Thread: Chopped top glass

Tweet

When someone choppes a top, how do you get custom glass for the windshield (curved glass)?

They cut what you have to size. you cannot sucessfully cut the tempered safty glass used in new cars tho, you can out of luck.

Originally posted by Bob Stone
When someone choppes a top, how do you get custom glass for the windshield (curved glass)?

It's custom made. In the case of curved glass, you'll need a pattern that takes the curve into account. Start with a cardboard pattern, and then transfer this to sheet aluminum. When you have the pattern made, you'll need to ship the pattern to a glass shop without it getting damaged in the process.

Once I get this aluminum pattern cut to size, how do I maintain the exact curve of the glass frame in the aluminum pattern?

Will most auto glass shops be able to make the glass or is there a special shop?

If you just need a stock glass shortened, u can get a new windshield cut. Although it might take more than 1 try. Old glass is hard to cut because UV makes it too brittle. For tempered glass u have to lay the glass down or get a glass foundry to make a new one.

An easy way to sidestep all the problems you will encounter is to not chop the top, but then, you knew I'd say that didn't you

I've seen a few jobs ( in magazines ) where the window is recessed, and some where the window is tilted.

yup, saw that coming Tech!!!! Lexan works good for a replacement, too.

Originally posted by Bob Stone
[B}Will most auto glass shops be able to make the glass or is there a special shop? [/B]

From my experence most glass shops will not be able to do this. From what i've seen all they want to do is windshield replacements in newer cars. There are specialty shops that can make custom glass. I am currentlly having new glass put into my 67 el camino and they are having to make the rear glass. Most glass shops i called told me that i was out of luck and that new glass could not be put into it. I found a shop here in Denver that could do it. From what they are telling my they cut the glass then it is tempered after. Luckly the rear is flat so it's not all that expensive, like $150.

no normal glass shops will not be avle to do this....you will need to go to a auto glass manufacturer.....up here in canada the company is called PPG. Another alternative is to buy 3mm Lexan. make your template to the rough size of the opening, a little bigger if possible, then cut the lexan to a sightly larger size, lay your old windsheild down on some saw horses....
lay the lexan on top and use a heat gun and start heating the lexan, when it warms it will conform to your glass and will shape itself. once the shape is formed, you will need to grind edges to make a nice fit, then when it fits use windsheild sealer and mount it, you can add a couple of screws into the glass and channel for added strength, the molding will hide it. this is the easiest route i feel. But having molded and custom cut glass might be expensive, try emailling boyd coddington, ive watched a couple of his shows and they use glass. might be an option......good luck hope this helps

Ok, keep the ideas coming. I appreciate all the input and I need lots of input. So far 2 are out. Techinspector1 is out because the top is already chopped(your right, I expected that answer nice try). Lexan is out also....not legal in Wisconsin.

In fact, that is what's in it now.

ok find the nearest glass manufacturer, one that does tempering, if they cant do it thry will guide you to someone who can hope this helps.

Price wise, Lexan is the cheapest route, other than cutting down a stock windshield. Lexan needs an oven at 300 degrees to take a shape.

I've seen suggestions for anealed glass cut, and then tempered. You can cut anealed, drill it, shave it, almost anything except bend it before tempering. After tempering, it can not be cut at all. It is also not used for windshields as it will not maintain a form in an accident, but will explode into little pieces.

Laminated glass is what is used in all windshields. A layer of vynl between two layers of glass. It takes some very specialized equipment to produce a bent glass windshield.

Try these guys.
http://www.procurveglass.com/index.html

Dean

Originally posted by Bob Stone
Once I get this aluminum pattern cut to size, how do I maintain the exact curve of the glass frame in the aluminum pattern?

Will most auto glass shops be able to make the glass or is there a special shop?

The pattern will need to be formed to the opening of the windshield. Some glass manufacturers can do custom work, but not all. You'll have to do some checking locally to see if you can find someone.

well you have to have a 3D pattern, they will digitize it and machine an unwarpable pattern from it.
you have to take the 2D pattern and weld/fiberglass a curve template to it, porbably in at least two places (upper and lower) perpendicular to that to hold your 3D curve
it's REAL expensive- mine was ~22X26" (tiny) and cost $2065

a more stock windshield you could just ship them a windshield and show them how short it has to be- lots easier, but they will have to machine a digitized (steel?) pattern, coz the glass has to be real hot I would guess, but no less expensive for them to do.

still, this is REAL expensive. a guy has the link in above post for a Hastboro PA shop I used

I wasn't happy with the way they did mine- they thought somehow it was supposed to be 1" shorter than my template showed, but I just added a windshield gasket and changed the pillar abit.

The only other alternative is find a shop that cuts glass and bring them ~8 stock windshields- maybe one will survive cutting. I think this the most used method. Or try it yourself. Respirator (DON't bbreathe in any silicon dust) and faceshield, diamond cutting wheel using water as coolant. Cut lightly top/bottom of glass. Maybe start with a couple vent windows from a junkyard to see how it goes. This must approximately be what a glass shop would do. Just milk a glass shop for additional info while checking them out/begging.

you can see even if Lezan is illegal, it's cheaper to do it in Lexan and pay lotsa tickets. I just needed it coz the state inspector has to see it BEFORE I get a (now) 2006 special built bonded title/license