Gas sniffer beeps but no bubbles showing

[action95]

Hi all, I just hooked up all the gas lines on my renovated 1972 overlander. I’m not getting any bubbles when I spray the connections, but when I use the gas detector I bought I’m getting a reading of detecting gas. Does anyone know if it’s normal to get some residual fumes at the connections that would make the gas sniffer go off or should there be absolutely zero readind? Thanks for any info!

[BayouBiker]

There should be no gas detected. Does the detector go off randomly away from gas fittings?
If not there are likely small leaks. What are you using for the soap test? If you're not using a soap formulated for leaks it may not have enough surface tension.

[ROBERT CROSS]

Another of my dumb questions.
Is it a LP detector?

Bob
🇺🇸

[action95]

Thank you for your replies. It is just dish soap, so that may be the problem. The detector had several gases listed that it will detect

[action95]

No, it was not going off randomly, and I have to keep it there for a few seconds before it will start going off. It seems to be coming out where the female fitting goes on to the gas pipe, not where the male and female connect, if that makes sense.

[BayouBiker]

You can get the gas leak soap from amazon or at Home Depot, but you may want to remake the the suspected fitting. if they are pipe threads, you'll want teflon tape on it. If it is flare or knurled tubing, take it apart, clean the mating surface and inspect for damage, scratches, pitting or gouges. Good luck.

[jaybauman]

Originally Posted by BayouBiker

You can get the gas leak soap from amazon or at Home Depot, but you may want to remake the the suspected fitting. if they are pipe threads, you'll want teflon tape on it. If it is flare or knurled tubing, take it apart, clean the mating surface and inspect for damage, scratches, pitting or gouges. Good luck.

And if it's NOT pipe threads, by no means should you use teflon tape.

[rwnash]

The gas detectors can be very sensitive - which is a good thing. I have had good luck on threaded fittings using a blue colored pipe dope (Mega Block?); if you need the brand name let me know and I'll see if I can find the can in the shop. As far as teflon tape goes, I think they make a special yellow tape for gas. But I gave up on teflon, the blue pipe dope works better.

Good luck, Whit Nash

[uncle_bob]

Hi

The detector is doing exactly what you bought it to do. It's spotting a leak that would be hard to find by other means. It just paid for it's self

Easy answer normally is to rebuild any joint(s) it does not seem to like. You can play with bubble stuff, but some leaks are hard to find that way.

When you pull this or that joint apart, check ( = examine visually ) both fittings. That may be hard to do, but if one is damaged / defective (it does happen ...) you will go around in a lot of circles rebuilding stuff. Same thing applies to the hose and pipe ends themselves. A crack there isn't going to be fixed by some more tape ....

Fun !!

Bob

[Kawboy01]

If you do use Teflon tape make sure it's rated for gas service and not water or liquids.

[greghoro]

Originally Posted by Kawboy01

If you do use Teflon tape make sure it's rated for gas service and not water or liquids.

Yellow Teflon tape, not the more common white stuff.


Greg

[BayouBiker]

The Gas tape is just thicker so it seals a bit better. You can get the same effect if you quadruple wrap the white stuff if you're not able to find the yellow grade.

[rmkrum]

Time out. That’s a shortcut to a propane leak that won’t seal up properly.

The white stuff, no matter how many wraps you put on will not seal propane. It’s just not dense enough. Propane molecules are just too small. I’ve tried that, and gave up. The big box stores carry yellow Teflon, as do most Ace hardware stores.

If you can’t find yellow Teflon, use a propane-rated pipe dope stick carefully. Don’t let it smear inside the fittings.

[ROBERT CROSS]

My experience, I have used white to seal all threads, all applications, wrapping clockwise, tightening carefully and never had a failure.
The only difference is the thickness & $$$$.🤔

Disclaimer...I noe nothing.
Bob
🇺🇸

[action95]

I appreciate all the responses here. Thanks for the help

[BayouBiker]

I will say the yellow gas tape is also a bit more dense coming off the roll than the white tape because the white tape is stretched in the manufacturing process. Again if you overwrap it, the density will increase as it is compressed into the thread gaps. Sure the yellow stuff produces a more reliable seal so it is preferred if you have it.