REMOVING THE ROT
1 Raise and secure the rear of the car on axle stands (a ramp is shown here) and remove the road wheel. Remove or protect any trim that could be damaged when grinding and welding, including arch trims and as shown here, the rear bumper.
2 Use a screwdriver and steel wire brush to inspect the extent of the rust around the inner and outer arches. If you’ve already bought your arch repair panels, check if the rust extends beyond them.
3 If the arch is full of filler, try to sand this back with an angle grinder to see the extent of what needs replacing. The arch on this MR2 contains filler and brazed repairs, which must be cut out.
4 Trial fit the arch repair panel and secure it with vice grips. Use a permanent marker pen to draw around the arch repair panel. This will act as a guide when removing the old metal.
5 Use an air saw to carefully cut a line around the old outer arch. Avoid cutting into the inner arch and don’t go beyond the line drawn in the last step.
6 After cutting through the outer arch, it cannot be removed until the spot welds are ground off it, which attach it to the inner arch. These can usually be found along the wheel arch lip.
7 Once the spot welds along the lip of the arches have been ground off, the outer arch can be peeled off the inner arch. Watch your fingers as the metal will be sharp.
8 With the outer arch removed and the inner arch exposed, inspect the condition of the inner arch. It needs to be rot-free to weld the outer arch repair panel to it.