If you’re unsure about tackling a panel replacement right away but need a temporary fix for rusted metal, try All-Metal body filler. It’s like Bondo on steroids and actually has aluminum flakes suspended within the filler substrate. On Eastwood’s website, it’s recommended for use on damaged or rotted out sections of metal and is described as a safer alternative to lead filler. Be sure to clean all the excess rust from the area and treat with a rust converter first. Mix the All-Metal with its hardener, just as you would with regular body filler. Apply it with a spreader and allow it to dry before sanding it smooth. We’ve used this before and can attest to its strength. This is tough stuff and takes forever to sand. Get the 40-grit (or even 36-grit!) paper out for this.