Rain Repellent for Glass: How It Works and Why You Need It
In heavy rain the wipers can't keep up, and side windows and mirrors don't have wipers at all. A hydrophobic coating solves this problem. Here's how it works and when to apply it.
A summer downpour in Tbilisi, a night drive through the mountains, wet snow in winter on the Gudauri road. The wipers are on full speed, and you still can’t see well. Side windows and mirrors are covered in droplets, so changing lanes means driving almost blind. Rain repellent on the windshield and mirrors solves this problem.
Rain repellent is a hydrophobic coating for glass. Water doesn’t spread into a film on it. Instead, it beads up and gets blown off by the airflow.
How a hydrophobic coating works
Glass only looks smooth. Under a microscope it has pores and irregularities where water gets trapped. That’s why droplets spread out and turn into a cloudy film.
The coating fills these pores and levels the surface. Water can’t hold on, it gathers into beads and rolls off. On the highway, the wind clears droplets off the windshield almost without the wipers.
Where rain repellent is needed most
- Side windows and mirrors. There are no wipers here, yet you need to see clearly every time you change lanes.
- Windshield. Less load on the wipers and better visibility at night in the rain, when oncoming headlights glare off the wet glass.
- Rear window. Especially useful on cars without a rear wiper.
SOFT99 rain repellent: how studio application differs from store products
The product itself covers only half the job. The other half depends on how the glass is prepared. Before application, the glass must be cleaned of film, residue and silicone traces from the wipers. If this is skipped, the coating will leave spots: water will bead in some places and sheet in others.
We use the SOFT99 product from the Japanese brand and clean the glass before application.
How to tell it’s time to renew rain repellent
The lifespan depends on how much you drive and how often you use the wipers: the coating wears off faster on the windshield than on side windows. It’s easy to tell when it’s time to renew: water starts to spread out again instead of beading up.
To extend its life:
- wash the glass with car shampoo, without aggressive chemicals;
- replace old wiper blades that squeak or leave streaks;
- don’t run the wipers over dry, dirty glass.
Rain repellent and paint ceramic coating
The principle is similar: a smooth protective layer that water rolls off. The difference is that ceramic coating is designed for the car’s paintwork and lasts for years, while rain repellent is for glass. They are often applied together, after polishing, so the whole car is protected.
Price
Rain repellent at Detailing Standart costs 50 ₾ for a car of any class. It can be added to any service: polishing, interior cleaning or detailing wash. All prices are in the calculator, and a comparison of services is in the article how much car detailing costs in Tbilisi.
