Mercury - Quicksilver 8M0172754 Corrosion Guard Engine Protect Rust Inhibitor Spray 12 oz 8M0172754. Overview. Every boater knows that corrosion is a quiet enemy. It works slowly, slipping into the places you rarely look - around powerheads, brackets, and hidden metal edges under the cowl. That's why I keep Quicksilver Corrosion Guard Engine Protect 8M0172754 in my dock box and on my workbench. One quick spray before or after a run gives me the same calm, steady confidence I get when my engine f