SEM Flexible Primer Surfacer aerosol 13 oz — fast-dry, high film build for automotive plastics

This flexible primer surfacer streamlines plastic repair and refinishing by combining strong film build with elasticity so topcoats adhere and move with substrate contours. Supplied in a convenient 13 oz aerosol, it reduces preparation time, sands smoothly, and accepts most refinish topcoats for a durable final finish. It is formulated to bond to flexible plastics common in modern automotive exterior parts, helping to prevent cracking and delamination after painting.

How does this primer save time during plastic repairs?

The SEM 39133 arrives ready to spray, so you avoid mixing or thinning steps and can apply a uniform build rapidly. Its quick-dry chemistry allows sanding and subsequent coats the same day, cutting total turnaround time.

• Ready-to-spray 13 oz aerosol — no batch mixing needed
• Dries rapidly for faster sanding and recoating
• High film build reduces number of primer passes

Will it sand and feather easily for a smooth finish?

Yes — the formulation sands cleanly, enabling technicians to shape edges and blend repairs without excessive effort. That predictable sanding behavior helps achieve a uniform surface for primer-sealer or topcoat application.

• Sands to a consistent profile for seamless transitions
• Compatible with standard sanding grits used in refinish shops
• Minimizes surface imperfections before topcoat

Is the primer flexible enough for bumpers and trim parts?

Designed specifically for flexible substrates, SEM 39133 provides elasticity that moves with bumper covers and other pliable plastics, reducing the chance of cracking under stress. It forms a resilient film that supports long-lasting adhesion of refinish topcoats.

• Flexible formulation engineered for automotive plastics
• Helps prevent topcoat failure on moving or impact-prone parts
• Works well on many OEM and aftermarket plastic substrates

What topcoats can you use over this surfacer?

The surfacer accepts most common refinishing topcoats, allowing shops to use their preferred color systems. Proper surface preparation and following the topcoat manufacturer's recommendations ensure optimal adhesion and appearance.

• Compatible with common refinish basecoats and clears
• Follow standard bonding and tack-free times before topcoating
• Test for adhesion on unusual plastics when in doubt

Who is this for: SEM 39133 Flexible Primer Surfacer (13 oz) is intended for collision-repair technicians, autobody shops, and DIY enthusiasts working on bumper covers, exterior trim, and other flexible plastic parts. It suits users who need a ready-to-use aerosol that builds film quickly, sands predictably, and accepts industry-standard topcoats for a professional refinish without complex mixing or long wait times.