RV12iS Fuel Tank Leak Test

Hello. I am going to leak test my recently built RV12iS fuel tank. I have seen other references in the past that mention leaving the unit sealed with air for 24 hours and then verify that the balloon does not lose too much air. It seems like a good idea but I don?t see any reference to the 24 hour wait period in the Fuel Tank Pressure Testing instructions. It just mentions checking the tank with soapy water and looking for bubbles.
Was the 24 hour waiting period something that was used in older instructions?
Thanks.

A 24 hour test is not necessary. The pressure will fluctuate as atmospheric pressure changes over time. That change might lead one to believe there is a leak when there is none.

Mich48041 said:

A 24 hour test is not necessary. The pressure will fluctuate as atmospheric pressure changes over time. That change might lead one to believe there is a leak when there is none.

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Which is why the KAI recommends a procedure of using a soap bubble test.
If you already have the tank slightly pressurized anyway, it takes only a small additional effort to brush a soap solution over all the joints.
A lot of people just put it in the bath tub and then rinse it off well when done.

After 7 years my tank is still tight. I did the soapy bubble test on all the seams and fittings. Drop tests are Ok, but to my thinking all they do is tell you if something is leaking: no indication of what or where, so you might as well just do the soapy bubble test. Remember the leak in a drop test might be in your test rig or it?s fittings.

At the time I put the tank together and saw those big holes at the corners I thought there is no way this sealer will make this leak tight. Fortunately I was epically Wrong!

I did the soap test.. no signs of leaks.

I made the mistake of letting my Dove soap dry without rinsing it off (it was summer, it dried on its own [aka. i forgot]).

Not sure if it was something in the detergent or if the spray bottle was contaminated with something, but the entire tank showed signs of surface corrosion after a few months. I took a sander to the tank (until i could no longer see where the corrosion was).. I'm sure most of the Alclad is gone. I sprayed with primer. And the carpet will cover almost all it anyway.

Rinse your tank when finished!.