I have a long 12" crack. IN MY WINDSHIELD, wiseasses!
I was just wondering if I drilled a little hole at the end of the crack, wouldn’t that stop it from spreading more?
Has anyone ever done this?
Drilling holes in glass is is tricky at best. My guess would be that even with the right tools and instructions, a first attempt is 90+% likely to result in shattering the glass.
If the crack is in your car’s windshield and you have comprehensive insurance, check with your insurer as to the local law regarding this as some states preclude any deductible for glass replacement in an automobile. SC, the state I live in, has such a law. Coincidentally, a metal object struck my car’s windshield last week, resulting in two holes, one of them almost through the entire thickness of the pane. The guy’s coming over tomorrow to put in a new windshield and altho I have a $250 deductible, there is no deductible for this.
But the practice of drilling a hole as a “crack-stopper” is sound. It’s often done in the repair of solid plastic windows. If you can drill a round, smooth-edged hole without causing more cracking, it should stop the existing crack.
Another difficulty might be that auto windshields are a sandwich of a plastic sheet between two glass sheets. This might be harder to drill than a solid pane of glass.
I say go for it. The worst that you’ll do is wreck the windshield, which, with a 12 inch crack, should probably be replaced anyway.
Just remember, the most important safety rule is to wear these: safety glasses.
You could try an auto parts store they have a kit to fill in that line. I got one once. A resin is forced into that line & fills it in. ABout $9 a kit
Thanks Norm!
Be aware that your windshield is layered, it has TWO sheets of glass (with a plastic sheet between them.
The type of crack that crawls slowly through the glass is in just one of the sheets. It’s probably in the outside sheet, since that’s the one that pebbles hit.
Once I was able to “guide” a windshield crack so it curved back towards the nearest edge, rather than proceeding straight across the windshield. By pushing on the inner surface near the tip of the crack I could make the crack grow, and if I pushed off center, the crack would turn slightly towards the spot I was pushing against.
Just have the windshield replaced, that is the safest way to go.
I am a car dealer, and I have had dozens of windshields replaced.
Most of them only cost about $125 -$150, and I use Triumph auto glass here in Atlanta. They quote me a price, I ask for a lower price, and they always deduct $25-$50, and I don’t even have to tell them I am a dealer. IMHO, it is not worth to try to drill into a windshield or try to “guide” a crack.
BTW, many times windshield companies will ask if insurance is paying for the repair, and if you answer “yes”, the price is much higher.
If you can get a good clean small hole, it will work. But at a 12" crack if it’s anywhere near the driver, replace the glass. I’ve done the same thing bbeaty did guiding the crack through tapping and flexing the window.
Some windshields are 4 layers, glass - plastic - glass - plastic on the inside. The fourth layer is intended to protect the occupents from glass shards when their face slides up the glass in a wreck.
I’d just have it replaced though.
If you’ve got a dentist’s drill, you have a chance - if not, don’t waste your time. Plus, it may be illegal to drive if the crack interfers with the driver’s vision. How well do you get along with the local constables? 
I’d try drilling just for the hell of it.
Flanders: What’re you putting holes in your car for, Homer?
Homer (with pickaxe): Those are speedholes.
maybe i’ll try drilling when i get enough money for a new one.
beajerry, the trick is not to get a new one and not to fix the old one. Call around and get a USED one.
You will save a bundle and I challenge you to tell the difference between a brand new windshield and one that’s been stripped off a junker.
When I first learned about this option (I had to replace a side door window twice, thanks to lowlife crackheads) I thought I was in for some shady backroom operation. But I was wrong. There is an entire industry built around reselling used glass – maybe not in the swankiest part of town, but they’re pleasant and honest (at least the ones I’ve used). These guys even have computerized inventories so you can shop by phone to find who has the piece you need at what price.
Look in the yellow pages under “Auto Glass” and see whose ads mention used glass. Also look under things like junk yards/ salvage/ wrecking/ auto parts – that sort of thing.
Yes you can dril your windowsheild glass. If you have a dremmel or know someone with one, get the diamond or nickle-carbide bit and use a little vaseline whilst drilling and go slooooow.
**I am assuming you do not have insurance, or you do not have glass coverage on your insurance. If the latter, call your insurer up, put glass coverage on your policy - it’s like $37. extra a year - and then wait a couple days, and call them about your window. They’ll come out and replace it free.
Something no one has mentioned is that, in many states, driving a car with a cracked windshield is illegal. Driving one with an intentionally drilled hole in the windshield would be equally illegal. Generally, the law is worded something like, “cracks longer than <fill in the blank> inches…” I suspect a twelve inch crack would exceed any such limit.
Also, if you’re going to do it, anyway, there are special drill bits designed for drilling tempered glass, such as that used in windshields. Make sure you get one. Using the wrong bit is likely to result in shattering the top layer into thousands of little bits like the ones left behind at accident scenes.
**cough, Plus, it may be illegal to drive if the crack interfers with the driver’s vision., cough **
You don’t need to drill the crack to stop it. As others have stated, you will probably shatter the windshield first. All you need is a glass cutter, you can buy them at any home improvement store for a couple bucks. At the end of the crack, score a line about half an inch long 90 degrees to the crack. The scored line should be deep enough at the crack to catch a fingernail then taper to flush with the glass at the ends. This is how I stopped cracks on windshields in my stock car racing days and none of the cracks ever grew after I scored the end of the crack.
Great tip, racer!
NICE!!!
I’d follow racer’s suggestion.
I’ve heard of people drilling holes in indshield glass on custom cars (for the wipers), but they used a piece of tubing and valve lapping compound (a gritty paste) to grind a hole instead of trying to cut the hole with a drill.