Reel Repair by Alan Tani

While working on the Rude I was gonna put fresh gas in the spare tank.

Sitting in the boat for years it had rusty water in it. So I bought  a new plastic tank to eliminate fuel issues.

I would like to keep the old metal tanks though?
Any restore tips?

Having done this for old motocycles, boat cans and metal gas containers, here is my method for clearing out rust and prepping a metal fuel tank for use:

Step 1: Initial Rinse
Flush the tank with water or acetone to wash out the loose rust. Acetone is ideal here because it evaporates and dries much faster.

Tip: Save your used acetone by pouring it through a paint filter into a separate container—you can reuse it for future cleaning steps.

Step 2: Mechanical Abrasive Scrub
Drop a handful of small metal nuts, bolts, or coarse glass (such as aquarium or fire pit glass) into the tank. Shake the tank vigorously in all directions to knock loose any stubborn, stuck-on rust. 

Tip: Before you shake the bolts and nuts around, remove the hose adapter from the tank and cover the hole with tape.

Step 3: Flush & Repeat
Give the tank another acetone bath to rinse out the dislodged debris. Repeat Steps 1 through 3 until the inside of the tank is completely free of surface rust.

Step 4: Seal or Protect
Once you're satisfied with the interior:

Option A (Permanent Sealer): Apply a dedicated fuel tank sealer kit (such as the one made by Eastwood) according to the package instructions.

Option B (Oil Coat Option): If you plan to put the tank right back into service, pour a small amount of 2-cycle oil into the tank and slosh it around to coat the raw metal and prevent flash rust.

Note: If you use the 2-cycle oil method, make sure you install a clean inline fuel filter on the supply line before connecting it to your outboard motor.

I only used AI here to assist my writing and make my instructions more consise and clear. The method came from my father-in-law an old John Deere mechanic.

In my C130 A/C days we pressurized
The wing tanks & checked for leaks.

When a leak was found the rivet or hilok was R/R & slathered with some
green sealer before the install.

I figured there was a way to coat the inside of the tank with sealer.

I agree with JT on his methods, but as a caveat you can also use pea gravel or aquarium gravel as a rust scouring aggregate. I used it on an old 56 Evinrude pressurized type tank and it worked great and has lasted seven years so far. 

Tom, are you running a '56 Evenrude?  If so, that's a whole lot more impressive than cleaning rust from the tank.

When i was a motorcycle mechanic I used a similar method to clean fuel tanks, but using lead shot as an abrasive to eliminate the chance of generating a spark.  -  Jimmer

Quote from: oc1 on August 11, 2026, 06:34:18 AMTom, are you running a '56 Evenrude?  If so, that's a whole lot more impressive than cleaning rust from the tank.

I'm personally not running it now, I gave it to my daughter and son-in-law 4 or 5 years ago along with a '60 14' Alumacraft FD & trailer. They keep it in the boat house @ our cabin and use the combo quite a bit.

They were originally my dad's. He got them both slightly used/near new. I used them for years and my son used the boat until he bought my dad's '82 16' Lund.

The motor is 7.5 hp Fleetwin. It was before 50:1 & takes a 16:1 mix. Those things smoke a lot when trolling (keeps the mosquitoes away, though  ). It didn't get used for quite a few years, and even though all the fuel had been dumped out of the tank, the inside of the tank got some rust so I had to clean it up. The coils cracked, too, from old age, so I had to get new coils for it. That old motor runs great!

I have 4 Johnson tanks from the 70s just like yours they are Great Tanks and take  abuse better than the plastic ones. I had internal and external issues with rust and resolved it quickly by having them sand blasted; followed up with several rinses with a good cleaning solution. Use an air compressor to blow out any doubts about left over moisture or abrasives.   Then, a fresh coat of automotive engine paint. Steel tanks are expensive to replace and worth the effort to freshen up. I painted mine white , as red heats up quickly in direct sunlight and doesn't seam to expand and contract as much when left half full at the dock

I used POR-15 several years ago to clean and coat a motorcycle gas tank. I was happy with the results.