Ok so I got this T-Top with my car that seems to be made of some type of polycarbonate such as lexan or plexiglass. I am pretty sure it wasn't a factory option, but I havn't found anything on it about aftermarket vendors, to make things more confusing it looks way to nice to be a fabrication job. I got a new set of T-Tops that are both glass which are on my car now, I really want to know where this other one came from. It looks like every other t-top except for on the top it has two metal rails that seem to be for support. Anyone know where that t-top came from?

 

Some factory tops were glass, some were lexan.

 

if i'm not mistaken 90 or 91 started using lexan but because of warping or some other issue, GM started replacing them back to glass. not possitivel they talk about it in the history pages on the left side of the home page, look up 90 or 91...it was a late model thing...

 

Part of 89 was Lexan, and late 91 and 92 was lexan, iirc.

 

Awesome, thanks guys.

 

They're not Lexan, they're actually just acrylic.

 

Except mine actually have LEXAN printed on them in the rear outer corners on the outside of each one along with all that other writing. Take a closer look at some that are not faded and you will see...

Alex

 

Are you sure it doesn't say "LEXAMAR" ????

 

pretty sure my 91 has glass. not going to drop them to find out. lol!

 

Hmmm, you could be right, lol! It has been years since I've read them with care...

 

LEXIMAR is the company that made the tops for GM here in MI. They clearly state "Acrylic" on the underside of the top on a decal that indicates special instructions for the top.

Acrylic is most commonly known as "Plexiglas" which is a trade name of Arkema (back in the day it was Rohm & Haas). The name Acrylic is actually a shortened word from the longer Methalmetacralate (not entirely sure on the spelling.)

Polycarbonate is a very different material, it scratches much easier but is tougher than Acrylic. The weight is about the same but it has some resonance issues that tend to make it Ring. Plycarbonate or Polycarb is also Known as Tuffak (again Arkema or Rohm & Haas), most commonly known as Lexan which is a GE trade name.

The tops wer Hard coated which is a coating which was applied to reduce scratching, the problem with hard coating is it is only good for 7 or so years exposure to the weather, at which point it tends to flake off. regular Acrylics which I use every day will last longer but tend to scrathc easier.

Oh yeah, yes they were an option on some F-bodies especially cars which required some weight savings.

What else do you want to know?

John