The waterproof layer of the lap joint should stick (welding) firm, tight sealing, no distortion, fold, curling and blister defects.
Using FN-309 adhesive etc. as joint adhesive and, the water-resistant abrasive cloth, R/R or G/G abrasive cloth as the substrate belts the process of abrasive cloth lap jointing was studied.
Varied types of intersecting joints, including gap joint with positive eccentricity for the circular tubes and overlap joint for the square tubes, were also adopted in the design.
