Can't find the leak in my tank

[rickryder]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

jb weld doesn't work on gas

Really?? You may want to read the list of uses on the package........http://jbweld.net/products/uses.php

 

[RogersJetboat454]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

OK....

So the JB was strictly to fill in cosmetic dimples that didn't actually punch through? For all we know these dimples may have been present since day 1 when the tank was initially installed.

I would say use it. Loosing 2 lbs out of 5 overnight isn't exactly the leak that brought down the Titanic. Keep in mind, your fuel tank wasn't built to be a pressure vessel. Microscopic leaks around seams, welds, and seals may be present and acceptable. If this tank was installed in a modern car which actively checks the fuel system for evaporative leaks, this tank would most likely pass. More food for thought; fuel and fuel vapor is thicker than air. Meaning a microscopic leak that may pass air may not necessarily pass fuel/vapor, especially considering the fuel/vapor is theoretically not under pressure.

 

[Fed]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

I suppose it's feasible to lose 2Lbs overnight due to the temperature drop.

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Temp drop? How does that work? it's sitting in my basement...

Also, I'm 100 % confident with the JB welding...

The dimples weren't cosmetic... they didn't puncture the tank, but they could have if it got corroded or something..

 

[scipper77]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

I suppose it's feasible to lose 2Lbs overnight due to the temperature drop.

Temp drop, or maybe the walls of the tank are relaxing a bit?? the difference between 3 and 5 lbs really isn't that much in terms of forces the tank sees. I would want to try 15 lbs.

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

That wouldn't be dangerous to the tank? I tried 10 yesterday and found it at 7-8 24 hrs later...

 

[scipper77]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

That wouldn't be dangerous to the tank? I tried 10 yesterday and found it at 7-8 24 hrs later...

Let it go for another 8 hours and see where you are at. what are you using for a valve/shut off after you pressurize the tank?

 

[Fed]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

I wouldn't pump it up anywhere near even 10 Lbs, I think there's a standard for the test of only 2 or 3 Lbs.
15 PSI over the surface area of the tank is a lot.

 

[Fed]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Temp drop? How does that work? it's sitting in my basement...

If your basement is at a constant temp then it doesn't work but if the temp goes up & down then the pressure in the tank will rise & fall accordingly.

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Yeah I think 10 was even pushing it... The pressure tester has a 1 way valve in it, I'm just using that. SHould I put a cap ove rthe back of the tester on the bike pump side? I was prettu sure that was a 1 way valve..

 

[NYBo]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Here are standards manufacturers must meet in regard to fuel tank testing:

FEDERAL LAW

183.542 - Fuel systems

(a) Each fuel system in a boat must have been tested by the boat manufacturer and not leak when subjected to the greater of the following pressures:

(1) Three pounds per square inch; or
(2) One and one-half times the pressure created in the lowest part of the fuel system when it is filled to the level of overflow with fuel.

(b) The test pressure shall be obtained with air or inert gas.

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

So it seems like mine is passing...?

 

[rickryder]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

System Pressure Test: The entire fuel system must be pressure tested to insure there are no leaks. You have to test the system at least at three PSI, unless you have a long deep system. Then it must be 1 ? times the greatest pressure in the lowest part of the system. For most boats three PSI will do.

http://newboatbuilders.com/pages/fuel.html

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Should I retest it at 3 psi and see if it holds that?

 

[rickryder]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Yes

 

[zopperman]

Re: Can't find the lak in my tank

Re: Can't find the lak in my tank

Just an update for anyoen else following this thread (rick already knwos what happened...) The tank seemed to hold 3 psi for about 15 hours So I secured it in the boat with some CSM coated pieces of wood and put it up on feet so that the aluminum won't corrode if exposed to water. Also drileld a drain hole underneath it. Put 6 gals of gas in it and it's not leaking, the sending unit works, and the primer bulb works too