08 Dolphin/ Leaking Gray Tank

[Edouard]

This has happened twice now, we tend not to leave the Gray valve open, preferring to fill it and use it to flush after the Black waste tank. But on two occasions we have grey water dripping in the curb side end of the basement storage compartment.
I have twice removed the plastic cover on the curb side storage basement storage compartment to view the leak, there is no leak/wetness near the kitchen sink pipe, nor the vent pipe near the sink, I cannot see but there is water dripping from the botton of the boad below the tank.
Other than thinking the tank itself is cracked/ it only happens on a full tank which gives reason to believe the leak must be at or near the upper part of the tank. Any experience or idea's?
Edouard.

[Shadowcatche]

One of the ways to check for leaks (where is it coming from) is to use talcum powder, make sure everything is dry first, apply and add water. Alternatives are to use dry spray antiperspirant or find a supplier for penetrant inspection and buy developer (talc in a spray form) this can be obtained from a welding supply dealer.

[Edouard]

Quote:

Originally Posted by Shadowcatche One of the ways to check for leaks (where is it coming from) is to use talcum powder, make sure everything is dry first, apply and add water. Alternatives are to use dry spray antiperspirant or find a supplier for penetrant inspection and buy developer (talc in a spray form) this can be obtained from a welding supply dealer.

Thanks for the suggestion, but the water only appears to be coming from the underside of the tank on top of the slim plywood underbelly, curb side only, there is very little access except for the leading edges on either side of the coach, viewed by removing plastic covers in the basement compartments.

To place any talcum/etc., I would have to remove the tank which looks to be a very large flat (L) 6" thick/high by 8 feet across the coach from driver to curb side. At curb side it is approx 40" wide front to back, on the driver side 24" wide front to back.

I can see the sink drain & vent pipes, both dry, with a flashlight I can see the drain and vent pipe under/near the shower, from 6 feet away they appear to be dry. No visual wetness on 80% of the top of the tank that I can view.

Thanks again, just hoping someone has dealt with a similiar leak and may be able to shed some light.
Edouard.

[Shadowcatche]

Ed my background is in nondestructive testing and that included leak testing among many others methods. To state the obvious where the water/leak is coming from is not necessarily where it will end up and surface tension and gravity are factors in the, where it ends up. The lack of access and distances complicates matters immensely!
Talcum powder can be drifted in using a blower (hairdryer?) and the spray penetrant developer caries well (first hand experience in catching a face full).
Pressurize the system using plugs and a compressor (or water). Valtera makes a garden hose outlet that attaches to the outlet which can be adapted with a fitting for a compressor or just use water. This will open up any leak (internal pressure on the tank).

[Edouard]

Presurizing sounds like a decent idea, I do have a pancake compressor while wintering here in Fl. I suppose I would have to plug the grey tank vent's, including the one's under the kit & bath sinks, as well as all the drains, shower/sinks, and procure a fitting to apply the air at the external drain fitting. It may take a couple of weeks before I can get to an rv outlet for that fitting as we have family visiting from the north till the 14th.
But I do wan to resolve the issue, meantime I will leave the grey tank open/drain.