My 10 yo helped me clean the inside of the tank. I had a lightly rusted area about 2"x 2" that came off easily. Should I coat this tank or just leave it bare?

Now I can see why you needed a 10 year old. You could use the POR 15 material.

DAvid

I've waited 10 years to have the tank cleaned. But the question is should I? If I don't will it get rusty? Are today's fuels going to rust it out?

Best way to remove rust from a gas tank/ / / Go to home depot. . In the cement section they have a gallon jug of cement etching acid. it's around $12= green color if I remember correctly. . . . it's really phosphoric acid. . . mix it 2:1 with water, , slosh it around in the tank for 20 - 30 minutes. . it will convert the rust and clean everything else bright steel. . rinse with baking soda and water to neutralize. .
if the rust is heavy. throw in a hand full of small screws and washers. . shake the hell out of it. . . I made a sling from a tree to support the tank, and all you have to do is rock it around. .

the only prerequisite is that the tank needs to be substantially good meaning not almost eaten through from the rust. . and then you need to figure out how to dispose of the waste. .

I don't have a big problem with leaving it.

Add lots of baking soda to the waste and your good to go. Neutral PH will not harm (most) anything.

Here is what I do. The tank in the photo is for a TR6, but I did the same for a badly rusted 914 tank. I used evaporust for a week at about 100 degrees F, and then a couple of days with a mix of nuts, bolts, chain and WD-40 cycling around in this contraption. Shafts tack welded to flange on tank. LOUD. Click to view attachment

And when you're not cleaning a tank with it, you can roast a pig or something. Yankee ingenuity at it's best.

Is there a good rattle can paint for the outside of the tank that won't get screwed up if I accidently get gas on it? I had a recommendation from a paint shop for the VHT product for its chemical resistance.

I see some design flaws for its use as a pig roaster!
SW

WolfsburgWest Gray/Black L43. Hard as nails & a near perfect match to ealy tanks.

I took mine down to bare netal & used liberal coats of primer, block sanded with 1000 grit - 2 coats. The L43 took to it like glue. Three coats, 1000 grit each, followed by wet sanding with 2000 grit, and high quality wax (I used Zynol). Came out perfectly.