Lexan, Makrolon etc. windscreens - any good?

[Omerta]

I'm thinking about getting a Lexan (or Makrolon, or...) copy of a windscreen made to fit into a race car (TVR Cerbera which has a compound curved screen). Do they inevitably get scratched and cloudy over time, or are there materials or treatments available that are resistant to that now?

[Scuffers]

they are never going to match glass for wear etc, but Makrolon is about as good as it get's.

that said, making one for a multi-curve screen is not trivial, not sure who to point you at.

[FWDRacer]

Try this fella...

www.plastics4performance.co.uk

Paul loves a challenge!

[Omerta]

Ok cheers for that. I'm in New Zealand so no referrals needed

[wildman0609]

you will have to use lots of RainX when its wet as the wipers will scratch the screen.

[Chassis 33]

We're running hardened Lexan on Chimaera and Griff screens in DTEC with no trouble at present, so a Cerbera shouldn't be too different.

Regards
Iain

[Scuffers]

wildman0609 said:

you will have to use lots of RainX when its wet as the wipers will scratch the screen.

proper coated Makrolon will withstand the wipers, yes in time (like 2-3 years use) the marks will show, but they are not at all bad, perspex is another matter....

[Omerta]

Chassis 33 said:

We're running hardened Lexan on Chimaera and Griff screens in DTEC with no trouble at present, so a Cerbera shouldn't be too different.

How were they moulded? Droop formed using a glass screen as a former? I've been wondering if this is the best way but you obviously get a screen that's slightly bigger or smaller than the original (depending on whether you droop it on the inside or outside).

[Chassis 33]

We just use the legislated 4mm polycarbonate in flat sheet, start from the centre and work outwards. Drop Mike Saunders a line http://pistonheads.com/gassing/profile.asp?memberI... he's got a Cerb racer which I believe has a 6mm polycarb screen.

Regards
Iain
PS Do you know the chaps with the Chimaera racers, wouldn't mind exchanging a few notes at some point.

[With these feet]

We have run a P4P's 6mm polycarb screen for a season and a half.
They are sent off and coated so they have an incredibly tough outer layer.
We had previously gone through 2 regular laminated screens due to chips turning into cracks.

The poly screen has several big chips out of it from various offs, gravel rash and debris, even a glass screen will get damage from a lump of grit-filled pick-up hitting it, the poly still doesnt need replacing.

We were so impressed with it we have just fitted another to the new car.
Only slight downside is they are not quite as good optically as glass with a tiny bit of distortion.
This though may be different depending on the curvature of your screen.

Without a doubt, a polycarb screen is the way to go.

[Omerta]

Chassis 33 said:

Drop Mike Saunders a line

I will do that - shame how things have gone for him in the GT Cup, his skill and that car are a potent force (I've watched the races on youtube).

Chassis 33 said:

PS Do you know the chaps with the Chimaera racers, wouldn't mind exchanging a few notes at some point.

That was two guys who owned manufacturing businesses next door to each other in Auckland - Paul and Steve. Both were working on cars, one was finished the other not and as far as I know is still in parts - so there is only one car. The one that was finished with a big wing was yellow but now I think is black, and was sold a couple of years back - I don't know who to.

I don't have any contacts for Steve but you should be able to get in touch with Paul via PH mail - his profile is v8sag. He might know where the finished one has gone, and certainly knows a lot about the build. Let me know if you draw a blank and I can try to track them down another way.

[Omerta]

Correction - the other guy's name is Peter not Steve - here's some pics from 2008:
http://www.groundsky.co.nz/index.php?Action=VEN&am...

[teamHOLDENracing]

The Cerb screen is similar to the Sagaris - its not a compound curve and a screen can be made from a flat sheet. It does need to be bolted in though, and its under quite a bit of tension at either end. I use Lexan Marguard which has a scratch resistant coating and whilst it is not as good as glass, isn't bad.

[deviant]

Make sure you read your rule book first! The class my car is in has to have a factory windscreen.

[Omerta]

teamHOLDENracing said:

The Cerb screen is similar to the Sagaris - its not a compound curve and a screen can be made from a flat sheet. It does need to be bolted in though, and its under quite a bit of tension at either end. I use Lexan Marguard which has a scratch resistant coating and whilst it is not as good as glass, isn't bad.

Thanks Andy - I'll have to have a closer look at the one I've got hanging off the roof of my garage (earthquake resistant storage system ). ASs for class rules, what would be really useful would be some way of switching over glass and a Lexan ones without it being a huge effort as I'd like this thing to be road legal as well.

[Chassis 33]

Swapping between the two might pose difficulties as the OEM screen is bonded, I'm sure there's ways round it bit it will need no small amount of ingenuity.

I use #8 anchor nuts eg http://www.lasaero.com/site/products/article?id=Y1... and appropriate countersunk fasteners to hold my screen in approx 6" centres towards the middle of the screen and 3" at the outside edge and towards the outside of the top and bottom edges. The idea was stolen from Andy's Sag.
Regards
Iain

[teamHOLDENracing]

I use floating anchor nuts. Takes the pain out of drilling the holes in the screen in exactly the right place!

[Chassis 33]

teamHOLDENracing said:

I use floating anchor nuts. Takes the pain out of drilling the holes in the screen in exactly the right place!

Don't have the budget for floating nuts
Regards
Iain