Sanding a repair...

Hi all,
So ive tackled the repairs, the first few were awful but the later ones ok. What im struggling to understand is how to sand them down properly.
So ive added 2 layers of cloth and resin in a taped area. Remove the tape and i have a nice 'raised patch' from my repair. If i try to sand the edges im inevitably going to take some layers of the board near the edge of the repair.
So, do i sand the arse out of the repair so it is flat with the board, then paint a bit of resin on and wet sand that. Or do i sand the repair down as best i can without sanding the original board and wet dry the edges making as minimal a bump as possible?
Help needed ASAP. Im driving to Sennen on friday and have about 8 patches to finish!
Dan
So ive tackled the repairs, the first few were awful but the later ones ok. What im struggling to understand is how to sand them down properly.
So ive added 2 layers of cloth and resin in a taped area. Remove the tape and i have a nice 'raised patch' from my repair. If i try to sand the edges im inevitably going to take some layers of the board near the edge of the repair.
So, do i sand the arse out of the repair so it is flat with the board, then paint a bit of resin on and wet sand that. Or do i sand the repair down as best i can without sanding the original board and wet dry the edges making as minimal a bump as possible?
Help needed ASAP. Im driving to Sennen on friday and have about 8 patches to finish!
Dan