Providing a transverse filling inside and elongated narrow cavity

A method for performing a task in a tight place in an elongated profile, preferably in a wing blade with an outer shell for a wind power plant, where the task is preferably a retrofit task whereby there is formed at least one barrier transversely of at least one elongated channel in the profile, wherein the method includes the following steps:

• establishing a number of inspection and mounting holes in the shell, preferably small, drilled holes with a diameter between 8 and 25 millimetres and preferably with a diameter between 10 and 12 millimetres;
• providing one or more inflatable balloons in the channel in question, where a balloon is passed through one of the established holes;
• inflating the balloon or balloons, preferably with atmospheric air;
• applying at least one first material layer which extends between the sidewalls of the elongated channel and across the balloon or balloons, where the layer preferably is expanded polyurethane foam, wherein the method further includes a step wherein an additional material layer is laid upon the first material layer, where the additional material has a specific density and/or strength which is greater than that of the material laid at first.