Cleaning main tank?

[1938BF50]

Anyone have any suggestions for cleaning my main tank in place? Very light rust flecks and lots of white powder light residue. I am hoping someone has had good luck with a cleaner? I have a temp fitting and valve on the outlet so that I can rinse and flush.

[Guest]

I dried mine out then vacuumed the bottom with a piece of tubing taped to the end of my shop vac hose. That's what I recall doing.

[1938BF50]

Thats a good idea. I would feel better If I could somewhow wirebrush the entire inside and then flush with a cleaner that would remove any remaining residue. Is this an F-19 or F-21 main tank? At one time the plane was set up with the Harer 85hp conversion.

[1938BF50]

Another view

[Guest]

One of the best methods that I have found to dry out a tank is to leave a cap off then attach a male air hose fitting to a port that is the farthest away from the uncapped point.

Then attach an air host and set the regulator so you just hear a small hiss.

Keep the flow going but at a very low rate.

I have taken a tank that had fuel in it and let that air bleed thru there over night then weld it the next day.

In some cases it took less time. Just smell the air coming out of the opening, you can tell from that.

Dave R

[PA1195]

Is that a Taylorcraft tank? Looks like what I've seen on Aeronca Chiefs with the fuel gauge near the instrument panel. Just curious but look up that plane for pics.

One cleaner that I've used on other tanks is CLR https://clrbrands.com/Products/CLR-H...e-Rust-Remover Mix with water then flush and dry maybe a couple of times.

Gary

Edit = Obviously this cleaner contains an acid per their ingredients list. Test a small spot externally first. Another option would be to have a radiator shop steam flush the tank like they do for cooling systems and radiators. If just light corrosion is suspected plain dilute vinegar and detergent can sometimes work.

Edit = Alternatively someone from a time long past welded an Aeronca fuel gauge on a Taylorcraft tank. A gauge on the tank is required as part of Harer's STC SA1-210 C-85 conversion along with a vent line to and between aux wing tanks, plus a sealed filler cap. The typical gauge is a Rochester round unit near the vent outlet like the F-19s used. But back then common sense and ingenuity prevailed.

[Scott]

Id be inclined to use varsol and a scotchbrite pad attached to an aluminium rod (1/4" maybe) that you can bend to reach all the contaminated areas.
Look through one opening and manipulate the rod through the other. Flush with more varsol and a paint brush to chase all the bits out the outlet.

Assuming the tank is aluminium, if the varsol doesn't do the trick, try alumiprep 33.

[PA1195]

Interesting windshield standoffs....Adel clamps, bolts and nuts, covered with rubber ends.

Gary

[N96337]

A gauge on the tank is required as part of Harer's STC SA1-210 C-85 conversion along with a vent line to and between aux wing tanks, plus a sealed filler cap. The typical gauge is a Rochester round unit near the vent outlet like the F-19s used. But back then common sense and ingenuity prevailed.

I've never seen that part of that STC and I've done a few. Did I just sleep through it?
John

[PA1195]

I believe it was either added to the STC or was a subsequent compliance option when the CAR 4 BC12D-4-85 and CAR 3 Model 19 equivalents were added in 1971 on the STC. Probably applies to later -4 motor setups with the long mount and others. Under TCDS 1A2 required for the Model 19 and F-19: Note 2. (h) “Main tank usable fuel 9 gal.” (Must be displayed above the fuel selector valve) How else would that minimum quantity be measured?

It was done to mine during restoration so maybe they did it to comply with the placard's requirement. The setup matches F-19's I've seen. See Page 8 for 85HP, F-19, F22:
http://www.univair.com/content/partc...nteractive.pdf

And here Page 5: https://www.taylorcraft.org/docs/Tay...anual_1985.pdf

Unlike earlier CAR 4 planes, for the CAR 3 Model 19's 1500 GW a Flight Manual was included in my STC.

Gary

[lawheelock]

My BC12-D -65 was partially restored many years ago including a new fuel tank from the factory while they were still in business. It has a replacement tank from the factory with the F19 configuration. I have to believe that that was the only tank available at that time and that it was OK to install it. Somewhere, I may have some paperwork about it. One of the apparent requirements was to have a vent tube run up inside the cockpit along one of the brace tubes, and go through the ceiling with a bent vent tube facing forward on top of the cabin. Otherwise, the installation is the same as what BC12-Ds had originally. This does away with the cork and wire fuel gauge in the filler cap. Since I am in an extended period of repairing this plane I only flew it a time or two when I ferried it from Northern Indiana to Terre Haute for the former owner and rode around with him a couple of times getting him fal\miliarized with the plane before he wrecked it landing in a muddy field across corn rows and damaging the landing gear fitting on the right side and the left wing rear spar at the root.
Larry Wheelock..

[PA1195]

Larry I've I think I've seen the single vent tube with forward vent (adds air pressure for full fuel flow at high AOA and power) plus a lower sealed cap to maintain that pressure differential. If wing tanks are added under STC SA1-210 then their fuel caps require that forward vent design. The STC has a drawing for that mod but I have Atlee Dodge Cub caps that are similar and comply with the requirement.

Gary

[Hank Jarrett]

I dried mine out then vacuumed the bottom with a piece of tubing taped to the end of my shop vac hose. That's what I recall doing.

Be REALLY careful using a shop vac to clean out a tank. The air you pull from the tank will have a LOT of fuel fumes and most shop vacs take the air after the filters to blow through the motor to cool it. You can blow fuel fume laden air across the brushes and that can tend to get noisy! Haven't ever seen it on a T tank but it makes car fuel tanks take on some really funny shapes too!
Gary (PA1129) has the best idea (if you can take the tank out). Take it to a radiator shop and let them steam clean it. If it needs any welding they also know to flood the inside with CO2 while welding (at least the smart ones!) It takes VERY LITTLE fuel fume to cause an explosion and simply repeatedly flooding the tank and draining it with water will not do it.

Hank

[1938BF50]

Thanx for the warning Hank. The tank had been dry for nearly a year. The fuel gauge and the outlet were open for air exchange. I ended up wire brushing dry with bent gun cleaning rods for the big chunks. After installing a temp valve in the outlet, I put a half gallon of boiling water in the tank that I let sit for an hour. I scrubbed again with the nylon brushes and the tank is now nearly spotless. Most of the discoloration was an algae farm from car gas turning to who knows what....

[lawheelock]

There is a safe way to vacuum a fuel tank. Aircraft Tool Supply sells a couple of small vacuum cleaners that use the venturi principle to create vacuum and air from an air compressor. While the CFM requirements are fairly high, it still can be an effective way to vacuum loose debris in a fuel tank. Two tools are available from ATS: Catalog Number ATSMV01 listed as around $26 in my printed catalog and catalog number WG01 for around $36.00.
Removing the main tank in a Taylorcraft is no easy task. I removed the tank from the wrecked F19 that I bought for parts and getting the rods that go through the interior of the tank required that I remove the instrument panel. Of course, the firewall and tank had been damaged, so it might be a little easier on a non damaged plane.

My BC12-D has factory equipped 6 gallon wing tanks that the caps originally had small forward facing vents. It never had the STC for the larger engine.

Larry Wheelock