Fixing A Windscreen Chip

The worst thing about winter is that the roads get gritted. You are behind a gritting lorry and you can hear your car getting dashed with rock salt. The next problem is the grit and salt being kicked up and damaging your windscreen.

If you leave a crack like this, it will get bigger and eventually the screen will crack or it’ll fail a vehicle test.

Why Do Cracks Get Worse?

The cracks may be small but water is smaller. Like almost all materials, glass and water expands and contracts as the temperature changes. So, water gets into the crack and can freeze. In the freezing temperatures, water turns to ice which expands and glass contracts. The opposing forces in the crack causes the crack to elongate.

The other problem is that water draws in tiny particles of dust. The dust compacts so when the glass tries to contract, it has nowhere to go. The pressure increases until the glass cracks even more.

Repairing The Crack

Essentially yes, we are repairing the crack but what we are really doing is sealing the crack. This stops the water and dirt getting into the crack so it won’t get any bigger. Don’t think for a second that this fix will make the crack disappear. It’ll be better but still be visible.

What Kit Should I get?

There are some very complcated kits with frames and suction cups. They are generally more expensive and really not as good as the cheaper kits. This is the kit I used.

It consists of a double sided sticky O, a plastic attachment, a bottle of resin, a syringe, plastic sheets and a blade. Firstly, clean the crack. Pick it with a pin and spray it with brake cleaner and let it dry.

Remove 1 side of the sticky O and stick it to the windscreen so the chip is in the centre.

Peel off the top to reveal the other sticky side.

Place the plastic piece so the nozzle faces upwards.

Open the resin contain and place 6 drops of the resin into the hole.

Make sure the syringe is pushed all the way in before securely fitting it to the screen.

Pull the syringe up until it locks into place. What is happening here is the syringe is creating a lower pressure. This draws out any air that is trapped in the crack. If you didn’t do this, the air would just be trapped under a layer of resin.

Hey Siri, set an alarm for 10 minutes.

After the 10 minutes, remove the syringe and pull the plunger all the way back.

Refit the syringe and press the plunger down a third of the way and it should lock in place again. What is happening here is the syringe is creating a pressure build up to help push the resin into the crack.

Alexa, set an alarm for 20 minutes.

After the 20 minutes, pull of the plastic and use the razor to remove the sticky backed O.

The resin will still be liquid. WTF! After 30 minutes you’d expect it to have set right? Nope, I’ll explain in a bit.

Place a couple of drips of the resin onto the chip…

…and place on of the plastic sheets over it. You should see no air bubbles in there at all. If you do, massage the air bubble out and maybe add more resin if you think you need it.

Wheel the car outside. OK Google, set an alarm for 1 hour.

You see, this resin sets through ultra violet exposure so 1 hour in outside is enough to set it. Of course you could just cheat like I did and use a UV torch for 5 minutes.

Peel off the plastic…

…and cut away the excess resin by scrapping the screen. Don’t worry, you won’t damage the glass.

You are done. The crack will still be visible but should be better and won’t crack.

You can add more resin, add the plastic sheet and allow it to set another time if you think it’ll improve it.