SEM Products Undercoating

Professional-Grade Undercoating from SEM Products

SEM Products has been a trusted name in automotive coatings since 1948, and their line of undercoating products reflects that decades-long commitment to professional performance. Whether you're protecting a daily driver, restoring a classic, or maintaining a commercial fleet vehicle, SEM's undercoating formulas deliver the triple-threat performance that matters most beneath your vehicle: corrosion resistance, chip protection, and sound dampening.

A Range Built for Real-World Conditions

SEM offers several distinct undercoating formulas to match different application needs and regional environmental regulations. At the core of the lineup is the classic Rubberized Undercoating — a paintable, single-component, textured coating engineered for sound dampening, chip resistance, and rust and corrosion protection. Unlike many traditional undercoats, this formula is 100% asphalt-free, meaning it won't bleed through a topcoat and dries quickly for fast turnarounds in professional shop settings.

For shops and DIYers in stricter regulatory environments, SEM's Low VOC Rubberized Undercoating delivers the same premium, asphalt-free protection while meeting VOC compliance standards below 40% — making it suitable virtually everywhere. It's available in both aerosol cans (complete with a straw for hard-to-reach tight spots) and larger liquid formats for gun application.

For those who prefer a traditional asphalt-based formula, SEM also offers a standard Undercoating and a companion Low VOC Undercoating. These non-paintable, asphalt-based products are formulated to provide excellent sound dampening, chip resistance, and outstanding corrosion protection on frames, wheel wells, and undercarriage areas.

What Sets SEM Undercoating Apart

• OEM Recommended: SEM's rubberized undercoating formulas carry OEM recommendations, making them a trusted choice for collision centers and restoration shops alike.
• Paintable Without Bleed-Through: The rubberized line is pinhole-free and paintable, giving technicians flexibility to finish the job cleanly.
• Broad Surface Compatibility: SEM undercoatings adhere to properly prepared steel, aluminum, SMC, and fiberglass surfaces.
• Low VOC Options: Compliant formulas are available for all regions with strict environmental regulations, without sacrificing performance.
• Application Flexibility: Aerosol cans provide easy DIY use; larger liquid containers pair with SEM's Economy Coating Gun or Premium Undercoat Applicator for professional-volume work.

The SEM System Approach

One hallmark of SEM's philosophy is the system approach to coatings. Their undercoating products are designed to be used alongside SEM Solve surface cleaner for proper prep, ensuring maximum adhesion and a long-lasting protective barrier. This attention to the complete repair process — from surface preparation through final protection — is a big reason why professional technicians and collision repair facilities have trusted SEM for generations.

Explore the full range of SEM Products undercoating options to find the right formula for your next restoration, rust-proofing, or sound-deadening project.