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Perspex/acrylic rear hard top window replacement.

Posted: Thu Jul 24, 2014 9:17 am
by Sage
Anyone ever done this or researched it? Any local places to purchase.

Saw this - looks like a good weight reduction as well as some additional functionality.

http://forum.miata.net/vb/showthread.php?t=477975

thoughts?

Re: Perspex/acrylic rear hard top window replacement.

Posted: Thu Jul 24, 2014 11:37 am
by 93_Clubman
Lightyear's various hardtop posts contain a bit of info.

Re: Perspex/acrylic rear hard top window replacement.

Posted: Thu Jul 24, 2014 2:28 pm
by Magpie
Is the car to be used on the road? If so then, at least for Queensland consider

Transparent material (e.g. glass, acrylic) used in a windscreen, window or interior partition of a motor vehicle manufactured after June 1953 must have the characteristics required by any of the following standards:
• Australian and New Zealand Standard S/NZS 2080 Safety Glass for Land Vehicles
• British Standard BS AU178: Road Vehicle Safety Glass
• Japanese Industrial Standard JIS R 3211 Safety Glazing Materials for Road Vehicles
• American National Standard ANSI Z26.1 Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highway
• United Nations Economic Commission for Europe (UNECE) Regulation 43/00 Uniform Provisions Concerning Approval of Safety Glazing and Glazing Materials
• New Zealand Standard (NZS) 5443

Also be aware that depending on what competition you want to compete in, non OEM glass can bump you up a group, for example in Queensland Time Attack non OEM glass bumps you to outright.

CAMS Schedule A states:
10. have any window or windscreen fitted made from a material which is clear or, if tinted, compliant with AS 2080

Re: Perspex/acrylic rear hard top window replacement.

Posted: Thu Jul 24, 2014 5:20 pm
by Mr Morlock
The mounting in the article to me looks really agricultural at least for the road.

I am not sure if their choice of material is qute right. Acrylic does not have particularly good impact resistance - tail light lenses and many optical items are acrylic. Headlamp lenses are PC and have great impact strength but poor UV resistance- acrylic is very good for UV. PC has to be hard coated to have good UV resistance and thats what the OEMS do.

Insofar as specs are concerned if there is a ready made rear window the maker should be able to state what spec it meets ( they may only have the spec for the material itself not the final product- there is no chance at all any privateer will be able to test a product .

If someone wanted to do this for their car starting from scratch I reckon it would be very difficult.

Re: Perspex/acrylic rear hard top window replacement.

Posted: Thu Jul 24, 2014 6:05 pm
by 93_Clubman
Mr Morlock wrote:I am not sure if their choice of material is qute right. Acrylic does not have particularly good impact resistance...

Which is why Lightyear recommends & used polycarbonate:
search.php?keywords=polycarbonate&terms=all&author=lightyear&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

Re: Perspex/acrylic rear hard top window replacement.

Posted: Sat Jul 26, 2014 4:18 pm
by Sage
thanks guys. all good comments. going to look into it a bit more.