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Lexan question

Posted: Mon Mar 11, 2013 6:40 am
by Bruce69Camaro
My coworker bought some 1/8" lexan and made his door windows for his Mustang.

He got everything mounted and came out the next day, to find spider web cracks around the holes that he drilled in the one window.

So he made another one, but this time, used a hot tip to make the holes and the same thing happened.

Anyone ever have this problem?

Re: Lexan question

Posted: Mon Mar 11, 2013 9:30 pm
by DOTracer
Don't go very tight with the screws. Typically that causes the panel to warp anyway.

You absolutely sure it was lexan he has? I once bought a piece from Home Depot and turns out it wasn't Lexan, but another form of clear plastic and it cracked very easily. Lexan you can shear and bend on a sheetmetal brake and it won't crack.

Re: Lexan question

Posted: Tue Mar 12, 2013 4:51 am
by Bruce69Camaro
It was a 4' x 8' sheet of 1/8" lexan from a local business that our company deals with and he said the same thing, he could bend it, twist it and it wouldn't break, but he drill's holes and it cracks.

He told me he gave up and put the glass back in.

Re: Lexan question

Posted: Tue Mar 12, 2013 6:18 am
by DOTracer
Well if it truly was lexan the only reason for it to star crack around the screws is either he tightened the screws way too tight, or it was a flat sheet and he was trying to force it to bend into a shape and using the screws to hold that curvature.

I myself don't care for using flat sheet in cars. it rarely looks correct and just makes the job look cheap when done.

Re: Lexan question

Posted: Tue Mar 12, 2013 7:49 am
by John_Heard
Sounds like he was using Plexiglass, not lexan.

Todd I used 1/8" flat sheet in my door and rear windows, I think it turned out real well and I don't think you would be able to tell it's not prebent. What I did learn is that marguard stuff really does make a big difference in scratch resistance.

Image

Re: Lexan question

Posted: Tue Mar 12, 2013 8:47 am
by Bruce69Camaro
John, that car of your's is so nice.

I wish I could actually see and hear it run sometime.

We actually have used polycarbonate or lexan here in the lab to make a combustion chamber wrapper for one of our heat exchangers and I had no issues drilling and screwing it to the boiler. He got this lexan from the same supplier that we have used before. Maybe there was something defective in the material??

I asked him how tight he made the bolts and he said they were hand tight.

He made his windshield and rear window out of lexan, he just didn't have luck with the side windows.

Who know's, it's another unsolved mystery......

Re: Lexan question

Posted: Tue Mar 12, 2013 9:34 am
by John_Heard
Thanks - I'll try and get some video this summer...

Lexan shouldn't crack like that, so something is weird with that material he had...

Re: Lexan question

Posted: Fri Mar 07, 2014 10:44 am
by supernova
Hey John,
I have glass doors from Glasstek and bought all the Tim McAmis hardware to mount and open and close the doors but I can't swallow the price for the windows.
What did you use for windows and where did you get it?

Re: Lexan question

Posted: Fri Mar 07, 2014 10:59 am
by John_Heard
I just bought a 4x8 3/16" thick sheet at Regal Plastics. I used that to make everything except the front window. $154 w/tax.

It is NOT scratch resistant, but I figured for $154 bucks compared to the Maurgaurd prices, I can afford to change it out often and still come out ahead. The Maurguard is better, just pretty expensive compared to regular lexan sheet.

They probably make scratch resistant sheets but probably double price? I didn't look into that at the time.

Re: Lexan question

Posted: Fri Mar 07, 2014 11:06 am
by supernova
Thank you for the info.
The 3/16 laid down and curved ok I guess? I'm only using it on the sides. The front and back glass was professionally installed so I'm leaving in for now.

Re: Lexan question

Posted: Fri Mar 07, 2014 11:48 am
by John_Heard
Yeah, the 3/16 isn't bad for curving really at all. I'm just using stock window felt in the channels. It's not super obvious the side windows are lexan.

Re: Lexan question

Posted: Wed Jan 20, 2016 6:41 am
by Bruce69Camaro
Bringing this thread back alive...

John, question about your windows.

Did you use 3/16" for the rear window or 1/8"? I saw you mentioned both sizes but wasn't sure what you used.

I see that you reinstalled the window trim, which I want to as well.

What butyl tape did you use and did you have to go with a thicker tape or was is standard?

Were you able to get away with just using the tape or did you have to put some screws in as well?

Re: Lexan question

Posted: Wed Jan 20, 2016 7:51 am
by John_Heard
I used 3/16, regular butyl tape and screws. Worked fine.
Bruce69Camaro wrote:Bringing this thread back alive...

John, question about your windows.

Did you use 3/16" for the rear window or 1/8"? I saw you mentioned both sizes but wasn't sure what you used.

I see that you reinstalled the window trim, which I want to as well.

What butyl tape did you use and did you have to go with a thicker tape or was is standard?

Were you able to get away with just using the tape or did you have to put some screws in as well?

Re: Lexan question

Posted: Wed Jan 20, 2016 9:09 am
by Bruce69Camaro
I believe Chris asked this, any issues with flexing?
I was going to wait till it was hot out, cut the pattern and tape it to the glass window and sit it in the sun to heat it up and form the shape.
How much wider all around did you make it or didn't you?
Thanks

Re: Lexan question

Posted: Wed Jan 20, 2016 9:47 am
by John_Heard
Yes, the 3/16 windows will flex some on the side and rear. I haven't noticed the front doing it very much though. I suppose that's because of the curvature of the front window.

I'm pretty sure I used the old window for a template, we cut it to rough size then clamped it to the old glass window around the outside and marked it. It might have ended up slightly larger, I know I wanted to have enough room to get the screw heads in there without them showing. Better to cut it big to start with then trim down if necessary.