POR-15 Application
Short answer: POR-15 works well on the undercarriage, firewall, and frame, but it isn’t as foolproof as advertised. The surface must be completely oil-free (it can have solid rust) — don’t use petroleum solvents like lacquer thinner, or it won’t stick. Etch bare metal with a metal prep and scuff any remaining paint. Brush or spray, and recoat in about 4 hours, when the finish is dry but still tacky.
A few cautions: if you spray, mask everything within 10 feet — the overspray sticks forever. You can’t remove POR-15 once it’s dry, you must recoat on its schedule (not yours), it burns if it gets in your eyes, and the dried gloss can be inconsistent (reportedly typical).
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Content last modified: June 13, 2026 at 10:06 am
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