In rebuilding a Lotus Twin Cam engine, the clutch pressure plate had surface rust on the face which makes contact with the gearbox side of the driven plate.
I took the plate to the local engineering shop, and they told me they could not re-surface it, and to buy a new one.
These plates are not cheap. £138.00 + VAT from Banks = £165.60.
When cleaning up a rusted brand new disc last week, I found that the pitted rust can be easily cleaned from the disk using an small angle grinder blade full face on. The disc came up like new.
I used the same method on the face of the clutch pressure plate, and it removed all the pitting, and also came up like new. Each plate I resurface saves me £165.60. It only takes about 2 minutes, and a very steady hand, but the guard has to be removed from the small angle grinder, so you have to be very careful.
Alex in Norfolk.