With all this talk about windows for chop tops I just have to ask,
Is it possible to just cut the stock door window in two places and sand the edge smooth.
I would assume that the bottom and the back of the glass would stay the same.
So dose glass shops have the technology to cut them
I am think of my next mod to be a chop top but I wont to get the windows problem soleved first.

has any one try to cut them ?

I want them glass and want them to go up and down.

I've never tried cutting them, but I believe they are cut the size they need to be, then heated up to a certain temperature to make them tempered, as well as making them form the curve they need. This would make them almost impossible to cut as they would probably shatter as soon as you made your first score across it.
Brad

I once talked to a glass shop about trying to polish some scratches out of my T-tops. They told me that even polishing would heat them up enough to shatter them. So I assume that cutting any kind of tempered auto glass would doing it even faster.

Chris

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Chris

3.4 TDC SWAP COMPLETED...this is going to be a fun car

This might work: http://www.secondchancegarage.com/public/149.cfm

quote Originally posted by jsshark1: has any one try to cut them ?

Didn't Midshipman Easy try cutting a side window and it shattered into a million pieces? The best option for chop top side glass is to get them made like F355 Spider or build the car around an existing set of glass like the firebird.

Most glass in cars is now tempered glass (with the exception of the windshield, which is usually laminated - look for AS1 printed on it.) Tempered glass has an outer "skin", which when pierced, stress relieves the glass, causing it to shatter. Cutting a piece of tempered glass will cause it to shatter.

That wasn't me .. that was f355Spider... he was able to grind the glass down to a certain point and then it shattered.

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http://www.beattoquarters.com
--- My Projects Page

Cutting/shattering is not the only issue. That is to say, reshaping two edges is not the only issue.

The window edges wind up outboard of the relocated door seals. There may be enough adjustment available within the window track mechanisms to dial this out, but either a lot of readjustment has to be made, or else new glass with a different radius musst be used.

David Breeze

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Pantera Rebody Kits

quote Originally posted by Midshipman Easy: That wasn't me .. that was f355Spider... he was able to grind the glass down to a certain point and then it shattered.

I knew it was one of you but I didn't feel like looking for the thread.

You did grind down a windshield though, but that's laminated glass and not tempered.

[This message has been edited by jscott1 (edited 03-15-2006).]

It was too long ago to remember if it was tempered or not, but years ago when we chopped tops on hot rods, glass company always cut down our glass. Last chop I did was on a 56 chevy and all the glass was cut down 3 or 4 inches. A couple of years ago the glass shop trimmed down a factory Lamborghini Diablo windshield for my Warlock kit because it was an inch too big to fit their cuttout. I watched them finish it out with what looked like a belt grinder that sprayed water on it. Again, I dont know whether it was tempered glass or not (2000 Diablo).

The glass in this article is SAFETY GLASS. It's not the same as the side windows which are tempered safety glass. Safety glass is really two sheets of glass held to one another by a layer of plastic in between, and they are not tempered, at least not to the same degree as the side windows.

The side glass is made to shatter in many thousands of small, regularly shaped pieces as opposed to shards of glass. The windshield isn't the same as it has the plastic bonded between the layers and that will hold the glass in place, that's why you can see windshields with a hole through them and the rest of the windshield in place if you through something like a steel rod or signpost through them. Not going to happen on a Fiero side, back, or sunroof glass.

John Stricker

quote Originally posted by avengador1: This might work: http://www.secondchancegarage.com/public/149.cfm

Well if anyone knows of a glass shop willing to cut down a windshield PM me with the information.

I called and emailed every glass shop I could think of and only one place was even willing to try. Midshipman Easy is willing to try one for me, too, but there is no gaurantee it will work. If I can't figure out how to get a windshield in my chop t-top it will never be finished.

measure a windshield from a convertible sunbird/cavalier. or maybe even a **cough, cough** lebaron. seems like they may be shorter and could fit the bill. it's worth a trip to the boneyard with a tape measure. or better yet, a cardboard template.

I dont see why most shops wont try to cut one down for you. I work in a glass shop and I've done everything from make new glass for choptops(The old street rods with flat laminated door glass) to cutting down windshields. If a customer comes in with their own windshield to be cut down the understanding is that I'm not responsible if it breaks. Almost every customer if fine with that because without trying thier not going to get what they need.

Also a few people mentioned sanding down windshields with a wet belt sander...... most of the time when I reshape a piece of glass I reach for the 3x21 belt sander without coolant and use it dry. As long as I keep the belt moving over the glass and dont sit with it gring on one spot too long it will never break the glass.
Reshaping/gringing tempered is a different story. It can be done..... but probaly only 20-30% of the time the glass doesnt break. When tempered glass is made it becomes very strong but its as if its under constant pressure. Grinding it down stresses out the glass even more then it already was and will cause it to blow up as youre working on it or at some unsuspected moment after completing the grinding.
If you need any tips or info on working with glass shoot me a PM and I'll be happy to help.
Hope this helped some.
Drew

Edit: after posting this I noticed that it was directed more twards jscott1 than the origional post. Sorry for the hyjacking

[This message has been edited by 88fierocoupe (edited 03-16-2006).]

no problem, but i still dont now what to do about getting windows before starting my chop

OPM2000, that was my next quetion, the radius of the glass,
I understand that it pushes out on the way up but I would be trying to cut the top and frond edge of the glass
so when closed the window would still be the same posision agensed the window seal but missing 1 1/2 from the top and
a off angle amount off the front,

pick and pull is having a 1/2 off this weekend and i was thinking of getting a door glass to try cutting.

has thier been any stock door glass out of another car that has been used that had the chop top made around it, and if so
what car did it come out of.

thanks

Windshields are laminated safety glass, so they CAN be cut down. Tempered glass, as used in your side windows cannot be cut. Laminated safety glass has an AS1 designation - you'll see that printed on your windshiled just below the shaded portion - while tempered glass has an AS2 designation. You can cut AS1 glass, but not AS2 glass.

quote Originally posted by 88fierocoupe: I dont see why most shops wont try to cut one down for you.

As I said, I thought it would be simple, but 99% of the glass shops I contacted didn't want any part of cutting down a windshield. All they want to do is order a windshield out of a catalog and put it in. Most shops today just want to do insurance work restoring a car to stock and don't want to deal with anything custom.

quote Originally posted by jsshark1: pick and pull is having a 1/2 off this weekend and i was thinking of getting a door glass to try cutting.

That's the thing to do. Get a window and find someone to cut it down for you. If that much is successful, then try installing it in an unchopped door, just to see if you can adjust it inward enough.

You can just roll your window down 3.5" or so right now and look at where the glass is. Drop a verticle line straight down from the drip rail, and you'll see how far inwards you will have to adjust the altered glass.

David Breeze

Well I am on a mission now; I want a chop top for my next mod. I have till the weather clears up to get glass that will work.
When the weather clears up it's time to ride my privet jet (96 SUZ GXSR 750) that will give me a chance to bring my fiero down and do my chop top.

I will get the glass this weekend from - Pick Your Part- ( sorry guys I told you pick and pull, pick your part is the one having the 1/2 off sale 17, 18, 19th) and see if I can get some one to cut them for me and if not I hope to get the glass cheep enough to just try to cut it my self, and if it brakes O well at least I tried , I have some ideas on how I am going to try to cut them but I am hopping to find some one I can just drop them off and get them back cut, we shall see

quote Originally posted by 88fierocoupe: Reshaping/gringing tempered is a different story. It can be done..... but probaly only 20-30% of the time the glass doesnt break. When tempered glass is made it becomes very strong but its as if its under constant pressure. Grinding it down stresses out the glass even more then it already was and will cause it to blow up as youre working on it or at some unsuspected moment after completing the grinding. If you need any tips or info on working with glass shoot me a PM and I'll be happy to help. Hope this helped some. Drew

So if someone was successful in grinding/cutting a side window, are you saying that from then on, it would have a tendency to break alot easier, as if the molecules were permanantly changed from being cut? Like if someone came up and tapped a little hard on the glass?

If it was more prone to breaking after a successful attempt to cut it, I don't think I would want it in my car.

I still will try with my spare set, but would like to know for sure.

You know guys, just a thought. My 300 hp 200+mph Bellanca Viking has plastic windows and windshield, and I never give it a second thought.

David Breeze

Their plexiglass and less susceptable to scratching than lexan. All aircraft windows I know of are plexiglass. I think most if not all the people here that made side windows made them out of lexan. Its less breakable, but easier to scratch up. Ive made race car windshields out of both over the years.

So you have a Viking? Isnt that the retractable one that locks gear down by just an overcenter cam held in place by just the weight of the plane? I had a friend with some Bellanca, and he was always having to have them bring down a big airbag to lift it up when one of the mains folded over turning on taxiways too fast.

[This message has been edited by rogergarrison (edited 03-18-2006).]

Many race cars are now using a product called MARGARD because it is so scratch resistant. My understanding is that it is NOT FORMABLE, though, due to the special coating, so I'm not sure what they do for curved windows.

John Stricker

quote Originally posted by opm2000: You know guys, just a thought. My 300 hp 200+mph Bellanca Viking has plastic windows and windshield, and I never give it a second thought. David Breeze

quote Originally posted by slickrick2000: So if someone was successful in grinding/cutting a side window, are you saying that from then on, it would have a tendency to break alot easier, as if the molecules were permanantly changed from being cut? Like if someone came up and tapped a little hard on the glass? If it was more prone to breaking after a successful attempt to cut it, I don't think I would want it in my car. I still will try with my spare set, but would like to know for sure.

Its a hard deal to explain but tempered glass has an "edge" around the whole perimiter that can be altered to a certain extent. I highly doubt that 3"s can be taken off but I have accomplished 3/8" on door glass. Just the other day one of my coworkers was out in the showroom cleaning a shower door and it exploded just because he "looked at it wrong". He probably tapped a corner or an edge on something but the point is that tempered has a mind of its own.

opm2000 had an idea that I'd never thought of before.....You can just roll your window down 3.5" or so right now and look at where the glass is. Drop a verticle line straight down from the drip rail, and you'll see how far inwards you will have to adjust the altered glass.

I like that idea......... couldnt you build a choptop around a "rolled down window" alter the tracks of course to lean them in more but it might work!?
Maybe my ramblings have sparked some other ideas.

quote Originally posted by 88fierocoupe: opm2000 had an idea that I'd never thought of before.....You can just roll your window down 3.5" or so right now and look at where the glass is. Drop a verticle line straight down from the drip rail, and you'll see how far inwards you will have to adjust the altered glass. I like that idea......... couldnt you build a choptop around a "rolled down window" alter the tracks of course to lean them in more but it might work!? Maybe my ramblings have sparked some other ideas.

The vertical string 3 inches down is a good first approximation but the roof doesn't just drop down vertically 3 inches. The roof itself becomes about 2 inches shorter and is shifted towards the back by the same amount. So even if the angle at the A pillar didn't change, (and it does) the window rolled down isn't going to line up with the roof anymore.

Also, once you compensate for the angle change at the A pillar youv'e got the wrong angle at the B pillar. There is no way to accurately be right on both pillars with the stock glass and a chopped top. If someone can prove otherwise I'd be interested to see how it would be done.

Edited to say, one way it might work with stock glass rolled down is if you did just drop the roof down three inches. The only way to do that is to have a custom windshield. Now you still have to cut glass, but cutting the laminated safety glass in the windshield at least is within the realm of possibilities. However, I've been wrestling with the idea of a custom windshield. It's something I would rather avoid. As I have only once in 20 years needed to replace side glass, but I have had to replace at least 4 windshields due to damage.

[This message has been edited by jscott1 (edited 03-19-2006).]

Just a thought, but could someone with a water jet cutter (probably with abrasive)
cut glass? There is a shop 10 mi from here that uses them to cut everything I know of.
Metal, rubber, wood, etc.
Since there'd be little pressure and no heat, it might work.

[Edit]:
Since I had a little time on my hands and have cheap phone svc,
I called a few shops and they said they could cut anything but tempered glass.
Tempered glass is finished to shape, then heated up to about 600*. Air jets cool the outer
layer quickly and then the inner layer is allowed to cool separately. This sets up
a whale of a pressure differential, up to 50 MPa (7200psi). The piece is then a stressed
body. Removal of a part changes the stress vectors in the glass and then shattering is
likely.
One shop said they had seen a window glass cut, but they can't promise anything.
Just thought it was interesting.
tg

[This message has been edited by TennT (edited 03-20-2006).]

well I got a right side window this weekend from pick your part, thought I was going to get a deal till they charged me 5 extra bucks for their 30 day exchange policy, then they gave me all sorts of sh.... about it when I told them "I did not want that, give me my 5 bucks back", ( to late they already had it in their hands) they told me they ask me if I wanted it and I said yes( never asked). I then told then "I will bring back the hundred of peaces this is probably going to become and you then can give me another one because the hundred little peaces of window wont fit my car".

They still have my 5 buck

I am not looking for a 3 " chop but just 1 1/2 " chop. I would think that if I was to bring the window down 11/2 and have the B pillar
Lined up and the top lined up alls I would have to worry about is cutting the front angle off of the glass. To match the new angle of the windshield,

Let us know how it turns out, but more likely than not you will have a hundred little pieces of side window glass.

This may be a stupid question but... Why can't a glass shop make them out of safety glass instead of tempered glass?

quote Originally posted by fierogt88: This may be a stupid question but... Why can't a glass shop make them out of safety glass instead of tempered glass?

I was thinking that also....

Make a template of your side window. and also cut a arc in a piece of plywood to match the side window arc, then bring that to the u-pull and find a windshield with an arc very close to the template. Trace the template in the area with the correct arc and cut.

[This message has been edited by cancerkazoo (edited 03-21-2006).]

quote Originally posted by opm2000: You know guys, just a thought. My 300 hp 200+mph Bellanca Viking has plastic windows and windshield, and I never give it a second thought. David Breeze

Mmmm...Bellanca Viking...fabric covered mahagony plywood wing...so much smoother and sexier than riveted aluminum.

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86 Fiero 2.5L, 5spd.
00 Ford Focus 2.0L 5spd
66 Chevrolet C10 250 cid, Powerglide

Off topic, but yep, it's the Caddilac of the sky.

http://members.aol.com/viking300a/FrameSet1.html

David Breeze

[This message has been edited by opm2000 (edited 03-21-2006).]