The online forums are full of tips that didn't work in analogue times. Modern technology offers no advantages over the oral tradition, on the contrary: it ensures the further spread of misconceptions.
For someone who should know, the matter is quite clear. "The best are the ready-made stand paints," says Claudio Fackelmann from the Cabon Clinic ( www.carbon-klinik.de ) on Lake Ammersee. Although the specialist uses a "house mixture" of ground glass in 2-component paint, "you need a spraying system with a special nozzle and also a proper protective carbon mask and extraction at the workplace, which is really toxic." So hobby painters are probably out of the picture. Professional repairs cost around 70 to 100 euros. This is rarely used; in the "clinic", refinishing work tends to be part of larger repairs.
However, with the ready-made paints from "M2" or "Nautix" (available from specialised surf shops), this is one of the few touch-ups that even the semi-skilled hobbyist should be able to do well.

Deputy Editor in Chief surf