SEM Self Etching Primer Aerosol - Black 15.5 oz | Metal Adhesion, First-Step

SEM 39673 Black Self Etching Primer is a 15.5 oz aerosol primer formulated to deliver the first-step etching adhesion layer for bare substrates before topcoating.

This self-etching primer from SEM is designed as the initial coat to improve the bond between bare surfaces and subsequent paint layers. Supplied in a convenient 15.5 oz aerosol can, it simplifies preparation for repair, restoration, and refinishing work by creating a chemically active surface that promotes strong adhesion on metals and other unpainted materials.

What surfaces does this primer help prepare?

SEM 39673 is intended for use on bare substrates where direct adhesion of a finish coat can be challenging. It’s commonly selected for uncoated metal and similar materials that require an adhesion-promoting base layer.

• Suitable for bare metal and other unpainted substrates.
• Functions as the first-step etching primer prior to sealer or topcoat.
• Helps reduce the risk of premature paint failure on untreated surfaces.

How should I apply the 15.5 oz aerosol for best results?

For consistent coverage, apply the aerosol in controlled, overlapping passes and allow the primer to flash between light coats. Keep the can moving to avoid runs and build up a uniform film before topcoating with compatible products.

• Shake the can thoroughly before use to mix contents evenly.
• Apply multiple light coats rather than one heavy coat for even adhesion.
• Allow recommended flash/dry time before sanding or overcoating.

Can this primer be used under my regular paint system?

Yes—SEM self-etching primer is formulated to be a preparatory layer that improves the bond of sealers and finish coats. Always confirm compatibility with your chosen topcoat and follow any manufacturer guidance for sanding or sealing steps.

• Acts as a base coat to enhance topcoat adhesion on bare materials.
• Works best when followed by appropriate sealer or finish products.
• Check product data sheets for specific compatibility and overcoating windows.

Who is this for? SEM 39673 Black Self Etching Primer in a 15.5 oz aerosol is aimed at automotive and industrial refinishers, technicians, and DIYers who need a reliable first-step primer to improve adhesion on bare substrates. If you frequently prepare unpainted metal or similar surfaces and want a portable, easy-to-use etching primer before applying sealer or color coats, this aerosol offers a practical solution.