Polo-94Z28

Is there anyway to remove the coating that comes on the Factory Lexan tops for these cars? Mines gone all gross looking. Its all cracking and flaking off. Ive tried buffing with with some abrasives and polishing it up, but now it just looks all cracked and shiney... grrrrrr not coming off when I want it to

Thanks

-Zach


1992 25th Z28 Hawaiian Orchid Power Everything

firebirdjosh

iTrader: (1)

Well my lexan t-tops cracked straight through and didn't have a coating on it. Are you sure its a coating that cracked?

Polo-94Z28

Oh yeah, its the coating, looks just like a clear coat on a car coming off, but whats still on is stuck nicely. I can scrape it off with a razor blade but it would take many many many (did I say many?) hours, and ends up taking little pieces of acrylic off as well. I think I'm just kind of stuck with em.... ah well.

-Zach

1tinindian

Wet sand them with 1500 grit, and buff out as you would on a paint job.

Did it on my brothers 91 'bird, and they looked like new, when finished.

I don't think that it's a coating coming of, rather it is the plastic delaminating, due to exposure to the sun and elements.

Good Luck,

Leon.

smokefan

does any one know what year they started putting the lexan tops on. i have a 86 iroc with glass tops and i got a set of lexan off of a 91 bird but they are all pealing. would they fit on the 86

firebirdjosh

iTrader: (1)

I put 85 glass camaro tops on my 89 lexan equipped firebird.

Polo-94Z28

I think Lexan tops came on 89 and later F-Bodys... but there are different latch styles and seal styles for different years. Early models have hook style, then theres 3/8" pin style, like 4th gens, and my Lexan tops have like 3/8" pin with a large plastic sleeve, almost 3/4"pin style. And then there are the seal changes, i know theres a post with the exact info here, just have to find it.

1tinindian, ill give what you suggested a try tonight, thanks much.


-Zach

okfoz

THe seal changed I belive in 1989,

The ACRYLIC tops were introduced in 1989 as well, and I belive were discontinued in 1991, (some 1991 produced 1992 F-cars may have acrylic tops).

The large pin retracts into the T-top on the Acrylic tops. The recievers I have are the same for Glass and plastic tops, but the adjustment is definately different as the Acrylic tops are adjusted lower than the glass tops. At least with the set of tops I have, they would work with any other "PIN" style factory T-top.

The small spider web cracks are called crazing, the tops were hard-coated and that too will begin to flake off. So you can actually have a miriad of things going on.

Crazing, although it appears to be on the surface at first, is usually just below the surface. With enough work you can remove the crazing through an agressive sanding, and then polishing. THe life of acrylic is deterined by what it is exposed to. Many chemicals will cause crazing, Initally the plastic will look hazy, and the it will begin to become more severe and then the small crazing cracks form. Crazing is a breakdown of the acrylic, and eventually it will cause a real crack. Since acrylic is notch-sensitive each one of those crazing marks is a place for a crack to start.

The Hard coating will have to be completely removed in order to have a nice looking part, otherwise you will see the change to where there is and is not hardcoat. Its kind of like sanding through clear coat on paint, you will see the change in color when you do so.

I have considered making replacement acrylic t-top panels, but I do not think there is the real demand for doing so at this time.

Good luck

John

Polo-94Z28

Dang man... 100% info on that one, thanks a bunch. I have both crazing and the hardcoat is detaching. I did go ahead and sand the hardcoat off so at least its even. Took a bit of sanding thats for sure. Do you have any reccomendations as far as what to use to buff/polish back to a nice shine? I used some 3M final stage paint buffer stuff... the actual name skips my mind right now. It works nice but you can still see many of the lines. Looks like a black paintjob thats been gone over one to many times with a towel and not waxed or buffed... if that makes sense.

Thanks for the info though!

-Zach

okfoz

Actually since some automotive paints are acrylic based, you can use almost any polishing system. I like the McGuires, or the 3M are both fine choices. I would recommend doing sanding stages, starting with a coarse sand paper and then working your way to a fine (2000 Grit) sandpaper. Making sure you actually remove the scratches from the previous paper. You could probably get away with 800 or 1000 and then polish, but the extra work would be worth it.

Keep in mind that when you sand with a fine sand paper on a rough surface you will smothe the big bumps more than take them off. So you have to work your way up in number/Down to the finest grit you have.

NOTE: WET SANDING IS A HUGE KEY. Make sure your surface is nice and wet, use a bucket of clean water to dip your paper in. and use a sprayer if its too warm to keep it wet.

Once you think you have a good sanding finish, then buff it. take your time and be patient.

When you buff, don't get the surface hot, you can use water again with the compounds to help keep it cool. If you melt the surface by being too agressive, then you have to start over.

Good luck

John

Polo-94Z28

Ahh thanks much, I actually went ahead and used some 3M rubbing compound after sanding with 1500... wet sanding of course. Then moved onto 3M polish, it looks so much better, prolly put in about 3-4hrs a panel, but like I said, real improvment.

Not exactly sure how you would melt the surface of the lexan though, gotta be pushin pretty hard in the same spot to do that! But I guess anythings possible LOL.

Thanks for your info and time, appreciate it alot.

-Zach

Chris Luongo

A little wet-sanding tip for you guys. My ex's father was a good body man and taught me a few things.

Get a 20-ounce soda botle, and pierce a hole in the cap. If you don't have something to pierce a hole with, use a drill, or maybe screw a drywall screw in there a little bit and remove it.

As you are wet sanding, you can hold the bottle upside-down in your other hand, and water will constantly dribble onto your work.

1tinindian

I just use a hand pump spray bottle, works great for keeping the work area flushed with fresh water

Leon.

Gunny Highway

iTrader: (1)

Give it another 10 years or so when these cars become classics, then you should have the demand.

okfoz

In reality, I make windows for Aviation, and in regards to the amount of individual parts I actually sell, I would sell enough of these tops, unfortunately because of the labor involved with making true quality reproductions most people would opt not to pay the amount I would require to just break even.

Keep in mind that there is more work involved than just the part, THere is the Molds, then there is tooling to cut them out, and then there is also a milled edge which I would have to make a special cutter. Also remember that I would be using an Aviation grade of Plastic, just because thats what I have in stock.

How many people would actually pay $180 EACH per top to have new Acrylic for their tops? THats $360 for a pair? I think most people will go to glass.

John

dr1

personally i dont care, but look around people are crazy, they will pay $360 for some tops, lure them in with weight savings, heh

Dizturbed One

i'd pay 400 bucks for some acrylic tops

i like them so much better than the glass, but mine look like crap

they're delaminating AND crazing all to hell, and the crazing is pretty bad so I don't think there's any saving it.

other camaro guys look at me funny when i grab a t-top with one hand, flip it around all quick and catch it, walk around to the other side, and do the same thing, then put them both in the back. i know that the 50% of them that dont realize they're lexan are thinking "jesus, that guy has some strong hands"

lol

neubauej

I would gladly pay up to $500 a pair to have high quality, factory look Acrylic tops. I am quite sure you could find a number of people that feel the same way... Just how many do you think you would have to sell to turn a profit?

okfoz

To make a profit It would depend on how much I charge per part...

Since we would only be making is the actual "Glass" Portion of the top, there needs to be some way to bond the parts together, AND to get everything apart without distorting and destroying what your toing to reuse... I have considered doing an Exchange type deal, where a customer would send me their tops, then I would swap out the glass with new glass then return the tops. The problem is not everyone is mechanically inclined to the point to where they could do this...

With all that said its all things that really boil down to why we have not done the project yet...

John