Plastic windshields are extremely durable and less susceptible to breakage of glass windshields. Unlike glass windshields, most plastic windshields are safe when placed under tension. However, finding a spare plastic windshield can be difficult. Fortunately, plastic can be repaired with acrylic solvent cement and plastic polishing compounds.
- Wash the windshield on both sides with hot water and dishwashing detergent. Clean crack well. Use only a 100% cotton cloth to wipe the windshield to avoid scratching the polished surface. Dirt and grease may form a barrier that prevents solvent cement from melting the broken plastic. A crack can continue to split if not properly cemented.
- Tape the area around the crack with painter’s masking tape, leaving a ¼ “edge of plastic exposed around the crack. Solvent cement may scar the finish of a plastic windshield if it spills onto the surface of the windshield. Tape creates a barrier between the windshield and cement.
- Fill the applicator bottle halfway with solvent cement. Acrylic solvent cement works for almost all transparent plastics. Using your thumb and forefinger, apply pressure to the sides of the bottle until the liquid is on top of the bottle. Slightly loosen the pressure. You have now created a vacuum inside the bottle, keeping the cement spilling when you tilt the bottle during the application process.
- Apply a thin strip of cement along the crack in one side of the windshield. Capillarity will cause the cement to be thrown into the crack. After the cement has dried for two hours, remove the adhesive tape. Apply masking tape around the crack on the other side of the windshield, leaving a ¼ “border around the crack. Apply a thin layer of cement and allow 24 hours of drying time to elapse before proceeding to step 5.
- Apply a small amount of buffing compound on a 100 percent cotton cloth. Remove any remaining tape from around the crack. Polish the area around the crack until any residual cement has been polished to. The buffing compound contains abrasives that grind down the residual glue, while still leaving the plastic clear. Wash the windscreen once more, on both sides, with dishwashing detergent. The project is complete.