KBS Fusion SEP - Self-Etching Primer for Bare Metal & Inter-Coat Applications

Yes. Fusion SEP bonds to fully cured RustSeal — even if the RustSeal has been in place for months or years. Simply apply a thin covering coat of Fusion SEP over the cured RustSeal surface, allow 1 hour to dry, then topcoat as desired. No need to strip down to bare metal first.

Fusion SEP is dry-to-touch in 15 minutes and ready for topcoat in 1 hour. No sanding is needed if you apply your topcoat within 24 hours. If more than 7 days pass before topcoating, lightly scuff the surface with 300-grit sandpaper to ensure proper adhesion.

A single light, covering coat is generally all that is required. Additional coats can be applied as needed. When applying multiple coats, allow 3 to 5 minutes of dry time between each coat and use steady, even strokes.

Fusion SEP can be applied by brush, roller, or sprayer, and is available in a convenient aerosol. For spray gun applications, use 35–45 psi for siphon/pot guns or 25–35 psi for gravity/top container guns, with a recommended tip size of 1.0–1.2. For aerosol, shake the can for at least 1 minute and hold the nozzle 10–14 inches from the surface. Always apply thin, even covering coats.

No, Fusion SEP is not a high build primer. It is formulated as a thin, self-etching adhesion primer — its job is to create a tenacious bond between surfaces, not to fill imperfections or build thickness.

No, Fusion SEP is not designed for flexible surfaces. Applying a rigid primer to a flexible substrate can lead to cracking and adhesion failure over time.

Fusion SEP is available in five sizes to match any project scope:

• Aerosol — covers up to 35 sq. ft.
• Pint — covers up to 50 sq. ft.
• Quart — covers up to 100 sq. ft.
• Gallon — covers up to 400 sq. ft.
• 5-Gallon Pail — covers up to 2,000 sq. ft.

Thinning is generally not required. If thinning is needed, use KBS #1 Thinner only at a ratio of 5–10%. Do not reduce Fusion SEP with lacquer thinner — lacquer thinner may only be used for spray gun and tool cleanup, not for thinning.

The recommended application temperature range for Fusion SEP is 55–82°F (13–28°C). Once fully cured, Fusion SEP can withstand temperatures up to 250°F.

You should topcoat over Fusion SEP within 7 days of application. No sanding is required if you topcoat within 24 hours. If more than 7 days have passed, lightly scuff the cured surface with 300-grit sandpaper before topcoating to ensure proper adhesion.