Engine Block Sealer And Engine Block Coating

RustSeal and KBS Tank Sealer are excellent engine block sealer options for coating and sealing the inside of an engine block.

Why should the inside of an engine block need to be sealed?

Typically, "sealing an engine" is thought of as using gaskets to seal the surfaces of adjoining fluid-filled engine components to prevent leakage — for example, a valve cover gasket, an oil pan gasket, or a main seal. However, we are referring to sealing the inside surfaces of the engine block.

Sealing the inside of an engine block, often referred to as "block sealing" or "block coating," provides performance, durability, and maintenance benefits by addressing three key problems:

What surfaces are typically sealed with engine block sealant?

• Crankcase
• Lifter valleys
• Other oil return passages

What are important traits of engine block sealer?

Engine block sealer must perform in extreme environments without failing. The following criteria are critical:

• Adhesion — Must bond strongly to metal to create a reliable, long-lasting seal that will not peel off and plug oil filters, pump screens, or oil passages.
• Flexibility — Must handle engine vibrations, thermal expansion, and contraction without cracking or losing its seal.
• Chemical Resistance — Must resist engine oil, coolant, and a wide range of fluids.
• Temperature Resistance — Must withstand high engine temperatures as well as cold temperatures without breaking down or losing sealing properties.
• Compatibility — Must be compatible with aluminum, cast iron, and other alloys.
• Durability — Must provide a long-lasting seal.

Sealing engine blocks with RustSeal or KBS Gold Standard Tank Sealer

RustSeal and KBS Tank Sealer use single-component moisture-curing polymeric isocyanate formulations engineered to strongly bond to and seal metal, creating a smooth, tough, hard yet flexible coated surface. Both are purpose-built for engine block sealing:

• Incredible adhesion to prepared ferrous and non-ferrous metals
• Excellent coating flow out for a smooth finish that improves oil shedding and oil passage flow
• Thorough sealing of porous engine blocks
• Corrosion prevention
• Flexible to allow engine block expansion and contraction with heat
• Impervious to fuels, oils, and chemicals
• Withstands temperatures up to 600°F — more than enough for oil-cooled engines
• Incredibly durable and long-lasting

What is the best engine block sealing procedure?

The interior surfaces of the block must be properly prepared with KBS Klean and RustBlast to ensure strong coating adhesion. Before beginning, block off or plug any areas not to be coated or prepped.

Step 1 — Clean with KBS Klean

KBS Klean is a concentrated cleaner mixed with warm or hot water. Scrub the interior of the block thoroughly to remove all oil, grease, and grunge. Any cleaner residue left on metal can interfere with coating adhesion — KBS Klean rinses completely residue-free.

Full instructions for KBS Klean can be found on the Application Directions page.

Step 2 — Etch and prep with RustBlast

RustBlast is a powerful acid etch, rust remover, and zinc phosphate pre-primer. It effectively dissolves rust, corrosion, metal oxides, and tarnish from most metal surfaces and etches the surface for maximum adhesion of RustSeal and KBS Tank Sealer. Scrub surfaces with RustBlast and a Scotch Brite pad.

Full instructions for RustBlast can be found on the Application Directions page.

Applying RustSeal or KBS Tank Sealer to the inside of an engine block

Both RustSeal and KBS Tank Sealer can be applied with a brush or with spray equipment.

Full application instructions for RustSeal are on the Application Directions page. The same procedure applies when brushing or spraying KBS Tank Sealer in this circumstance.