REFLECTOR: Fuel Leak

[Brian Michalk]

I think you should to a tank pressure test for a few days first.  Then 
try to repair at the source of the leak.  I have a pesky pool of oil in 
a small area from a spill years ago that I just can't get rid of.  It 
can travel a long way from the initial point of the leak.  So even if 
you patch up where it's coming out now, it will sure enough find another 
place to come out later.

On 1/31/2011 10:43 AM, Scott Derrick wrote:
> I think I have a dreaded fuel tank leak!
>
> I calibrated my fuel sensors yesterday, which involves removing the 10 
> gallons I had on board and then filling the tanks in 2 gallon 
> increments until full.  First time I've had the tanks full since I 
> started this engine upgrade.
>
> After filling I took a short flight to shake down the 5 or 6 changes 
> I'd made(NACA augmenters, exhaust outlet diverters, crankshaft seal 
> plug(what a nightmare!), yet another oil leak fixed)..  I smelled fuel 
> during the flight.
>
> Landed and pulled the rear seat out and couldn't see any leaks in any 
> of the plumbing, its all new, hard aluminum...   Made another longer 
> flight and the smell got worse.  Had to turn on the external air vents 
> and cut short a planned 1 1/2 hour flight to 1 hour.  Once back on the 
> ground I was pawing around in the back and found a wet spot near the 
> fuel fitting on the right side of the fuselage.  Bummer!
>
> I need to go down and drain that tank today, all 25 Gallons. I may 
> need to drain the other one to make the repairs.
>
> So I want to get the order of repair correct.
>
> 1.) Drain tanks, expose area(remove interior covering)
>
> 2.) pressurize tank with shop vac and use soap to locate hole(s).  How 
> much pressure?  I think the fuselage in that area is a sandwich, 
> glass-foam-glass.  So do I need to grind through the inner glass and 
> foam to find the point of leakage through the fuselage outer glass, 
> which is the actual fuel tank?
>
> 3.) Prep area for sealing.
>
> 4.) Apply vacuum using shop vac to tank,   apply warm epoxy, allowing 
> vacuum to suck it into hole.  Not sure how long you apply the suction? 
> 1/2 an hour, until epoxy gells?
>
> 5.) verify fix using shop vac and soap?
>
> 6.) fill area with micro and apply new inner layer of glass
>
>
> Is this correct?
>
> Scott
>