How Does The Spot Free Rinse At The Car Wash Work?
A small amount of silicone is sprayed on with the water in order to prevent it from adhering to the paint as it evaporates. It causes the water to bead and roll off instead. You can see the effects of this yourself if you buy a can of spray lubricant like Tri-Flow. Spray some of it onto any painted surface and follow it with water. The water won’t leave spots, but the silicone will leave a film. The concentration you’re getting at the car wash is lower, but there will still be some residue on the paint. It’s a price you pay for the convenience of not having to dry the car with a chamois.
