Gas Tank Sealer Kit

Repair & Restoration Instructions


Eastwood's exclusive gas tank sealer kits have nearly everything you need to clean a rusty, old, varnished gas tank of all the fuel residue and gunk, and seal it with a virtually impervious internal coating. If you are careful, you can even use it to coat the inside of a motorcycle fuel tank without effecting the paint job on the outside. One kit seal tanks up to 5 gallons, and a few additional pints of sealer are all you need for larger tanks. Each additional bottle of sealer adds coverage for 10 to 12 gallons for tank internal surface area.




Additional Supplies Needed


  • 1. 64 oz. Muriatic Acid
  • 2. 32 oz. Acetone
  • 3. 2 gallons of hot water
  • 4. Bucket
  • 5. Safety gloves and eye protection

Sealing Instructions


Read all instructions before using this product


QUANTITY REQUIRED: For small tanks (1 to 5 gallons), use one pint (16 fl. oz.) of Eastwood Gas Tank Sealer. For larger tanks, use roughly 1 additional pint per 10 gallon capacity. If the tank contains baffles, be sure to consider the increase in surface area. Sealer works best if tank, sealer and ambient temperature is 60°F or higher.


SURFACE PREPARATION – CAUTION: Surface prep solutions and sealers will damage paint. Tank must be absolutely dry and free of water before applying sealer. Read and understand all instructions before use.


  1. 1. Read all instructions and plan work so that the entire process is completed in one session. Do not allow tank to dry between sessions – move from one step to another until complete. Drain and remove tank from vehicle. Wash out tank with hot, soapy water and thoroughly rinse with water from running garden hose. Remove valves, sending units, petcocks, and internal filters. Stop all openings except fill spout.

  2. 2. Mix entire contents of Metal Wash (https://www.eastwood.com/metal-wash-7-oz.html) with 2 gallons of hot water in a clean bucket.

  3. 3. Pour contents into tank and "slosh" around. Let it sit for 5 minutes on each surface. "Slosh" around again until all fuel varnish is removed then pour out contents. Thoroughly rinse with water from running garden hose. At this stage tank should be free of all fuel varnish. There may be areas of clean bare metal and rust but all varnish will be removed. If any varnish remains repeat the Metal wash slosh until all traces of varnish are gone.

  4. 4. Take clean tank outside. Purchase Muriatic Acid (available at hardware and building supply stores). NOTE: Follow proper handling instructions on label of Muriatic Acid, wear heavy rubber gloves, and work outdoors. DO NOT ADD UNDILUTED MURIATIC ACID TO THE TANK!

  5. 5. "Slosh" 1/2 gallon diluted Muriatic Acid around on all internal surfaces to completely remove corrosion – until surface has a uniform gray appearance (approx. 5-10 minutes). Make sure at least one opening remains uncapped to allow pressure to escape. If rust remains repeat the diluted Muriatic Slosh until all rust is gone.

  6. 6. Pour out contents into a plastic container and neutralize by slowly adding baking soda until fizzing stops. Dispose of according to local laws. Thoroughly rinse the tank completely filling and draining the tank 2 times with water from a running garden hose. It is normal for some light flash rust to appear on this surface. This will easily be removed in the next step.


    After completion of step 6, tank interior should be rotating tank in all directions. basically clean with perhaps a little flash rust.


  7. 7. Pour entire contents of Fast Etch bottle into the tank and slowly rotate to allow it to contact all surfaces until there is a uniform gray appearance. Pour out contents into original container and dispose of according to local laws or save for further parts rust removal.

  8. 8. While the tank interior is still wet from the Fast Etch, pour in 1 quart of Acetone (available at hardware and building supply stores). Tank should have a uniform gray appearance. Carefully inspect all tank areas to make sure there is no rust remaining.

  9. 9. "Slosh" Acetone around on all internal surfaces then pour out contents into original container. Repeat step 8 again with fresh Acetone. Dispose of used Acetone in accordance with local laws.

  10. 10. Shake sealer container well before use. Keep container tightly closed when not in use. Stop all tank outlets except fill spout.

  11. 11. Pour Eastwood Gas Tank Sealer into tank, temporarily close fill neck, and coat entire inner surface by slowly rotating tank in all directions.

    instructions for  tank
    12. A properly coated tank should have a uniform bright white coating of sealer free of any puddles. Some excess should remain. Let tank stand for 8-10 minutes with fill neck or sending unit open, then close openings and slowly rotate tank allowing excess to re-coat all surfaces. Let tank stand for an additional 8 to 10 minutes with fill neck or sending unit open however, this time on a different side. Repeat this until the tank has the desired opaque white coating. Do not allow coating to drain to one area and dry. Drain off excess. Allow excess to dry and dispose of hardened material according to local laws.


  12. Forced ventilation is important to prevent sealer from reflowing and puddling and for thorough drying.

    13. Remove all stops and insert a compressor air line, with pressure set at 1-5 psi (keep air line 2" or more away from the coated surface to prevent thinning coating). Tank should be completely dry within 48 hours at 60°F or warmer. Cured coating should be slightly rubbery with no odor before filling tank with gas.

Safety and Clean Up


CLEAN UP: Use methyl ethyl keytone or acetone. Use caution as these materials are flammable and can damage paint.


STORAGE & HANDLING: Store container at 70° F or cooler for maximum 3 year storage life. High temperatures and exposure to sunlight reduce normal storage life. Product should be discarded if sealer becomes discolored. Lower temperatures temporarily increase viscosity.


CONTAINS METHYL ETHYL KETONE – USE WITH ADEQUATE VENTILATION. Avoid contact with eyes; keep from heat, sparks, or flame. Do not smoke. Extinguish all flames and pilot lights. Turn off stoves, heaters, electric motors, and all other sources of ignition during use and until all vapors are gone. Avoid prolonged contact with skin or prolonged breathing of vapors.


FIRST AID: In case of eye contact flush thoroughly with water. If irritation persists, get medical attention. If swallowed do not induce vomiting. Get medical attention immediately. If vomiting occurs spontaneously, keep victim’s head below his
hips to prevent his breathing the vomitus into his lungs.