Why your windscreen wipers still smear despite new blades

You've just fitted brand new wiper blades, but the windscreen still smears the moment it drizzles. The problem usually isn't in the blade - it's in the glass.

New blades only solve half the problem

A wiper blade is essentially a rubber edge that should draw water evenly across a smooth surface. If the surface under the rubber isn't smooth - but instead covered in an invisible layer of road film, old wax residue, insect residue and minerals from screen wash - the blade has no chance. It doesn't matter how new the blade is if it's gliding over an uneven film instead of clean glass.

That's why so many people find that new wiper blades smear just as badly as the old ones after only a week or two. The solution is to tackle the glass surface itself, not just the blade.

Step 1: Proper glass cleaner - not just window spray

Regular household window cleaner is rarely designed to break down road film and old wax residue in the same way as a dedicated glass cleaner for cars. A good glass cleaner dissolves grease and build-up without leaving an oily film that later attracts more dirt.

• Clean the window both inside and out - smearing and hazing form from the same type of build-up on the inside.
• Use a microfibre cloth used only for glass.
• Check the result in back-light - if you see streaks or a grease film, you haven't removed enough.

Step 2: Glass polish removes what the cleaner misses

Sometimes cleaning isn't enough - especially if the windscreen has scratches from old wiper blades, mineral etching or really ingrained road film. That's where glass polish comes in. A glass polish contains lightly abrasive particles that microscopically level the glass surface, remove light scratches and eliminate the last traces of build-up that a regular cleaner can't handle.

Polishing is best done with a soft applicator or a polishing machine at low speed, followed by a fresh clean to remove any polish residue before the next step.

Step 3: Glass coating makes the effect last

Once the windscreen is completely clean and smooth, it's worth sealing it with a glass coating. Such a treatment makes the glass water-repellent, which means dirt, insects and road film have a harder time adhering in the first place. The result is that the wiper blades have a smoother surface to work against for longer, and smearing takes significantly longer to return before it's time to clean again.

Remember that a coating only holds what it promises if the prep work - cleaning and possible polishing - has been done properly. Applying a coating to a dirty windscreen is like waxing a floor full of grit.

Don't forget the wiper blades and arms

Even with a perfect windscreen, old wiper blades can cause smearing. Clean the rubber edge of the blades with a cloth dampened with glass cleaner at regular intervals, and check that the wiper arm's spring pressure is even across the whole windscreen. Uneven pressure makes the blade scrape unevenly, which is often perceived as smearing when it's actually uneven contact against the glass.

Summary

If the wipers smear despite new blades, the fault usually lies in the glass, not the rubber. Start with a thorough glass clean, complement with glass polish if needed and finish with a glass coating to keep the surface clean and smooth over time. Combined with clean wiper blades, you'll get a windscreen that stays clear - regardless of how much it rains.