Best air gas leak detection fluid

Mix standard dishwashing liquid "soap" in the protective cap off a spray can, about 1 part soap to 5 - 10 parts water, and dab it around suspect spots with your finger. $20 a bottle is VERY funny, because there's about 5 cents of stuff in it, not counting the bottle itself.

Jon

The reasons I've seen for not using just an ordinary dishwashing detergent dituted are that they contain chemicals which are corrosive to brass alloys often used in gas connection components. Best to get a proper leak check spray in my opinion but $20 seems to be taking the piss, proper stuff is available much cheaper but can't help with the US as I'm in the UK.

David Billington fired this volley in news:527423f3$0$1167$ snipped-for-privacy@news.zen.co.uk:

Sodium lauryl sulfate with a TINY bit of acid added (citric, usually) is a pH-neutral, non-corrosive 'sudser'. Most 'gentle' shampoos are exactly that. (WITH the acid added to neutralize the basic character of the sodium/olive oil salt).

Johnson's Baby Shampoo "no tears formula" comes to mind.

Lloyd

Grainger: NuCalgon fluorescent gas leak detector, 8 Oz dauber bottle, $8.78 3CFR3 Convenient for small things like a suspect fitting.

Johnstone has several choices, see what's in stock at your local supplier (or any Heating and Air supplier) - they have the NuCalgon Fluorescent 8-ounce dauber bottle above, a Quart spray bottle, and gallons of it. And the same basic thing from SUPCO, and Refrigeration Technologies "Brush-on Blu"

or the NuCalgon Cal-Blu Plus (+5 F to +220 F) in both 8-ounce dauber, Quarts with a spray top, or gallons.

Refrigeration Technologies Super Blu (-30 F to {220 F?}) in both Quarts with a spray top, or gallons. And a few other suppliers make the same basic stuff.

Depending on the size of the leak and what you're looking for, there are other choices of the Electronic Gadget persuasion - Ultrasonic leak detection, Combustible Gas detector, several variations on Refrigerant leak detectors...

No consumables, no mess - unless you need to use a little liquid soap to confirm exactly where the electronic detector is triggering. And you don't need to slop it all over.

Having Both on hand is best, along with Ultraviolet Dye Injection and a hand-held blacklight solutions. The dye injection will find tiny leaks the other methods might miss, because it leaves a visible track over time.

jsw

"Jim Wilkins" fired this volley in news:l52me9$66a$1 @dont-email.me:

Was that just an interesting tidbit to confirm what I said, or for some other purpose?

Ammonia (actually ammonium hydroxide, in the form that attacked the brass) is basic (high pH). Using an ammonium-based detergent would be bad for two reasons.

1) ammon-salts of fatty acids are even higher in pH than sodium salts are

-- more corrosive

2) neutralizing something made basic by ammonia usually results in the release of some corrosive gas... ammonia, chlorine.

Sodium lauryl (or laureth) sulfate is an almost-neutral sodium ether of fatty acids, requiring little additional acid to bring it to neutral. Adding citric acid to it does not release harmful, corrosive gasses.

(BTW... I said "olive oil" earlier. That's how SLS got its name originally, but it can be derived from almost any vegetable oil... coconut being popular these days)

More to the point... if you use neutralized SLS (like baby shampoo) to make some leak detector, you're NOT going to get any copper corrosion as a result of using it.

Lloyd

Lloyd

So don't store your ammo in the horse pizzouse?

I'm curious which relationships I can assume people will grasp, and which I have to beat into their skulls. Often I find that I expected too much. .

Notice that Caustic Soda rates a B despite its extremely high pH. A component of the D substances forms a stable complex with copper ions, which requires that they be oxidized and usually damp. Ammonia is A when dry, D when damp.

Sorry, I didn't find a chemistry-for-dummies version of this:

"Virtually all biochemicals exhibit the ability to dissolve certain metal cations."

That's the reason soda and coffee can strip the rust off steel.

jsw

Kano Labs "Bubleak" works every time for me.

hth

Bob rgentryatozdotnet

I've seen PLENTY of corrosion where commercial leak spotter stuff has been used. So, while this CAN be a problem, I do not believe any of the commercial stuff is any better in this regard.

Jon

Kind of depends on your criteria. Best as in low cost? Best is in shows small leaks? Best is in does not cause corrosion? Best as in easily procu red?

Most of the time I am looking for leaks it is in tires, so corrosion is not a criteria. I use Dawn liquid detergent because it is the most easily pro cured. There is a bottle of it under the sink in the kitchen. Back in the 1960's there used to be a mil spec for hermetically sealed electronics th at was known as the Joy test. It used Joy detergent, so I suspect Joy dete rgent is somewhat better than Dawn for detecting leaks.

Where I used to work they used Helium. Better than air because it is a sma ller molecule. And of course they used a helium leak detector. So best as far as small leaks, does not cause corrosion, and is not hard to procure. But certainly not the cheapest.

Dan

So what mixture ratio is generally used with liquid detergent on say natural gas and air - half and half?

I do not measure, but would guess I use about 1 part detergent to 30 parts of water.

The following is from a site that is about making soap bubbles for fun , no t for detecting leakl.

Here at the Exploratorium, we've found the bubble formula below to work fai rly well in our exhibits.

• 2/3 cup Dawn dishwashing soap * 1 gallon water * 2 to 3 tablespoons of glycerine (available at the pharmacy or chemica l supply house.)

New formula!

From "Marcia" in Canada I got the following formula which works for her:

• 1 cup Ultra Ivory Blue * 12 cups water * 3/4 Tablespoon glycerine

Gently stir the ingredients together and leave the solution in an open cont ainer overnight. We believe that this gives the alcohol on the dishwashing soap a chance to evaporate some. In any case, the solution seems to get bet ter with age. If you substitute some other soap for Dawn, you will have to experiment with the rest of the formula... but that's the fun of science!

Dan

I use Windex glass cleaner, it will wet the surface & bubble up nicely on a leak & evaporates quickly, does not leave a sticky residue on stuff like any soap would. Plus I always have it on hand.

MikeB

Wow, I just grab a bottle of bubble juice from the dollar store.... The stuff that you use the wand to create bubbles.

For the tire tank I use washer fluid with a couple bottles of bubble juice. Works good and doesn't freeze (Stays outside so it doesn't get dumped)

No, not more than 1:10 soap/water should make nice bubbles. Too much soap makes it necessary to clean up afterward. I use the same solution for air leaks, both vacuum and pressure.

FWIW, the makers of a toy that came out 30 or so years ago for blowing giant bubbles recommended Joy as the best.

So, you watch *inside* the pipe for bubbles? :-)

Right, one climbs inside the vacuum and... ;) No, it makes a giant slurping sound as it's absorbed by the hole; very noisy. I used it mainly on automotive engines, dashboard accessories, vacuum motors, and hoses.