Hi,

On my old car the centre section of the roof was originally heavy fabric (normal for the times, the reason is quite interesting but I digress). It currently has a GRP cover which is a longer lasting hot rod alternative to using the fabric, however I was thinking of replacing this with a thick plastic window, like a modern car full length glass roof which I think would be fabulous inside. This should be a very simple conversion with only the head lining needing trimmed back.

I'm not sure what the best plastic be to use would be, I'd like it if it was slightly tinted and shatter proof. I suppose I could get a film applied prior to fitting. But I'm thinking 8mm should be thick enough to stop sagging (there is a slight curvature of the roof which rules out using glass). I have found in the past, Acrylic is brittle and shatters in big spikey bits, Perspex is the only other name I know but I'm sure things have moved on in. So any ideas what material to use for this purpose?

Thanks

I think my 1st route would be to look for panoramic roofs used in some cars, see if you can find an OE glass panel that could be made to it.

First thoughts...

Having recently been in a van crash (upside down). Windscreen broke, but stayed together. Fornt windows shattered with galss fragments properly everywhere.


van-2

I'd imagine glass vehile rooves bonded to monocoque chassis have to be like windscreens for crash safety.

Maybe check out criteria with an MOT test station as a start point or perhaps Autoglass.

Polycarbonate sheet is shatterproof (used for riot shields).

Perspex is a tradename for acrylic sheet.

Thanks, like I said glass isn't an option due the roof being slightly curved, plus the weight of a sheet of glass that size would be quite excessive and harm the already questionable handling.

The original roof consists of rubberised fabric with wadding and then the headlining so it is not a structural part. I have seen one in Africa that had a full rag top conversion but I'm not keen on that as they often leak.

It never needs an MOT so I'm not bothered what is required by that and it's a body on frame so none of that applies.

do you want it to be transparent? or translucent? or even not pass the light through?

I would look at delivery van/ hi top. rooves, translucent grp, or compressed ABS Fibre.

this old trhead may give some pointers
https://www.locostbuilders.co.uk/viewthread.php?tid=161284

https://www.ebay.co.uk/itm/235335507249

This is used by the forestry guys who use it in forestry vehicles that get attached by trees . Margard. Lexan® Margard Polycarbonate |3mm|4mm|5mm|6mm

theplasticshop
https://www.theplasticshop.co.uk › lexan-margard-mr5e-...
Lexan® Margard MR5E sheet is a premium grade, hardcoated, high optical quality Lexan® polycarbonate sheet for building and vehicle safety & security glazing.

quote:

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Originally posted by Myke 2463
This is used by the forestry guys who use it in forestry vehicles that get attached by trees . Margard. Lexan® Margard Polycarbonate |3mm|4mm|5mm|6mm

theplasticshop
https://www.theplasticshop.co.uk › lexan-margard-mr5e-...
Lexan® Margard MR5E sheet is a premium grade, hardcoated, high optical quality Lexan® polycarbonate sheet for building and vehicle safety & security glazing.

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quote:

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Originally posted by jacko

quote:

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Originally posted by Myke 2463
This is used by the forestry guys who use it in forestry vehicles that get attached by trees . Margard. Lexan® Margard Polycarbonate |3mm|4mm|5mm|6mm

When iWorked in a vehicle body shop building riot vans for the police we fitted Margard on all the vans windows also on prison van cells windows
The only thing is it does scratch the good thing is you can get it tinted
Graham

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Interesting to hear. When I broke a house window a few years back (stone from the mower), the glazier did repair work at the local prison (HMP Winchester). Mainly replacing the little viewing glass on cell doors. often up to an inch thick and very toughened, but the inmates would find ways of breaking it

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Mr Whippy - 3/9/24 at 07:55 AM

quote:

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Originally posted by nick205

Interesting to hear. When I broke a house window a few years back (stone from the mower), the glazier did repair work at the local prison (HMP Winchester). Mainly replacing the little viewing glass on cell doors. often up to an inch thick and very toughened, but the inmates would find ways of breaking it

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Wow

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Mr Whippy - 3/9/24 at 08:12 AM

Great suggestions thanks. The Lexan® Margard Polycarbonate stuff sounds ideal, I haven't heard of that before.

Yes I'd like it to be transparent rather than just translucent (a light tint would be nice although @ 6mm it lets through 90% of light), it seems a shame to have a window in the roof and not be able to see through it.

As for using a panoramic roof from a production car, I had looked at this option but they are all really heavy and would need an additional frame and insert to make it fit the original hole in the roof and the car is already hopeless at going round corners! So adding all that additional weight high up would be very noticeable in a bad way. A plastic sheet should be much the same weight as the current GRP cover.

The car is about to come off the road for the winter at the end of the month and I will remove the current cover and see how to go about it.

Thanks

[Edited on 3/9/24 by Mr Whippy]

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ianhurley20 - 3/9/24 at 09:21 PM

quote:

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Originally posted by Rod Ends
Polycarbonate sheet is shatterproof (used for riot shields).

Perspex is a tradename for acrylic sheet.

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The actual name for the riot shields was Macralon. It was used on both shields and on the van windows (tinted black) and I can confirm that it will resist a shotgun blast at short range. Should be ok for a car roof maybe????

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Mr Whippy - 3/9/24 at 09:31 PM

Hopefully it will fair better than the Cybertrucks "bullet proof" windows, or anything for that matter...

I looked up the price of a Margard Polycarbonate panel, over £700

Normal polycarbonate is about £180, so that's what I'll be going for , considering the original is meant to be fabric I can live with that

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