4. Turn the sail and check if the Dacron is glued in the centre. If it is needed, the Dacron can be moved for some time before it hardens.

5. Cut a piece of Velcro from the soft side (the part of hard Velcro that serves as a the spine tunnel is already there) with a length of 120mm and 25mm wide.

6. Glue the piece of Velcro between the Dacron and the sail. It is positioned against the bottom of the spine tunnel.

7. Mark the sewing line on the fortification.

Watch Out: On the bottom mark the sewing line at 5 mm from the bottom of the trailing edge by which the leechline can pass freely (red lines). The rest of the sewing line is drawn at 1 to 1,5 mm from the border of the fortification (yellow lines).

8. Mark the bottom of the fortification at 1 to 1,5 mm from the bottom of the trailing edge and from the border of the fortification.

Watch Out: Make sure you don't put marks on the trailing edge.

9. Sew the fortification and the Velcro with a straight seam. Start at the bottom point (between the red lines). The bottom part is sewn in a triangular shape, double.

10. Sew the bottom part.

11. Take the mould for the fortification for the Central-T and tape this to the Dacron.

12. Cut the hole for the Central-T with a fine cutter.