1. Home
  2. KBS Direction Pages
  3. Tank Sealer Directions

ALWAYS WEAR PROTECTIVE GLOVES AND SAFETY GLASSES. ALWAYS WORK IN A WELL-VENTILATED AREA. Please heed all warnings and caution notices.

FOR BEST RESULTS, PLEASE BE PATIENT DURING EACH STEP OF THE PROCEDURE. DO NOT RUSH!

Importance of Tank Preparation

To achieve expert results, please take the time to carefully read and understand the following directions before you begin your tank sealing project. Ideal Tank Sealer application temperatures are 55°- 82°F (13°- 28°C). Gold Standard Tank Sealer is a moisture-cured urethane therefore use only in moderate to dry atmospheric conditions. Avoid sealing tank in rainy or humid conditions. If the Sealer cures too quickly, surface bubbling will occur as a direct result of gas entrapment beneath the top surface layer of the Sealer. (NOTE: If you are sealing a Fiberglass Tank, please refer to additional instructions provided. Gold Standard Tank Sealer is not recommended for plastic tanks because of the many different types & varying levels of porosities available.)

All tanks, whether old or new, have oils, residues and contaminants that require thorough removal before sealing. The KBS 3-Step System is a specific process formulated to ensure superior adhesion of the coating & its long-term performance. Sealing a tank without proper prep will cause any new coating to fail. If a tank was previously sealed, you MUST remove the old coating first then proceed using the KBS 3-Step System. Choose a paint stripper containing Methylene chloride for the most effective removal. Please refer to additional Tank Stripping instructions provided below.

Step #1 - KBS Klean - Cleaning

1) Drain fuel from tank. Proper fuel tank sealing also requires that the tank be removed from the vehicle. Remove any fittings such as floats, sending units and filters.

2) Seal all openings with duct tape or cork-like stoppers.

3) Using a 1:1 dilution ratio, mix KBS Klean with hot water and pour mixture into tank. Let tank soak but always rotate it at intervals to ensure KBS Klean covers all surfaces. (NOTE: Heavy gum and varnish build-up may require extended soaking times up to 24 hours or more and/or the use of a pressure washer. Placing some nuts & bolts or loose chains inside the tank, along with frequent shaking and rotation, will help knock away loose rust and contaminants.)

4) Empty tank and repeat as often as necessary ... remember the cleaner the tank, the stronger the adhesion of the Tank Sealer.

5) After a thorough cleaning, rinse generously with water until the solution runs clear. Drain tank and let dry.

TIP: Your tank can not be too clean. Please spend the time required on this step.

FOR BEST RESULTS, PLEASE BE PATIENT DURING EACH STEP OF THE PROCEDURE. DO NOT RUSH!

Step #2 - RustBlast - Surface Prep / Rust Removal

1) Pour entire amount of full strength RustBlast into a dry tank. Do not dilute. Continually roll tank around to ensure all interior surfaces are kept wet. Repeat rolling and tipping tank every 5 minutes for a minimum of 30 minutes to 1 hour. RustBlast is an acid metal etch that will neutralize existing rust & also create an anchor pattern ideal for Sealer adhesion.

2) Important: Do not allow RustBlast to dry on surface. This avoids too heavy of a zinc phosphate buildup which can adversely affect the sealing process. After sufficient wet contact, drain & capture RustBlast in a bucket/container. Repeat process as needed. Once thoroughly etched, drain and rinse tank thoroughly several times with water. (NOTE: It is not necessary to remove every last bit of rust before sealing. Gold Standard Tank Sealer is very capable of bonding to & permanently sealing any remaining rust or corrosion.)

3) IMPORTANT: After rinsing, allow tank to dry completely before proceeding. Drying is best accomplished by introducing forced air into the tank by using a shop vac, blow dryer, or fan. A white powdery residue may appear after drying. This is the zinc phosphate coating advantageous for Sealer adhesion. (NOTE: Drying is a critical step. If the tank is not completely dry, the Sealer will not adhere properly.)

4) After a good cleaning & prep and depending on the condition of the tank, any existing pinholes could become larger and/or some new holes may appear in your tank. If these holes are indeed larger than a head of a pin, now is the time to repair them with NuMetal Epoxy Putty. (See more info below.)

IMPORTANT: ALLOW TANK TO COOL TO ROOM TEMPERATURE BEFORE PROCEEDING. DO NOT ATTEMPT TO SEAL WHILE TANK IS IN DIRECT SUNLIGHT!

Step #3 - Tank Sealer - Sealing The Tank

1) It is recommended to seal your tank within 10 days of cleaning & prepping it. When ready, open Tank Sealer and stir can thoroughly. Touch bottom & lift when stirring to raise & disperse any settled silver pigment. DO NOT WHIP OR SHAKE can as this will introduce air, create bubbles in the Sealer and adversely affect the sealing process.

2) Carefully pour entire contents of can into tank and slowly rotate and roll tank until all sides are evenly coated. Patiently work with sealer for up to 30 minutes. Please note that our Tank Sealer is formulated for use as a single thin coat application so make sure you take the time to thoroughly coat the entire tank well paying particular attention to leaky weld seams & pinholes for optimal coverage & seal.

3) IMPORTANT: After a thorough coating inside of tank, patiently DRAIN ALL EXCESS SEALER from tank until it no longer drips sealer. Additionally, to avoid puddling and pooling of excess sealer inside the tank, rotate the tank side to side every 5 minutes. This step is especially IMPORTANT if design of the tank makes complete draining difficult. This additional rotating of the tank will help minimize excess accumulation in any single area, and result in a slightly thicker coating on ALL walls inside the tank. Foaming and bubbling are signs of excessive Sealer accumulation and gas entrapment due to ineffective drainage. In some cases, this may cause the Sealer to not cure/adhere properly and eventually break loose. Be aware that if this situation should occur, the only recourse is to strip the tank and repeat the process.

4) Immediately use any left-over Sealer for exterior painting and patching to reinforce repair of pinholes & weld seams. (see further patching info below)

5) Immediately remove any excess Sealer from threads and fuel lines before curing. Cured Sealer cannot be removed by any solvent. When job is complete, place drained Sealer in can with lid off and let harden. Drained Sealer cannot be saved & re-used as it has been exposed to atmospheric conditions and will cure & harden in the can. (WARNING: Do not put lid on can before curing is complete as pressure may build within can and pop lid. Dispose of any hardened Sealer properly in accordance with federal, state, and local regulations.)

6) Allow tank to air-dry naturally in a well-ventilated area. IMPORTANT: DO NOT PLACE TANK IN DIRECT SUN OR NEAR DIRECT HEAT. Heating the tank will NOT allow sealer to cure quicker and may in fact hinder adhesion. Allow 96 hours for maximum cure. Always test the tank with water before re-filling with fuel.

Exterior Tank Patching (If Necessary)

Use KBS BackBone Reinforcing Mesh for exterior repair of pinholes or weld seams. Prior to patching, prep the outside and inside of the tank by using KBS Klean and RustBlast and allow all surfaces to dry completely. Begin by sealing the inside of the tank as outlined above. After sealing, immediately use any remaining Sealer to paint a thin layer on the exterior pinhole area(s). Using a suitably sized piece of BackBone Mesh, embed it directly into the wet Sealer and apply another thin coat of Sealer painting outward from the center. Let cure.

For exterior patching of holes that are larger than pinholes, use KBS NuMetal Epoxy Putty. Clean & prep the inside and outside of the tank using KBS Klean & RustBlast as stated above. Let dry. Scuff up area to be patched with 320 grit sandpaper then follow NuMetal application instructions. (NOTE: Allow NuMetal to cure for 12 hours before proceeding with sealing the inside of the tank.) After sealing & draining the inside of the tank, immediately use any remaining Sealer to paint a thin coating on the exterior patched area for reinforced coverage.

Clean Up

Use KBS #1 Thinner for immediate clean up. IMPORTANT: Gold Standard Tank Sealer must be cleaned up before it dries as it cannot be removed by any solvent once cured. Always wear protective gloves to avoid skin contact and temporary staining. If skin contact accidentally occurs, immediately remove with #1 Thinner or lacquer thinner followed by soap and water. If Gold Standard should stain your skin, only the course of time will remove it.

Stripping (If Necesary)

Use KBS Strip (or a paint stripper containing Methylene chloride) for the most effective removal of an old failed coating. Pour some KBS Strip into tank and carefully rotate tank to allow contact with all sides. It may take multiple applications of KBS Strip to finish the job completely. Old Sealer may come loose in big chunks or small pieces so use a long tweezers-type tool to help remove it from the tank. After stripping is complete, rinse tank generously with water and proceed with the KBS 3-Step System for Fuel Tank Preparation & Sealing. (NOTE: When stripping a Fiberglass Tank, surface contact with the stripping agent should be kept to a minimum to avoid the attack & weakening of the fiberglass resin.)

NOTE: Extra care needs to be taken when using KBS Strip to avoid contact with exterior paint of a tank. KBS Strip is a powerful paint remover and WILL INDEED remove exterior paint on gas tanks.

Fiberglass Tanks

The procedure for sealing a Fiberglass Tank is the same except for a variance in Step #2 - RustBlast. For this type of tank, thoroughly wet the fiberglass surface for only 2 minutes using RustBlast. Drain and rinse well with water as directed. Because you are not prepping metal or dissolving rust, RustBlast may be saved and re-used for future use. RustBlast will, however, treat the fiberglass surface by giving it a more acidic pH level & by leaving a zinc phosphate coating ideal for Sealer adhesion.

Also, it is important to make sure that the tank is completely dry inside before sealing. Drying is best accomplished by introducing forced air into the tank by using a shop vac, blow dryer, or fan. (NOTE: Drying is a critical step for sealing fiberglass tanks. Fiberglass tends to hold moisture and if the tank is not dried completely, the Sealer will not adhere properly.)

IMPORTANT: It is also very critical to methodically coat the entire fiberglass tank completely & thoroughly with the Sealer. If any part of the fiberglass surface should accidentally be left exposed or unsealed, however, these unprotected areas will be very susceptible to deterioration by alcohol blended fuels and it is therefore highly recommended that these fuels not be used in fiberglass tanks even after sealing. After coating the tank, remember to drain well to avoid pooling and puddles.

NOTE: In the unlikely event that you would have any troubles with the KBS Tank Sealing Process, we have our KBS Fix-It Guides Available HERE. It is always a great idea to familiarize yourself with these guide before you begin your project.

Questions & Tips

Q. Does duct tape provide a sufficient seal to allow you to rotate, turn & invert the tank without the Sealer spilling all over the place?
A. Yes, duct tape or electrical tape works well. Also, a piece of cork or rubber will seal small tubes.

Q. What’s the best way to prevent the Sealer from getting on the screw threads?
A. Apply a small amount of oil (WD-40 or similar) to the threads, and if the Sealer dries on those threads, it will peel right off.

Q. What’s the best way to remove the Sealer from the fairly small "L" shaped protrusions on the underside of each side of the tank?
A. If you can’t get to it from the inside, use pipe cleaners or cotton swabs to remove the Sealer from these tubes before it cures.

Q. Any other tips, "tricks of the trade", suggestions, etc.?
A. Just remember to be sure the tank is completely dry before using the Sealer. Apply a thin film of oil wherever you don’t want the Sealer to stick. Do not allow the Sealer to "puddle" in the tank. If the tank has baffles or a design which does not allow for complete draining of the excess Sealer, keep rotating the tank (every 10 min or so) as the Sealer cures to help prevent pooling & puddles.

Video - Sealing a Gas Tank

Learn how to seal up a Motorcycle Gas Tank with the KBS Cycle Tank Sealer Kit which gives you everything you need to seal a tank of up to 5 gallons.

Video - Sealing a Car Gas Tank - Part 1 of 4

Covers tank removal & fuel tank repairs.

Video - Sealing a Car Gas Tank - Part 2 of 4

Covers degassing the tank and welding any holes that are larger than pinholes.

Video - Sealing a Car Gas Tank - Part 3 of 4

Covers cleaning the tank with KBS Klean and etching the tank with RustBlast.

Video - Sealing a Car Gas Tank - Part 4 of 4

Covers sealing the tank with Gold Standard Tank Sealer.