The surfaces must be clean and free of dust and grease. Cut off the tip of the cartridge, screw on the cannula and cut it to match the required bead width. Joint dimension The joint has to be designed according to the sealant movement capability . In general, the joint should be between 5 and 25mm wide. The ratio of width to depth will depend on the joint width. In general, for joints wider than 10mm, the width/depth ratio shoud be approximately 2:1 respectively. For smaller joints, the ratio should be approximately 1:1