The quality of the epoxy vinyl FRP resin primer construction directly affects the bonding force between the FRP structural layer and the steel substrate. If the primer construction is sloppy, it will easily affect the adhesion of the coating, cause air bubbles, and may even peel off the entire layer of FRP.  

For basic repair, on the basis of laying a good foundation, repair and fill the unevenly recessed vinyl FRP resin (resin plus an appropriate amount of quartz powder), and use glue for the corners to enter the arc transition, and the recess is too deep. Prevent flow, wait for curing, and then flatten with sandpaper to keep the glue surface flat as a whole. Resin glue (resin strengthener 100/4 ratio added after mixing: Quartz powder - 100 250) apply thinly to prevent hanging, 3-5 kg per ingredient.

After the vinyl fiberglass resin mortar is completely cured and dried for 24 hours, apply a layer of resin, wet the 0.18mm glass cloth, and stick it on the first layer. Apply a layer of resin when sticking. The second and third layers are lined in the same way. After curing for 24 hours, finish with resin putty and level the surface. After curing for 24 hours, apply a resin topcoat. After the first coat has cured, a second coat of resin is applied. After curing, the second finish should be checked and confirmed to be free of defects and delivered after acceptance.

The above construction method is called "gap method construction". Although this method has a long construction period, high construction difficulty and high cost, its bonding strength and compressive strength are obviously better than those of continuous glass fiber reinforced plastic resin (one-time continuous paste glass cloth layer) construction.