Could be because the air was so compressed though.... lol Luckily it was contained in the can, but it did scare me half to death!  :smilielol:

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Hm... maybe that was just a fluke then? I accidentally had the flow blocked and the gas ignited and blew the top off the can and everything was on fire. Could be because the air was so compressed though.... lol Luckily it was contained in the can, but it did scare me half to death!  :smilielol:

If you had little enough fluid in there, your element probably reached the flashpoint of the mineral oil. ~335F.

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If you had little enough fluid in there, your element probably reached the flashpoint of the mineral oil. ~335F.

I think you're right. That heating element gets really hot! Plus doesn't compressing gas decrease the flashpoint temp?

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I don't know about that but I know compression is the difference between my potato cannon going "pitooey" and going "BANG".

 

Another thing to consider here is that this thread isn't exactly pioneering, just bringing it here. There are plenty of these things in use and more being made each day. Smoking an EVAP I thought meant the connection was all the way at the EVAP solenoid so one could inspect the whole system? If that's the case it's pretty far from the tank as well.

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lol this would be the ultimate option for evap, but no... I'm not about to drop that kind of money. I'd rather use my redneck way and blow **** up! haha

 

Edit: I must preface that I bought my car for $200 so that might have something to do with it....  :smilielol:

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hahahahhahaha this just made my day! 

 

https://www.ebay.com/itm/EVAP-Smoke-Machine-Diagnostic-Emissions-Vacuum-Leak-Detection-Tester-NEW-/301673812635

 

I can't believe that someone has sold over 2000 of these!!! I made one with better quality for like $20! What a crock! Maybe I'm in the wrong business!

 

But this adapter I might have to buy... 

 

https://www.ebay.com/itm/EVAP-Service-Port-Adapter-Connector-Kit-w-Valve-Removal-Tool-Smoke-Leak-Tester/272719071249?epid=28003284213&hash=item3f7f52c811:m:m_kA993wTbrjvvakQ1jizzQ

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I can't believe that someone has sold over 2000 of these!!! I made one with better quality for like $20! What a crock! Maybe I'm in the wrong business!

 

What a Dick, hard to believe people are so stupid.

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So I built myself one of these.

 

Did a few things different, i'll probably have to revise things. I only used one tiki wick and I used Vegetable Glycerin rather then mineral oil.

 

Not getting as much smoke as I would like. May change to Mineral oil or baby oil

 

I also used an airtool regulator. I may change that to a propane regulator as its way too easy to over pressurize the container

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So I built myself one of these.

 

Did a few things different, i'll probably have to revise things. I only used one tiki wick and I used Vegetable Glycerin rather then mineral oil.

 

Not getting as much smoke as I would like. May change to Mineral oil or baby oil

 

I also used an airtool regulator. I may change that to a propane regulator as its way too easy to over pressurize the container

I came across the same observations and I agree, I'll have to put a note in the guide when I switch to the propane regulator. I think air tool would be great if you use a different container like a pressure cooker or something. And yes, mineral oil works waaay better. You can find it at any cvs or Walgreens. Good luck!

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I just looked through your initial write up again. I used 22ga wire - was the thickest the vape shop had. I wonder if that's part of the reason

As long as you have the same resistance, it should preform the same from what I can tell. You can always make it with longer wire to get more smoke!

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