Thread: How to drill rear windshield glass

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Hello,
My name is Steve and need some help. I need to drill a 1/2 inch hole in my rear windshield glass. I am doing a coustom rear wiper. The car is 1999 Subaru Impreza 2.5 RS . Not the normal car to talk about here but I have had no luck with the kids on my Subaru fourms. Any help would be great.

Cheers,
Steve

It would be cheaper to have a glass installer drill the hole than it would be to buy the equipment necessary. And, I'm betting there's no guarantee against glass breakage.

i have looked there and that is for glass bottles and such

As the owner of a high production (16 cars the first week I was open, 21 the second and 10 now on the lot for the start of week #3) body shop, I'll tell you right off that you need to find a competent custom glass shop to drill the hole for you. Forget about doing it yourself unless of course you have several spare rear hatch glass panels to play with first......


Bill S.

Thanks for the input. I have 2 rear glasses to play with and I was considering buying a plastic kiddie pool to submerge the glass. Now should I just use a regular drill with diamond glass bits? Also should i cut both sides to the plastic then use a razor knife to cut the plastic or should i just drill all the way through?

Steve

Looks like no glass guys here. Why not visit a glass shop and see if they might give u some more input?3dSMILE:

I use a carbide spade drill bit from McMaster Carr. I have drilling several glass boxes for craft work for my wife.

As far as automotive glass you can't drill tempered glass.... it is drilled before it is tempered.... you could drill safety glass ( "lamanted" 2 pieces of glass with plastic in the middle) like the windshield is made of. but in todays cars the rest of the glass is tempered. when you try to drill it it will break into little squares. Old Castle glass in LA Ca. could make you one but for $$$

Good Luck
MM64

yea, rear glass is always AS1 spec which is tempered, AS2 laminated saftey glass is windshield glass. you can check the glass label/ tag on it, on the bottom
sometimes in the middle, sometimes on the side it will say AS1 or AS2, auto manufactures have been doing this ( stamping glass information on window ) w/ window glass since as far back as 1951 that I know of, because my 1951 Chevy has every window stamped w/ glass information, and it's factory

seems to me a grinding stone at low RPM, + the kiddie pool will give you the results you want. Give it lots of time, and very little pressure and it should do fine.

a simple chip on the edge can shatter tempered glass. you can neither cut nor drill it.

Originally Posted by firebird77clone

seems to me a grinding stone at low RPM, + the kiddie pool will give you the results you want. Give it lots of time, and very little pressure and it should do fine.

If you try that, make sure you have a third glass available . . . to take to the glass shop after you break the first two.

The surface on tempered glass is harder than the core and is in a state of tension. Like a balloon if you cut a hole in it, it will "pop". Even if you successfully grind a hole through tempered glass it wont last long before it pops. You cant even trim tempered glass for this reason, the tempered surface is continuous on all edges and surfaces. Custom glass is the solution unless you can move the wiper into a nearby body panel instead.

scotter is 100% right on the money. i once tried to just smooth the edge down some. got away with it....almost. few min latter it exploded with no one close.

Don't think you will get a hole in the tempered glass.
We had a side window out of the suburban and smacked it with a wood baseball bat. Nothing. I got out a carbide drill bit and made the smallest scratch possible. Nothing....for about 10 minutes then it just started popping and completely crazed. We gave it a little tap and it was just a pile of tiny glass particles.

Once you break the surface tension it's gonner.