Making the inside of your gas tank look brand new for $10

[Lucas_riley]

This worked great for me, hope it helps someone else. To remove rust from inside your gas tank, go to the grocery store and get enough apple cider vinegar ($5 a gallon) to completely fill your gas tank, as well as a gallon of distilled water. Drain the gas from your gas tank. Next, plug/close off the gas lines. Fill the tank completely with the apple cider vinegar, then put your gas cap back on. Let it sit for 36-48 hours for best results.
Remove gas cap, dump out around half of the vinegar, then put gas cap back on and shake it to stir up any loose sediment. Then completely drain the vinegar from tank. The vinegar is very acidic, so you will need to take your distilled water with a few tablespoons of baking soda, and rinse out the tank to neutralize the metals. If you do not do this, it will flash rust within a day, and you are back to square one.
I have done this to 2 different tanks, and had awesome results. It completely removed 100% of the rust and sediment. This however does not re-seal the tank. I also took an air hose and blew out any sediment that didn't come out with the rinse. Incase you don't rinse the tank well enough to keep it from flash rusting, simply re-fill the tank with gas.
Like I said, I have done this to 2 separate tanks with great results. I have heard other types of vinegar works, however I have not tried it.
This has worked great for me, hope this helps others.

[YTZ drew]

I do the same thing, only I add one to two steps. To help me remove the moisture after the rinse, I dump a whole bottle of cheap store-brand rubbing alcohol in the tank and slosh it around. Then drain, and air-dry again. If I'm not going to use the tank for a while, I dump a small bottle of cheap pre-mix 2 stroke oil in and rotate the tank all around to coat the inside and protect it until I'm ready to use it.

[shdtreemechanic]

I did something similar to an old lawnmower tank I used about 1/4 of a bottle heet sloshed it around in the tank with about a tea cup of gas and it was good to go

[ebaccm26]

Lots of different things will have the same effect acidity wise but usually no matter what liquid I use I will throw some nuts, bolts, screws, etc. in the tank first and shake it around, helps get some of the bigger chunks broken loose which can expedite the process for the slower (less acidic) liquids.