RUMCars Forum

General Category => RUMCar Mart => Topic started by: richard on September 05, 2012, 11:17:43 AM

Title: plastic windscreen manufacturer ?
Post by: richard on September 05, 2012, 11:17:43 AM
looking to have a batch , 6 - 10 , of screens made for 1949/50 Bond Minicars . i believe polycarbon is the product to use . does anyone have a u.k. contact please - thanks
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 05, 2012, 11:29:15 AM
see pic. and rear all about Lawrie Bond's first racer
Title: Re: plastic windscreen manufacturer ?
Post by: Bob Purton on September 05, 2012, 02:04:29 PM
Did all the mk A's have a plastic screen Richard or was there an option to have glass? Some French microcar of this period had plastic screens too, I couldnt live with driving looking through a haze of fine scratches that you will get in a very short time. Still, if you are restoring to original and they all hed this then plastic it must be! The Tourette was to have a plastic screen but the idea was droped before production started for the reasons above.
Cant you use a flat piece? There is not much of a curve to pull it around.
Title: Re: plastic windscreen manufacturer ?
Post by: super-se7en (Malc Dudley) on September 05, 2012, 03:33:09 PM
3mm thick polycarbonate will bend easily but 5mm will need some heat.
Polycarbonate is soft and will scratch easily while acrylic is much harder but will shatter.
The heinkel club had some rear windows made i think using vac forming but you would need a pattern.
3mm poly carb is the way to go for the cheapest option using 3mm to 3mm window rubber.Or am i wrong.
Title: Re: plastic windscreen manufacturer ?
Post by: AndrewG on September 05, 2012, 03:45:10 PM
You need to contact a decent plastics supplier to get some specialist advice.  These are fairly local companies so I suggest the Yellow Pages.  Decent ones will give you the advice you need and work with you to find a good solution - if not, walk away.  If you have an existing screen that can be used to help make a mould, then costs will come down.

Some early Minicars seem to have unframed tops to their screens while others have four-sided frames.  With the four-sided ones you might get away with flat plastic just forced into place, but not with the open-topped ones.

Ditto what Malc said about polycarbonate and acrylic, but you can buy polycarbonate with a scratch-resistant coating (at a King's ransom) - that's what the windscreen of large touring motorcycles use. 

But..... the big proviso is are you expecting to be able to use the wiper?  If so, I think almost any plastic screen isn't going to last.  If owners are happy to take great care - and presumably many will be driving mostly in dry weather - then a scratch-resistant-coated plastic should work well.  But it's never going to be 'glass clear'.
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 05, 2012, 04:03:05 PM
this is one of the earliest surviving Bonds,  number 196 of 25,500 , the 3rd oldest survivor . i decided that as i found , fairly early on ,an original unused red vinyl hood i would go for original spec. vinyl screen . he alternative glass screen necessitates making a different hood .r as i have the original early 122cc engine , rather than the 197cc most were upgraded to ,weight saving is a consideration also  .as originally built it will "utilise " a hand operated windscreen wiper . thanks for the help i have emailed two companies and just wondered if anyone had a contact themselves .
Title: Re: plastic windscreen manufacturer ?
Post by: Barry on September 05, 2012, 04:08:44 PM
Could you leave a thin polyester laminate on the screen that could be changed from time to time.
There are films available for UV protection on household windows, cars and also Helmet visors?
Title: Re: plastic windscreen manufacturer ?
Post by: Big Al on September 05, 2012, 05:07:24 PM
There is also a Teflon water repellent coating that can disperse rain if there is gravity or airflow over the screen. It is an after market purchase and can be re applied.

For the amount of use and in prevailing conditions I think original is the way to go as it is not a car you would choose to use in set bad conditions these days. Yet as a thing to own in correct condition a most satisfying vehicle with a foot into cyclecars.
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 05, 2012, 05:18:26 PM
said it before but ..... a " shopping " car made with 122cc, plastic screen,hand screen wiper ,balloon tyres and NO rear suspension , coil spring and Andre Hartford friction shocks at the front ,within months they were touring post-war Europe two up with luggage on appalling roads . only after a few more months were the slightly larger 197cc engine and glass screen offerred as an option . this should  be good enough for my occasional run  ;)
Title: Re: plastic windscreen manufacturer ?
Post by: Rusty Chrome (Malcolm Parker) on September 05, 2012, 08:17:18 PM
Polycarbonate (Lexan) is stronger and tougher, but acrylic (Perspex) is actually more scratch resistant. It will chip, but then so will your glass windscreen. It'll also yellow over time, but it isn't hugely expensive and they do use it for F1 visors and helicopter windscreens so it must have some merit. I know the original Mark A screen was described as perspex and I wonder if it was just a flat sheet held in tension by the combination of uprights and bottom channel?
Title: Re: plastic windscreen manufacturer ?
Post by: AndrewG on September 16, 2012, 07:04:06 PM
I'm reviving this thread as I've just had info from a plastics specialist (in Canada!) who reckons that Markrolon AR2 (that's a polycarbonate with an abrasion-resistant coating on both faces) is durable enough to use wipers on.

I've got no information about whether it can be heat moulded without harming the coating.

This is about the only UK link I found to it: http://www.sheffieldplastics.com/product_info.cfm?nav_id=3,1,1,1
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 16, 2012, 07:19:10 PM
thanks very much indeed. have a couple of enquiries live so will bear this in mind.
Title: Re: plastic windscreen manufacturer ?
Post by: Barry on September 16, 2012, 07:58:14 PM
Makrolon is a trade name used by Bayer.

I am involved with injection moulding so not very helpful with sheet but you could try getting in touch with bayer directly.

Makrolon grades:-

http://www.matweb.com/search/GetMatlsByTradename.aspx?navletter=M&tn=Makrolon%C2%AE
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 16, 2012, 08:04:15 PM
one factor that will play a part is the delightfully old fashioned low prices that Bond owners have been used to paying over the years . They dont like to pay too much - and i say that as a Bond owner myself  ;) The cars relatively are worth quite little , it would be different if obtaining parts for messeschmitts and the like  :)
Title: Re: plastic windscreen manufacturer ?
Post by: Barry on September 16, 2012, 09:09:55 PM
Sorry - I didn't mean buy from Bayer.  They couldn't possibly supply material.  They may be able to give advice on standard grades available and alternative stockists.
Title: Re: plastic windscreen manufacturer ?
Post by: richard on September 16, 2012, 09:24:04 PM
yes thanks got that will ask our contacts and see what they make of it . much appreciated