1967 Mustang Parked 30 Years: Floor Pan Rust Repair

Daylight where steel should be. Our $6,500 1967 Mustang fastback has floors rotted clean through after 30 years parked — and this is the stage of rust that kills cars. This is Episode 4 of 8 in our 1967 Mustang barn-find build. We read the rust in its three stages — surface, scale, and penetrating rot — then brace the unibody before a single cut, because a unibody cut unbraced will never close its doors right again. Then we cut back to clean metal, fit reproduction floor pans, and MIG-weld them in with stitch welds only — a continuous bead warps sheet metal beyond saving. Along the way: the copper pipe weld-backer trick, why weld-through primer is largely theater, why coating the backside after welding is the whole game, and why body filler has zero structural strength. Plus an honest look at why modern cars rust so much less — galvanized steel — versus the bare mild steel Detroit used in the sixties. And the non-negotiable safety notes: zinc fume danger, respirators, and fire watch. Running tally on screen: reproduction pans at roughly $250 to $400 each plus materials — and our series-to-date total. Next episode: the $5,000 roadworthy challenge. Chapters: 00:00 The Floor Can't Wait 00:54 Read The Rust 03:08 Cut It Out 04:33 Weld It Right 06:29 The Backside Is The Whole Game 08:30 Solid Ground #Mustang #ClassicCars #RustRepair #CarRestoration #Welding Subscribe to Rust to Road for the full 1967 Mustang barn-find build — new episodes every week.