1. Brush off any rust or foreign particles. Wipe flange surface thoroughly with a rag soaked in acetone or other suitable solvent to remove grease or oil.
2. Insert fingernail between the paper backing strip and the tape and strip the paper back three to six inches. Draw a reference line in flange and press squared off end of tape against it.
3. Now, start laying the tape along the face of the flange, peeling the paper backing as you go. To prevent the adhesive surfaces of the tape from doubling back on themselves and sticking together, strip away only a few inches of paper at a time.
4. When the starting point has been reached, lap the tape not more than 1/16 inch and cut with a sharp blade.