One is the inlay method. Firstly, mark the damaged part on the building membrane board, measure its size, prepare 4mm thick rectangular plywood according to the size, and then use the embedded rectangular plywood and put it on it.
The other is the polyurethane material filling method. First, the groove on the surface of the coated plate shall be made to determine the size of the damaged part, then the groove around the damaged part shall be cut into 4mm, and the coated plate around the groove shall be cut with a chisel or knife to remove all loose parts and clean them. Mix the polyurethane and curing agent, and mix them at the rapid curing ratio of 15 minutes curing, then pour the resin, curing agent and mixture into the area to be repaired, and check whether there is air in the mixture with a needle.
It should also be noted that the resin, curing agent and mixture must have a liquid level higher than the edge of the repair area. After the resin is completely cured, the resin surface shall be polished and polished with a grinder.
