Guidance for draining tanks

[M20F-1968]

This is a question about how to safely de-fuel the airplane.

My JPI 930 fuel tank gauges need to be recalibrated.  I have Monroy long range tanks and and am using the current production style fuel senders (2 in each tank).  I do have a fuel totalizer connected to the turbine wheel type sender.

The JPI was never properly calibrated.  With the long range tanks, the actual fuel volume is not equally divided for every 1/4 tank increase on the JPI gauges.  I believe the maximum data points allowed by the JPI 930 are five data point, empty, 1/4, 1/2, 3/4 and full.  I wish I could calibrate the JPI with more data points, such as every 5 gallons, but apparently that is not possible.

My plan is to burn off as much fuel as I can in one tank and then empty the remaining fuel into a 5 gallon bucket and put it in the opposite tank.  Once one side is correctly calibrated, then I redo the some procedure on the other side. 

My question for the forum is what are the precautions I should take in draining the one tank and moving fuel to the opposite side?

Thing I recognize are:

1. Ground the airplane.  May use an auto jumper cable with alligator clips on each end, exhaust pipe to steel structure in hanger or electrical conduit.

2. Use a steel bucket to drain fuel into and ground the bucket as well

3. Have no carpets or blankets in the area which could generate static electricity

4. Avoid climbing in/out of plane

5. I plan on using the fuel sump drain to drain the remaining fuel (I know it will take some time) with a wire or string I can access through the pilot's window to pull up on the sump drain.

6. I have a filtered funnel for the other tank which is screened and separates out water as well (as I recall).

7. Perhaps leave the hangar door open to minimize fumes (but it is winter here).

8. Shut off the propane furnace (should I also shut off the pilot flame)?

9. May I leave lights on?

I am obviously worried about the flammability issues while handling fuel.  Is it safe to do this in a T hangar?

Your thoughts are appreciated.

Should I simply but a pump and sealed can rated for fuel?

Or perhaps delegate this to a local mechanic, but I may be thinking more about the problems than a paid mechanic will.

John Breda

ANY OTHER THOUGHTS ON HOW TO 

 

[M20F-1968]

SORRY about the double post.  This one got sent prematurely.  Please respond to the other one with the same title.

John Breda

[Yetti]

Don't do it in the hangar where fumes can linger.   And do you really want to burn up your neighbors planes.   Seems easier to fly it, fill it up and subtract how many gallons were in the tank, then update the fuel gauges.

 

[Hank]

Fly one tank empty, at least until the engine stumbles. You don't want your JPI to include unusable fuel. Then there's no need to drain anything on the ground. 

[MinneMooney]

Ventilation is important. Gasoline vapors are heavier than air and will flow to low spots and accumulate. Eliminate any potential sources of ignition!

[Hector]

I think you got it covered. Make sure hangar door is fully opened for ventilation.


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