What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Flushing Fuel tanks

Swingwing

Swingwing

Active Member
My wings with the tanks tested and installed were stored in a garage for about ten years. The tank drain, fuel, and vent connection points were uncapped. Through the fill caps, they look clean, and I plan to bore scope them to get a better look.

Should I flush them with fuel to remove any dust, dirt, or construction debris before the final installation, or can it be done on the plane using the pump and cleaning the filter?

Thanks,
Nick
 
What I do:
- The final tank leak test is done with ~5 gallons of 100LL. The tanks are left to sit for a few weeks in three positions; vertical (resting on the tank skins, leading edge up), top skin up and top skin down. The objective is to identify any weeping rivets that did not show up doing standard leak test.
- I put white paper towels under the tanks to act as witness paper for leaks.
- Once done, some easy sloshing of the fuel in the tank and then drain via the tank sump using a cheap inline filter. Repeat using the now filter fuel until happy with the tank flush.
- Once the tanks are on the wing and the wings mounted, do the standard fuel sender calibration. Pump the fuel using the boost pump and filter to five gallon gas cans. If you want you can use the planes filter or temporarily replace it with the cheap inline filter.
- While pumping measure fuel flow (as in how long it takes to fill up the five gallon gas can).
- Remove the inline filter and inspect. If clean you are good. If not repeat as needed until it is.

Carl
 
Carl Froehlich said:
What I do:
- The final tank leak test is done with ~5 gallons of 100LL. The tanks are left to sit for a few weeks in three positions; vertical (resting on the tank skins, leading edge up), top skin up and top skin down. The objective is to identify any weeping rivets that did not show up doing standard leak test.
- I put white paper towels under the tanks to act as witness paper for leaks.
- Once done, some easy sloshing of the fuel in the tank and then drain via the tank sump using a cheap inline filter. Repeat using the now filter fuel until happy with the tank flush.
- Once the tanks are on the wing and the wings mounted, do the standard fuel sender calibration. Pump the fuel using the boost pump and filter to five gallon gas cans. If you want you can use the planes filter or temporarily replace it with the cheap inline filter.
- While pumping measure fuel flow (as in how long it takes to fill up the five gallon gas can).
- Remove the inline filter and inspect. If clean you are good. If not repeat as needed until it is.

Carl
Click to expand...

thank you, Carl. I did not think of using cheap inline filters to flush and inspect, Great idea!
 
Plan

Once my wings are installed, I plan to calibrate the fuel gauges using water. I could add a drop of soap to break the surface tension and also use the water to flush the tanks. I plan to keep the fuel shutoff valve close whenever water is present. After this, the fuel flow tests, with avgas, should further flush the system of water and other junk. Just my plan.
 
My tanks were flushed with fuel 3 times. 20 years later I very rarely find an aluminum chip in my gascolator - like maybe every 3 years.
 
You must log in or register to reply here.
Back
Top