Custom Shop 1K High Build Primer Spray Paint - 12 oz Grey, Fast-Drying Sandable Automotive Primer

Custom Shop 1K High Build Primer Spray Paint is a 12-ounce grey, fast-drying automotive primer that fills minor imperfections and bonds to metal, plastic, and fiberglass to create a smooth, sandable base for topcoats.

Whether you're restoring a classic, prepping a replacement panel, or refreshing wheels and trim, this high-build 1K primer delivers a uniform foundation that simplifies sanding and improves final paint adherence. Formulated for direct-to-metal use and engineered to stick to a wide range of substrates, it reduces prep time while producing professional-looking results from a convenient aerosol can.

How well does this primer adhere to different surfaces?

The Custom Shop 1K primer has a versatile adhesion profile designed for automotive restoration work. It bonds strongly to steel, aluminum, fiberglass, SMC, urethane paints, and many plastics, so fewer adhesion steps are needed before topcoating.

• Direct-to-metal properties eliminate extra etch steps on many surfaces.
• Works on both flexible and rigid substrates, including wheel and trim areas.
• Recommended for steel, aluminum, fiberglass, SMC, and properly prepared urethane finishes.
• Provides a consistent surface that accepts a wide range of refinish topcoats.

What finish and sanding characteristics can I expect?

This high-build formula lays down a filling coat that evens out small imperfections and pinholes. After curing, it sands smoothly to create an even profile for primer-surfacer or color coats, reducing the need for multiple heavy skim coats.

• High build fills minor scratches and orange peel for a flatter sanding surface.
• Sandable texture that responds well to block sanding and spot repair techniques.
• Grey tone gives good contrast for identifying low and high spots during prep.
• Fast-drying aerosol format speeds through multiple repair stages.

How easy is it to apply and cover with the spray can?

The 12-ounce can features a flat fan high-atomization nozzle that creates a broad pattern for quick, even coverage. Multiple light passes produce consistent build without runs, making it suitable for panels, trim, and smaller repair areas.

• High atomization nozzle for smooth, wide-spray laydown and fewer strokes.
• Convenient 12 oz size fits tight jobs and touch-ups without waste.
• Drying profile supports rapid recoat and sanding workflows.
• Compatible with typical shop topcoats when fully cured and prepped.

Will this primer work with my chosen topcoat?

Custom Shop 1K High Build Primer is formulated to accept most automotive refinish topcoats once it has been allowed to cure and is properly sanded. It creates a neutral grey base that helps hide minor defects and improves color uniformity of the final finish.

• Grey color ideal under both light and dark topcoats for consistent coverage.
• Suitable as a primer-filler layer prior to basecoat/clearcoat systems.
• Self-etching properties improve metal adhesion when applied correctly.
• Follow paint maker instructions for any required adhesion promoters or sealers.

This spray primer is built for hobbyists, DIY mechanics, and professional body shops that need a reliable, easy-to-use foundation coat. If you restore cars, repair panels, refinish wheels, or handle trim work, the Custom Shop 1K High Build Primer gives you a robust, sandable surface that streamlines preparation and helps achieve a cleaner final paint job. Always follow surface preparation and safety guidelines for best results.