TAKE YOUR TIME WITH THIS STEP! Winding the hull to achieve fairness (no lumps, or bumps) can be achieved by suspending the kayak from the rafters on ropes thereby eleminating any undue pressure in unwanted places. Lay a 4! level perpindicular to the kayak first on one end, then check for level on the opposite end. You will be able to detect any twist by doing this. If you detect any twist, loosen the stiches and make necessary adjustment before tightening the wires. A string streched from the exact center of the bow to the exact center of the stern will provide a base line to measure from to help checking for fairness. It still requires an "eye" for fairness but these suggestions may help. Good luck!