My friend came by today and she made Plexiglas T-tops for her Camaro and I started to kick around the idea of making a plexiglas rear window. It would be a great weight reduction any thoughts?

 

www.onlinemetals.com

they sell it, not bad prices for the size needed.

1/4" MINIMUM thickness.

Take flat plexi, lay over glass, and heat with heat gun. cut off excess, wha-la...

EDIT: Weight will be around 15-20 Lbs... not the 80 plus stock glass...

EDIT2: Might want to call summit as well, they might have a racing application replacement window. But expect to pay 150-150+

 

Lowes or almost any "home improvement" type store will carry Plexi, but its ussually under a different name.

Some call it Lucite, some call it Acrylic, it doesnt really matter what its called.

Just ask someone where they keep thier Plexiglass and they will show you, they have plenty of sizes and can also cut it for you with thier special machine thing. (if you cut plexi with a jigsaw or something it will chip and stuff if you are not carefull)

 

You read my mind.

 

"She"?? Wow; got her phone number? That's cool.

 

Arnt you married, Tom???


I would like to se pic of the T-tops. Are they stock looking or hooptie???

I did a hooptie moon roof on an $200 chevette I had. I was so hot driving the sucker, I chopped a big hole in the roof and just covered it with plexie glass when it rained.

Matt

 

(laughs) Actually, I'm un-enaged as of 6/30/2003. I layed down an ultimatum that didn't work out in my favor-- or so I thought at the time, because what's weird is, I feel much happier lately.... even my friends have noticed. Less stress to deal with, I guess. Glad this happened before we got married!

But we're getting way off topic...

You could always put on a reproduction notchback hatch... those things are damn cool looking! Search the appearance board, you'll find a few pictures of them.

 

i guess you got lucky Tom. The only thing worse than being enaged is being married.

Matt

 

Hey now- I have been married for twelve years- and I must say- its been TWO of the happiest years of my life- A week here, a week there.

 

I'm going out with her anyway I got the glass off and no Tom I think notchbacks suck and take away the sporty look.

Matt, her T-tops don't look "hooptie" I thought they wer stock.

 

Oh and the glass weights 50lbs.

 

That's when you're supposed to say girlfriend instead of friend

Which glass? The t-tops or the hatch?

 

Hey I didn't say she was my gf yet! We had our first date on Friday she saw the shot gun and wanted to shoot it so we went to the shooting range followed by dinner lol her first time shooting it the gun just flew out of her arms. The glass off the hatch weights 50lbs. any good ways to heat it? I tried the torch and it gave the Plexiglas tiny little bubbles.

 

You needa heat gun, which is just a suped up hair dryer.
But using a torch msy be real tricky as you only want the heat hitting the plastic, notthe flame.

Matt

 

could you use a hair dryer

 

F585, How were these plexiglass t-tops made? I would be interested in doing the same. Thank you.

 

wonder if a thin sheet of aluminum could be formed in that shape and lose some weight. It would be then paintable and you do not need a back window if you have two mirrors. N like you can see out of it anyways.

Matt

 

or just leave them polished aluminum, might look trick.

NOTE: just woke up and had a dream(the dream was before i woke up) where i lost control of my fire bird at night on a wet road and slid off into dirt, crashed into a big wall, destroyed my beatifull car, it was sad. anyway, back to topic at hand.

 

i had a dream

i had a dream that all cars were equal.

then i woke up from the nightmare.....

imagine, soccer moms with high hp cars, or us with civic power....


anyhoo, you could make a back window.... but i would think that the way they are suggesting it would make a window that is exactly the thickness of the plexiglass bigger then stock..


oh, and put it in her butt.

 

The Acrylic T-tops were made by Leximar from casting a special grade of acrylic that would have a minimum amout of expansion and contraction with heat. Once cast the front and rear edges were milled.

Standard Plexiglas or Acrylic would work, but it does change a little with temperature, with expansion and contraction.

Using an Acrylic rear window will be great for losing some weight, it would probably weigh about 20-25# for the glass itself in 3/16" thick material. the down side is that Acrylic is no where near as stiff as Glass, so you would have some air leakage when you would be driving. With factory Acrylic t-tops you will notice a stiffening edge that is used to reduce flexing.

some things to keep in mind.

(Just as a side note, I make windshields for aircraft, I know quite a bit about acrylic, so ask away)

John

 

Not sure how she made'em and I don't want to ask it's bad enough she has the faster car but I plan on doing the T-tops too so I'll post how to do it wen I'm done.

 

Acrylic t-tops were an option...

John

 

Thank you, F585. I look forward to reading it.

okfoz, my car has a set of Lexan t-tops but one is cracked. When I went looking around for a replacement to junkyards, etc, I also checked out glass manufacturers and stuff. No one would touch the idea of making me a t-top out of plexiglass.

Cracked plexiglass can't be repaired, can it?

 

It can be repaired, but it might not be perfect, you might have to re-inforce it with something like an extra layer of acrylic.

I have considered making replacement tops for show purposes only...

John

 

"Might not be perfect" is a whole lot better than the huge crack that runs horizontally through it. Perhaps one of these days I will try to repair it. I would really like to.

 

I think I would use lexan rather than plexiglass, plexi will shatter and leave sharp edges, the lexan just bends and is very hard to break.
So she likes cars AND firearms? ,does she have a sister?

 

I had no problem busting a Lexan.

 

you'll have less problem busting plexi.

 

john about thoes aircraft windows...

some appeared to be bolted/riveted in... doesnt it get overstressed where the holes are?

or is it bonded and the lip is just rivited near it?

 

Many aircraft windshields are drilled and screwed or riveted in, and yes and no about the holes being a starting point of cracks. A properly drilled hole is very strong, matter of fact they use what is called a stop drill to stop a crack from spreading in plexiglas.

The problem with Plexiglas is it is notch sensitive, so where there is a small crack or a notch plex has a tendancy to crack from that point. When most people drill a hole and the hole is improperly drilled is when cracks happen.

If you look really close at the hole and there are chips on the exit side of the hole then these need to be cleaned up with either a slightly larger hole or a countersink. Matter of fact a slight coutersink on all holes in plexiglas is not a bad idea...

Most of the newer aircraft manufactureres use a channel that keeps the windshield from popping out, Cessnas use a clip at the top that keeps the windshield in, Beechcraft uses a seperate frame that sandwiches the acrylic and the frame is then installed into the aircraft, Cirrus Design bonds the windshield in.

I hope that helps.

John

 

I would agree completely with okfoz, When we first started using lexan on the stock cars we riveted them in, then they started cracking in that area. Later, we started screwing them in with button head allen screws and self locking nuts, this way we could keep the nuts tight without placing undue stress on the lexan, That solved a lot of problems for us. Although I would expect the aircraft industry to have some trick way around mounting lexan.

 

Trick way??? thats cute, actually they have problems like everyone esle... not to mention We use Acrylic for most general aviation... there are few exceptions of aircraft using lexan.

The best thing to do is to use lock nuts and not over tighten, a little rubber bushing so screws do not have direct contact with the window is also helpful

John

 

Not to steal the board...but
Has anyone ever tried to make a solid t-top. Mine are tinted and it still gets hot on sunny days with the air on. A car color t-top would look cool on sunny days and if you made it out of something light it would save weight.
Just a thought
Jared

 

I made some t-top shades that I painted silver on the top side, it reflects ALOT of heat, and the car is not nearly as hot as it used to be.

John

 

thanks
but i was wondering
I'm getting ready to do a motor swap and while i don't have the motor yet i know it will be stronger than the 180 hp 305 that's coming out. Would a t-top that was stonger reduce flex when i was racing. For instance if i made a set to put on only when i was racing would it help the t-top flex? I'm dropping a lot of money on engines and i don't think i'll have money for sub-frame connectors yet. Just wondering

 

Dude, words of wisdom, strengthen the car before you do major engine mods... It will be MORE expensive later if you twist the car badly, spend $200 for the SFC's and be done with it... peace of mind, is why I did mine... And is why I will be puting SFC's on my somewhat unusual original 87 Formula 5 Speed TPI-T-top car...



John

 

How hard are they to install? I.E. a few tools in a garage or a few shops with garages
I'm new to cars and don't have a whole lot of skill yet.
thanks
jared

 

I guess it depends on what your talents are... SFC's are pretty straight forward, You can take them to most mechanics and have them installed. (peal back the carpet first) Its easier on a lift. Even places that do exhaust should be able to do it.

When having them installed Your best bet is to put them on some sort of lift that would pick the car up by the wheels (or at lest the suspension) and put them on. When they lift a car by frame points it might flex the car and once installed it would be permanently flexed to some degree.

There are different manufacturers of SFC's I got the SSM ones and they were ok, I had to powdercoat them becasue they were bare Steel when I got them.

I hear good things about Spohn, but know nothing about them.

good luck

John