How to Seal & Restore a Gas Tank

Over time, your vehicle’s gas tank can start to corrode and even leak. That is why is is important to know how to restore your gas tank to rid it of any rust and seal any minor leaks. Below, we take a look at how to properly seal and restore your gas tank.

Gas Tank Sealing and Restoration: Preparation

The first thing you need to do is gather your materials. You will need: the Eastwood Gas Tank Sealer Kit, muriatic acid, 64 oz. of acetone, two gallons of hot water, a bucket and some safety gloves and goggles. If you have a small gas tank that holds one to five gallons, you will only need one pint of the Eastwood Gas Tank Sealer (included in the Gas Tank Sealer Kit). If you have a larger tank, use two pints per 20 gallon-capacity. If your gas tank contains baffles, increase the surface area, and be sure not to coat the tank if the tank, sealer or room temperature is below 60 degrees. Make sure the tank is completely dry and free of water before applying any surface prep solution or sealer.

Make sure that you have enough time to complete the entire restoration job before starting to seal and restore your gas tank. The first thing to do is drain and remove the tank from your vehicle. Use warm, soapy water to wash out and rinse the tank entirely. Remove any valves, sending units, petcocks and internal filters from the tank, and make sure that the fill spout is the only opening in the tank. Now, it is time to start cleaning the inside of the tank.

Gas Tank Sealing and Restoration: Execution

First, mix the contents of your metal wash solution (from the sealer kit) with your two gallons of hot water in a bucket. Pour the mixture into the tank and slosh the contents around before letting it sit for five minutes at a time on each surface. Slosh the tank around again, and pour out the solution before thoroughly rinsing the inside with a hose. If any varnish inside the tank still remains, repeat the sloshing and rinsing process until all traces of varnish are gone. In an outside environment, add three ounces of muriatic acid to 60 ounces of water, making about half a gallon of 20-to-1 water-to-acid solution. It is important to wear your safety gloves and goggles during this process. Now add your diluted muriatic acid solution to the tank and slosh it around for about five to ten minutes. Make sure one opening is loosely capped to allow pressure to escape the tank. Repeat this step until all rust inside the tank is gone. Then, pour out the contents into a plastic container and neutralize the acid solution with baking soda until the fizzing ceases.

After thoroughly rinsing the tank multiple times of all remaining solution, pour the entire bottle of Fast Etch (from the sealer kit) into the tank and slowly rotate it, allowing all surfaces to come in contact with the solution until the inside is consistently gray. Next, pour out the contents, and fill the tank will one quart of acetone. Slosh the acetone around inside the tank before pouring it out. Now, repeat this step with fresh acetone. After you empty the tank again, shake your Gas Tank Sealer, pour it into the tank and coat each inner surface by rotating the tank slowly. Open the fill spout, and let the tank sit for eight to ten minutes. Close the opening again, and slowly rotate the tank once again with the solution in it. Let the tank sit again for eight to ten minutes on a different side. Repeat this process multiple times until the inside has an opaque white coating. This solution should be allowed to dry inside the tank, each side equally coated. In order to properly prevent the sealer from collecting and drying unevenly on any one side, insert an air compressor line into one opening of the tank with all other openings closed, at between one and five psi. The tank should be completed dry within 48 hours at 60 degrees or warmer, and the coating should ultimately be rubbery with no odor emitting from inside the tank.

If you want to further protect your gas tank from rust, use Eastwood’s Tank Tone Metallic Coating. This solution contains zinc to prevent against any initial spread of corrosion inside your tank. After the entire process is complete, always be sure to store your Eastwood Gas Tank Sealer Kit at 70 degrees or cooler for an optimum three-year storage life. Also, for any clean up, use methyl ethyl ketone or acetone solutions, but be sure to dispose of them safely and legally. Be safe when working with these chemicals, and always make sure you use the proper equipment to successfully seal and restore your gas tank.

To learn more about sealing gas tanks and for various DIY car tutorials, be sure to visit

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