Tech Tips: Sealing Edges When using Carbon fibre products, wether it be TVP's, Chassis, Disc brakes or shock towers, always seal edges with thin Ca. Some use a Q tip, others will drop a small dab on the edge and let it run down only adding as necessary while rotating part. This is a little more risky way of doing it, however you will get thicker coverage. Once Ca (Zap a gap) has been added and has dried, take a fine emery cloth or file and take off all the sharp edges. This requires very little pressure, just enough to break the corners of the edges. These sharp edges can cut skin, fuel lines and wires..