Using POR-15
Short answer: For the smoothest finish and best adhesion, sand- or bead-blast the parts first (if you media-blast, you can skip the separate metal prep). On parts you can only wire-brush or sand, use POR-15’s metal prep to etch and kill the rust.
Tips from experience:
- POR-15 used as a topcoat discolors under UV light — fine for hidden under-car parts, but exposed pieces like a subframe will dull over time. Their Chassis Black product avoids this, but spray it; brushing gives poor results.
- Brush marks are a real issue. A foam brush helps (though it eventually falls apart). For a very smooth finish: two coats of POR-15, dust with primer, then after it cures add another primer coat and a final enamel topcoat — this hides POR-15’s imperfections and prevents UV discoloration.
- If a body shop will work on a part you’ve already coated, insist they protect it — sanding debris and overspray from bodywork can ruin the finish and force you to redo it.
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Content last modified: June 13, 2026 at 10:06 am
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