Sanding chamfered edge of decking boards?
I have an old cypress pine deck 30 sq meters of 70mm boards. The boards have been previously stained a dark brown and I've sanded the flat surface ready for a new colour.
However the boards have a 45 deg chamfer that runs along the length about 5mm wide. There are approximately 750 linear meters to clean if my maths is correct i.e. 80mm spacing over a length of 6 meters and a width of 5 meters double edged.
I can't find a good method of removing the old stain from the chamfered edge other than manual sanding using coarse sand paper but this is taking so long and I'm sanding my finger tips in the process. I've tried a mouse sander but its too big. Have also tried a flap wheel sanding tool but wrecked it in about five minutes.
Can anyone suggest a better method of sanding these edges?