D14 gas tank rust

Before you do all that, try what I've always done and with good success. If the tank is dry on the inside, stick a small hand held sand blaster in the fill hole and rotate it at an angle to hit as much of the tanks bottom as possible. I'm talking swimming pool type sand or glass beads. Suck everything out with a shop vac. If the tank is damp, power wash it out several times, then let it dry and sandblast if needed and vac empty. I've always gotten the tanks clean enough they aren't a problem any more.

YUP.

big inline filter... or a drop leg sediment trap would help..

I bead blast/sand blast thru the top fill hole AND the sediment bowl hole.

Harbor Freight sells a little hand held sandblaster with a small nozzle. It works good for small jobs like this.

Couple of thoughts; I have used for-15, so far, so good. Tank was very shiny so following the directions made it easy. It wasn't a rust issue I was trying to seal. Tank had some sort of impact damage and brazing rod just would not fix it.

Just got back from the machine shop. Since I decided to go this route I figured I would just go ahead and sandblast the entire tank while I had it in the cabinet. The only hole the nozzle would go through was the fuel gauge hole which was fine, works better at an angle anyway. I was able to shoot down through the fuel fill hole but only as far as the tip would go in. The blasting cabinet has a foot pedal to vary the pressure you use so I’m able to hit areas with low blast or harder areas with higher pressure. This allows blasting of fragile items or in the case of the outside of the tank I could use a higher pressure to get the paint and rust off quicker. Now I have a spotless tank inside. This thing was bad and was actually afraid of blowing a hole in the tank if the metal was weak. I tapped on the bottom before I started and it seamed not to have any weak spots in it. Wish I would have taken before and after pictures because you wouldn’t believe the difference. Thanks Doc for the suggestion, sure beats chemicals and if I hadn’t done the entire tank I could have gave it a good bath inside, dried it with my shop vac and had it back on the tractor going for a ride this afternoon.
Thanks for tips everyone. No doubt there are multiple ways of getting them clean but this was by far the easiest. In 5 minutes the inside was cleaned. There was so much red rust dust blowing out the holes I couldn’t see the tank through the glass when I first got started! Now she looks new again and surprisingly no pitting that I can see. Also blasted the left rear fender so I can do some body repairs to it. Guess I will be riding around this summer with a green etching primer tank, fender, and battery box until I paint it this fall. The ugly duckling I guess you could say. Oh well, as long as she runs great this year during hay season then she will deserve a paint job.

Edited by AC720Man - 14 hours 48 minutes ago at 12:50pm