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Fuel Tank Sealer

Repair Gas Tanks

item(s): 49216


POR-15 Fuel Tank Sealer

POR-15 Fuel Tank Sealer was formulated and developed in our own laboratories due to the demand for a high-tech sealer impervious to all fuels, including the new Stage II fuels which have a high alcohol content. POR-15 Fuel Tank Sealer has superior strength and fuel resistance. POR-15 Fuel Tank Sealer stops rust, corrosion, and fuel leaks.

Formerly U.S. Standard Fuel Tank Sealer

- POR-15 Fuel Tank Sealer Technical Data Sheet

Step-by-Step Restoration

Before Fuel Tank Repair
Before: This fuel tank had small pinhole leaks on the end near the seam. If the tank had a competitors old failed sealer, it should be removed with POR-15 Strip Gel before starting the repair process.
Step 1 fuel tank repair
Step 1:Mix 1 quart Cleaner Degreaser with 1 quart of hot water. This solution will be used to remove any gum, varnish or sludge from the inside of the tank.
Step 2 fuel tank repair
Step 2: Pour the entire bottle of Metal Prep to dissolve rust, coat the tank with zinc phosphate, and etch the metal for better adhesion of the sealer.
Step 3 fuel tank repair
Step 3: After the tank is clean, drain the tank and rinse thoroughly with water. Let the tank dry. When totally dry, pour in the entire can of Fuel Tank Sealer.
Step 4 fuel tank repair
Step 4: After all surfaces have been coated, drain the tank for about an hour to remove excess sealer from the tank.
Completed fuel tank repair
Step 5: Once repaired, use fuel preservation & stabilizer to keep your entire fuel system in proper working order and to avoid "stale gas" problems in your future!

Customer Reviews

Based on 7 reviews
Por 15 Fuel Tank Sealer

As a former mechanic I am always looking for a quicker one step process. My fuel tanki is a 24 gallon from a 1973 Reinell 19 foot boat. I had done all of the cleaning and prep work to the tank prior to receaving this product. I used a funnel and poored it in, Rolled the tank several times over a 2 hour period. I then dumped the excess. I let the tank set on a level platform for 3 days to properly dry. I also left the holes open to vent. I tested the tank with fluid and the sealer works perfect

POR 15 Fuel Tank Sealer

Had a small link in a gas tank on a tractor around the coupler for the filter. I cleaned the tank using the POR cleaner and then applied the sealer. After rotating the tank and making sure the product covered the tank I drained off the excess and placed the tank in the sun. It sat there all day and overnight. Assembled the tank and filled with gas. No leaks. Great product for my application. Not sure how it would work on tanks with larger holes.

Fuel Tank Sealer

Order was processed quickly and the sealer appears to work just as advertised. Thanks for a liquidity, hard to find product

Give it a try!

I restore antique small engines as a hobby. Recently I had an old Briggs & Stratton Model N with a cylindrical gas tank that is rounded on both ends. One end had at least a half-dozen pinholes in various places where the tank was so badly corroded. I also had a General Engines fuel tank that wasn't perforated like the B&S but had an inch-long split on one end. Both tanks were unrepairable using conventional mechanical methods. Rather than toss them away I figured it was worth a shot giving this sealer a try. I had nothing to lose. I was astonished at the results. If you take the appropriate preliminary steps for cleaning and prep, the finish is great. They look like brand new tanks inside. Just don't be in a rush. I let the sealer cure for a week.

Not pleased yet!

I bought this sealant to seal an old fuel tank for a 1982 Yamaha RX 50 that had rusted out and had several pin holes in the bottom. I soldered the holes, added the sealer to it and waited four days as per instructions. My son picked it up two days ago and I haven't heard back yet. I was satisfied with the test I ran with kerosene but it remains to be seen what gasoline will do the sealant.


  • POR-15 Cleaner Degreaser
  • POR-15 Metal Prep
  • Latex Gloves
  • Eye Protection
  • Bucket and access to water and a garden hose
  • Soft rags for wiping any chemical spills on the exterior of the tank
  • Duct tape for sealing up openings in the tank (petcock hole, etc.)
  • Work bench and/or soft padding to lay the tank on
  • Sandpaper


It is important to understand each product in your repair and how it works. Proper chemical interaction is essential for achieving the best possible bond of the sealer to the inside of the tank. Fuel Tank Sealer does not adhere well to plastic. If your fuel tank contains plastic components inside, they should be removed before applying Fuel Tank Sealer. Call POR-15 support for assistance if you are unsure on how to proceed.



PREPARATION: Empty tank of all fuel and rinse out with clean water; remove fuel petcock, float, filters, fittings, etc. Seal up those openings in the tank with duct tape or cork to keep the solutions in the tank when you clean, prep and seal the tank.

Outside painted surface of your tank should be protected from preparation and sealing products with soft rags or other suitable protection.

Mix your 1st quart of POR-15 CLEANER DEGREASER with 1 quart of WARM water. Extremely hot water could melt the adhesive on the duct tape. Pour the mixture into the tank, shake vigorously, and “roll” the tank around to ensure the cleaner gets to all inside surfaces for a minimum of 30 minutes. You may add a chain or nuts and bolts inside the tank to help knock rust and varnish off when shaking the tank. Now empty the solution from the tank and rinse it out with water. Repeat with 2nd quart of Cleaner Degreaser if necessary.

NOTE: Tank should be empty of rinsing water but does not have to be bone dry before using POR-15 METAL PREP.

Pour the entire bottle of POR-15 METAL PREP into the tank. Roll the tank around to ensure it coats all surfaces. Place the tank in different positions every half hour until the entire inside of the tank has been treated with POR-15 METAL PREP. Rinse the tank thoroughly with WARM water several times and drain it thoroughly (low spots in tanks collect water so be sure to roll tank around to get as much water out as possible). In order to get the tank completely dry, you must blow warm air into it because no tank will dry out on the inside by itself. The only way to do this job is to use forced air. This can be accomplished by using a hair dryer or hot air gun. Do not use unfiltered compressor air.


NOTE: Once the metal is treated, it can flash rust. Though the coating is designed to bond with any new flash rust, ideally you’ll want to perform the forced air drying promptly after draining the tank, and coat the tank with sealant soon after drying it.

PATCHING – If you have any big exterior or interior leaks we recommend performing this step before the sealant step. There are several methods to fix holes, but you must fix them BEFORE you put the POR-15 Fuel Tank Sealer into the tank. First, remove all paint aroundProduct InformationMotorcycle Fuel Tank Repair KitEverything you need to prepare and seal your motorcycle fuel tank area to be patched and clean using POR-15 Cleaner Degreaser. Soak area with POR-15 Metal Prep and keep wet for a minimum of 30 minutes; then rinse with water and dry. Next, paint area with a liberal amount of POR-15 Fuel Tank Sealer and place a small piece of repair cloth over the wet painted area. Now, apply POR-15 Fuel Tank Sealer over repair cloth from the center outward so that the painted cloth is stretched evenly over repaired area. Let patched area dry until the area is dry to the touch with a slight finger drag before pouring the remain- ing POR-15 Fuel Tank Sealer into the tank. If you are just patching and not sealing the entire tank let the patched area dry for 96 hours before adding fuel to the tank.

If you aren’t aware of any holes, check to make sure you don’t have new ones now that the chemicals have removed the rust layer. The tank cleaning process may reveal new leaks in the tank after removing rust and rust deposits from weakened and thin tank walls.These areas are likely to be in the low points and seams, especially if there are low tank areas below the level of the petcock. These areas may have collected water from tank condensation and water in your fuel and over time may have corroded the tank metal.

Carefully check these areas for leaks when you have fluid in there (it will only be a very small trickle if there is a pinhole leak.)

SEALING: Open the POR-15 Fuel Tank Sealer and stir until a uniform color is achieved.

CAUTION! Pour entire contents of can into the tank. Roll the tank SLOWLY to ensure it coats the insides uniformly. In tanks with seams, and with low areas below the opening through which you are draining the sealant (typically the petcock hole) the sealant will puddle. Take great care to ensure you’ve drained out the excess and not allowing the sealer to puddle.

IMPORTANT! This is a very strong and durable coating. Take care to immediately clean surfaces on which you may have spilled the sealer. Any sealer remaining on painted surfaces will become permanent. Any excess sealer must be cleaned from screw threads for the petcock before it dries. A clean soft rag can be twisted into the screw holes to clean the material out.

FINAL NOTES: Let POR-15 Fuel Tank Sealer cure for at least 96 hours (4 days) before pouring in fuel.

WARNING: Cancer - www.P65Warnings.ca.gov.