How To Fix A Cracked or Chipped Windshield

Replacing a cracked windshield can be very expensive but there are plenty of cheaper alternatives around on the market. Of course, the sooner you can repair a crack the better as a crack that is left alone can soon develop into a much larger irreparable crack.

If you don’t repair a chip or a crack on a windshield this will only cause it to spread and subsequently render the windshield useless. The idea behind repairing a windshield is to prevent the air from getting to the crack so ensuring that its airtight essential. There are now several kits around that will help you repair a cracked windshield most of which follow a very similar process. Most contain an adhesive contained within a syringe which when injected into the chip forces out any air, seals up the surface and prevents further damage from taking place.

So how do we start? Before you do anything measure the crack. Cracks 6 in (approx. 15 cm) or under are fine to be repaired at home. Cracks longer than this up to and including 18 in (approx. 46 cm), consult a professional and check that it’s safe to repair at home. For cracks, longer than 18 in let a professional deal with it. Cracks that penetrate through to the inside of the windshield i.e. can be felt while sitting inside the car should not be fixed but the windshield should be replaced.

So, everything you’re going to need can be bought from your local hardware store all at a fraction of the cost of purchasing a new windshield.

First thing you need is a bridge style repair kit. Ideally one with suction cups are better as it will help “stick” to the window while your applying the resin into the crack. It should also contain a vacuum system that will help remove air from the crack as the resin is applied.

The resin within the applicator will need to be “cured” AFTER it has been applied, with UV light so make sure its daylight, preferably when its sunny, but if this is not possible see if you can get hold of a UV lamp.

Finally, before applying the resin tap out any broken glass or shards that may still be present and ensure that the window is clean and dry. The last thing you want to do is trap any broken glass or dirt into the window.

Once the window is ready, pending on the type of resin applicator you have purchased, you will need to prep the syringe with the resin. Always check the instructions as each one will differ slightly in the application method. If you are dealing with a longer crack, then you will need to make a small hole at the end of the crack but not all the way though just on the surface approx. ¼ the way through. Recommend you use a glass drill bit for this. Once this has done place the loaded applicator over the area that needs to be repaired. If your applicator came with suction cups then you will need to apply a lubricant. Vaseline is ideal for this. If your applicator didn’t come with suction cups then simply hold the end against the crack.

Slowly pull up or release the applicator syringe. This will allow the resin to enter the crack while at the same time forcing out any air that may be in the crack. Do approx. 2 cm at a team before moving the applicator. This is where greased suction cups are ideal as they will slide easily across the window. Take your time as this is the trickiest part and getting this wrong could cost you the window. Once you are sure the resin is entering the crack you will be able to easily move the applicator across and fill the rest.

Once you have filled the crack you will need to apply the curing tape. Sometimes they give you large sheets so cut to size or as required and cover the whole length of the crack. You will now need to leaver the window exposed to UV light to cure the resin. Note you will still be able to see the crack at this point. Curing can take from 30 mins up to couple hours so be patient. Once it has been cured then you can removing the curing strips and using a razor, (some kits provide one), scrape off any excess resin from the windshield. You will still be able to see the crack faintly but for the large part it will be mostly invisible.