When faced with a rusty bolt or nut or other parts that seem corroded together, the secret is time. After spraying a healthy dose of penetrant on the fused parts, give them several hours—or even overnight—to sit while the penetrating oil seeps in. Then use your wrenches to try and loosen the parts. If they refuse to budge, hit them with another heavy dose of penetrating oil and again let them sit for several hours and try again. more