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Polycarbonate thermoforming

Posted: Mon Sep 19, 11 6:34 pm
by Jon Connolly
Anyone know anyone that can thermoform large polycarbonate sheets to form windscreen / rear hatch / side windows

Here in UK ????


Also want the borders screen printed black

Anyone ? I seem to remember there is a UK dragster carrying the name of a sponser who does it but can`t remember their name ??

TIA

Posted: Mon Sep 19, 11 7:30 pm
by 74challenger318
Jon,

Used these in bolton for race car stuff, only thing is they may have to make a mould , do you have old glass, if so you need some fiberglass moulds making

http://www.plastics4performance.com/default.asp?

Paul :thumbright:

Posted: Mon Sep 19, 11 8:33 pm
by mopar_mark
Jon,
I personally feel you do not need to thermoform the polycarbonate for your car . . . . that is, unless you intend to use things like regular window mechanisms for side windows.

As it's a full out race car, why not use frame & tabs to mount side windows. Polycarbonate will flex pull into shape.

Front screen curvature should not be an issue either, I just used regular flat polycarbonate on the Cuda.

As for the black paint, I forget the name of it, but you have to use the same paint as used by modelers for kit cars. Same stuff you painted inside clear bodies on scalectrics, if you remember or played with them as a kid :D

Posted: Mon Sep 19, 11 8:53 pm
by Jon Connolly
Paul .. thanks.

You naughty boy with that avatar



Mark .. I only used flat sheet before but didn`t have great results, didn`t bend very well and is brittle 2 - 3 years later. Maybe I need to use thicker. Do you remember what thickness you used ?


TIA

Scalextric : course I remember, had a grand prix figure 8 when I was 9

Posted: Mon Sep 19, 11 9:30 pm
by TyreFryer
Would that be enamel Mark, like the old Humbrol paint. All the modelling paint nowadays seems to be acrylic.

I was intending to use flat sheets of Lexan and would also be interested in the thickness used. Also how did you both attach it and did you use any insulating material/gasket?

Posted: Mon Sep 19, 11 9:50 pm
by 74challenger318
this is the black primer


http://www.ebay.co.uk/itm/WINDSCREEN-BO ... 5639fde6fb


i use these to put it on

http://www.ebay.co.uk/itm/FELT-SWABS-AP ... 1c17e5d116


if you have a steady hand you can follow edge of window round, i usually drill and countersink window and secure with m4 countersunk capheads to the original window recess/lip.

Posted: Mon Sep 19, 11 10:44 pm
by Jon Connolly
Thanks for that Paul

Handy :thumbright:

Posted: Mon Sep 19, 11 11:59 pm
by mopar_mark
Jon Connolly wrote:Paul .. thanks.

You naughty boy with that avatar



Mark .. I only used flat sheet before but didn`t have great results, didn`t bend very well and is brittle 2 - 3 years later. Maybe I need to use thicker. Do you remember what thickness you used ?


TIA

Scalextric : course I remember, had a grand prix figure 8 when I was 9
Polycarbonate should not be brittle, I used Marguard the last time, as was meant to add more scratch resistance, protection. But any good brand such as Lexan, etc.
If its proper polycarbonate you can bend it to 90 Degrees or more with slight bit of heat /warmth to help it stays were it should be

I used 4 mm thick for front & rear screens & 5mm thick for the side windows.

What I did do & was a Bananarama! job, was to cut out the old windscreen supports & make new supports for the Polycarbonate screen. Then got my mate to welded in new supports, so that I ended with new screens flush to body.
A lot of work, but makes the difference when looking at the car, downside being if you wanted to revert back.

I used stainless button heads to secure (think 4mm ? but cars not here to check) to secure to frames or wind screen surrounds.

After the screen surround, the next longest job was marking out screw holes to get them equally spaced, no big drama, just a lot of measuring & marking.

I didn't use any sealer or rubber to seal, if its really pooring/hammering down water will seap by.

New screens were masked & painted black, if you don't use the right paint it will just peel off, ask me how I know :D

Oh yeah, the side window frames - I bought the window tabs, as was too many to make & was not much to buy tabs & saved considerable time.

Think I got them through chassis engineering, not sure what they were advertised as ? Also had a nice slot in them, kind of like a lightening/weight reducing slot

Cheers

Posted: Tue Sep 20, 11 12:02 am
by mopar_mark
TyreFryer wrote:Would that be enamel Mark, like the old Humbrol paint. All the modelling paint nowadays seems to be acrylic.

I was intending to use flat sheets of Lexan and would also be interested in the thickness used. Also how did you both attach it and did you use any insulating material/gasket?
I think it was enamel, will see if I have any left in the garage, bear with me though, as I have 3/4 packed garage in preparation for the move.

edit: Heres the stuff http://www.anticsonline.co.uk/1321_1.html


edit: window pics

Image

Image

Heres picture of the tabs, I also used them when I was making parachute mount Image

Posted: Tue Sep 20, 11 12:17 am
by TyreFryer
Excellent, cheers Mark.

I found this place that supplies countersunk and button head stainless screws: http://www.modelfixings.co.uk/stainless ... rsunks.htm

Paul, I remember the guy who refitted the back screen on my Challenger using that black dye and swabs. He just wiped around it using the edge and his finger as a guide, very neat.

Posted: Tue Sep 20, 11 12:21 am
by mopar_mark
TyreFryer wrote:Excellent, cheers Mark.

I found this place that supplies countersunk and button head stainless screws: http://www.modelfixings.co.uk/stainless ... rsunks.htm

Paul, I remember the guy who refitted the back screen on my Challenger using that black dye and swabs. He just wiped around it using the edge and his finger as a guide, very neat.
No problem,

I forgot to say, I used button head screws, as this allows a slight adjustment, where as countersink have no adjustment.

Also depends if you have a little pillar drill, as this way you can get all countersinks to the same depth & how accurate you are in marking & drilling.
TyreFryer wrote:He just wiped around it using the edge and his finger as a guide, very neat.
Never under estimate a craftsman, who makes things look so easy. Masking takes a little longer, but can create a nice job

Posted: Tue Sep 20, 11 12:22 am
by TyreFryer
Good point.

Where did you source your Lexan from Mark?

Posted: Tue Sep 20, 11 12:27 am
by mopar_mark
TyreFryer wrote:Good point.

Where did you source your Lexan from Mark?
Ah . . . I was fortunate that we used it at work ;) as can be quite expensive.

I can ask a few sub contractors I use, what they can sell/buy for me at trade price.

Sheets are generally 6ft x 4ft, probably best to break down sizes to whats required. rear screen, front screen, side windows, etc. This way you can see best way to cut sheet to reduce waste, also easy to transport, etc

Posted: Tue Sep 20, 11 12:34 am
by TyreFryer
Crikey, £424 for a 4mm 3m x 2m sheet: http://www.theplasticshop.co.uk/polycar ... 096-0.html

Posted: Tue Sep 20, 11 12:42 am
by mopar_mark
TyreFryer wrote:Crikey, £424 for a 4mm 3m x 2m sheet: http://www.theplasticshop.co.uk/polycar ... 096-0.html
Said it was expensive :shock: