Changing a windscreen glass ? how easy ?

[Mark w]

My windscreen had decided to star crack whilst on the shelf in the garage . (How on earth did that happen ???)

I am thinking of changing the glass . How easy is it to dismantle the frame and change the glass ? Is it just a case of removing the screws and separating the frame , pulling the glass out and reversing the procedure or is it a pig of a job with mixed results at the end ? 

 

PS anyone know if the glass Caterham sell for £95 is laminated ?( not bothered about the heating element as mine has never been wired in as its interchanged for Aero regularly .) 

[Jonathan Kay]

Someone wrote this up a few months ago. IIRC it was quite simple. But there was also a discussion of appropriate seal thickness, but that shouldn't affect you if you reuse the one you have.

... anyone know if the glass Caterham sell for £95 is laminated ?

... can't imagine it's anything else.

Jonathan

[Mark w]

Thanks Jonathan , the Caterham glass is described as not suitable for MOT , is that because it has to be a heated screen for MOT ? 

Any ideas as to the link for the previous thread ? , i find the search function less than perfect .

[Jonathan Kay]

DIY hints, but this isn't the thread I was looking for.

... is that because it has to be a heated screen for MOT ? 

Someone here suggested that recently, but I don't know. Possibly has to be heated because there isn't a demist function.

The only other reason I can think of is that it's plastic rather than glass. I think that some racers use polycarbonate. And I have seen suggestions to use acrylic, but that sounds like a very bad idea.

Have you got a link for that one at £95?

Jonathan

[Mark w]

 

Link to glass    http://caterhamparts.co.uk/product.php?id_product=2529

[Jonathan Kay]

Thanks

Jonathan

[Roger Ford]

Non-heated glass should pass an MOT without a problem. Car must have "demist" for SVA/IVA but it's not tested for the MOT. Section 6.9 on glazing in the MOT manual (which requires safety glass markings) only applies to class 5 - minibuses, etc. Section 8.3 - Windscreen - is minimal.

So why do Caterham say "not suitable for MOT"? Perhaps they'd rather sell you a heated one. Or perhaps they haven't read the MOT manual. Or maybe they've found something in the tester manual that I haven't.

[Mrp]

Mine was a race car and until last week had an unheated screen and has always passed an mot without problem. 

Mrp

[Mark w]

Thanks guys , has anyone actually had first hand experience of changing it ? 

[TomB]

Ive done it a couple of times, albeit probably 8-10 years ago.  The first time was to powder coat black the screen surround, the second time was to replace scored and pitted original glass with plain laminated glass from a club bulk buy. 

I recall it wasnt too hard, but quiet a tense job as I was so nervous about breaking the glass! I think there are two screws in each corner of the frame that hold it all together.  These screws go into little triangular pieces of ali with threads for each screw.  So you undo these, and gently prise the surround off the glass.  There is the rubber beading, which will either stay on the glass, or it will pull out with the frame.  The flat base comes off very easily, the curved side and top piece is harder - as you are pushing against the bend of the screen surround.  Ease screwdrivers or something like wooden clothes peg halves around it, placing them between the glass and surround as you go so it doesnt pop back.  Work both sides (L&R) of the screen and it will pop off.  There are also a couple of lozenge shaped bits of wood a couple of centimetres long which position the glass in the frame.  Dont loose them!

Refitting is the harder task, especially to do it neatly. You need lots of rubber lube or silicone rubber spray.  Dont use washing up liquid as its full of salt.  I cant remember which way round the rubber channelling goes - whether its fitted on the glass and placed into the frame, or the frame first them the glass.  I suspect the former.  Dont forgot the wooden spacers.  Squeezing it all back together is tricky, and I found the join at the corners of the screen particualrly tricky to close the gap.  I think I might have used a thin bead of black silicone to help seal it. 

Good luck.

PS - do it on the floor, ideally on a carpet or something forgiving.  Don't do it on a worktop, as gravity will be only too willing to punish any clumseyness!

 

 

[Mark w]

Tom 

Thats really helpful . £95 for a glass v £475 for a full screen inc frame means its worth a try .  

[TomB]

It's certainly what I'll do again, unless Im lucky (!) enough to able to do an insurance claim for a broken screen and get the insurers to pay for a heated one! The MOT man has never mentioned the lack of heating elements/ demist ability, as its very much a nice weather, short runs only car at the moment, Ive not had to worry about demisting. I forgot to say, make a note where you find the little lozenge shaped spacers and dont loose them.  I think there are three or four of them and they are just to help position the glass in the frame. Would be worth considering if you want to powder coat the frame or replace any poppers before refitting the glass.   

[Roger Ford]

You could also consider polycarbonate. Steve at YC Plastics makes them. Significantly lighter and unbreakable - and cheaper. Some say they're more prone to scratching, but I never had problems when running one in my race car.

[Superwhite R283]

Im tempted with a polycarbonate one, anyone else in the Hampshire/Dorset area interested? Might be able to combine postage?

[Jonathan Kay]

Are polycarbonate windscreens legal for road use in the UK? A vendor says not.

Jonathan

[Roger Ford]

Define "legal". Will they pass an MOT? Yes. Or at least there's nothing in the MOT tester's manual to say otherwise. Will they conform to constructon and use regulations? Who knows.

Steve posted a summary on the Grads' website when we first introduced them for racing: here

[Baz Hemsley]

My local glazier has replaced the glass in a few 7 frames for me. The glass from Caterham  I have been led to believe is only 4.5 mm. thick and mounted in rubber. I believe the legal thickness should be thicker. I have in the past had thicker glass fitted in black sealer without the rubber. They charged me about £75.