Aqueous solutions of inorganic nitrate salts are used to accelerate the gelling of epoxy gelcoat resins without adversely affecting the glass transition temperature of the finally cured gelcoat. The method defines a set of partitioning lines for partitioning the region into a plurality of sub-regions during a placement operation. A spring element is arranged in the active area between the clamping section and the grip section in order to achieve improved proportioning of the clamping force, whereby both grip sections can be disposed on top of each other and placed in another locking position, when both clamping sections are maintained in a distanced position, in order to increase clamping power.