5 replies to this topic

[Aridgerunner]

The MKIII I'm working on has the swing out quarter lights. The glass in them is terribly scratched and I need to replace it. Getting new glass shipped from the UK to the USA is expensive and there is no guarantee against breakage. I found a vendor that sells polycarbonate windows for Mini's.

My questions are, has anyone one this forum done this, and if so what tricks are involved?

Thanks in advance.

Bill

[evansisgreat]

This is a useful video. I also plan on putting polycarbonate into my rear opening windows, but for weight saving. 

 

[Ethel]

It's flat toughened glass so it ought to be possible to get it copied locally. I wouldn't know about the cost though, with the rounded corners.

 

Poly-carbonate is certainly an option & you can get anti scratch coatings or films. Working it is much easier, so it could be even easier to find a local supplier to copy the existing glass.

[alpder]

Polycarb comes in 'plain' and 'hard-coated'. The plain stuff may or may not be UV stabilised. The hard-coated can be both sides or only one, but it will usually be UV-stable.

 

I've used 5mm both plain and hard-coated polycarb in teardrop trailer glazing. The plain marks very easily. The hard-coated is remarkably scratch-resistant.

 

I've cut my own - by CNC and also simply with a jigsaw. I've also had polycarb professionally cut and E-marked (i.e. certified for vehicles - similar to USA DOT marking I guess) here in the UK.

 

A 5mm-thick polycarb oval panel approx 2ft a 1ft has some flex. On my teardrops, I glue them in so there's no seal to worry about and no security worries. But in the Mini the quarterlights are held at three points (hinge, hinge, catch) and presumably the glass provides much of the rigidity, so will the flex mean they won't compress the seal enough, or maybe even allow someone to pop them out of the frame?

 

So maybe chat with the vendor about:

 - Is the material hard-coated (both sides)

 - Is it UV stable

 - Are they DOT marked and, if not, will that be a problem with authorities where you are.

 - Are they suitable for swing-out quarterlights, or only for fixed ones.

[Aridgerunner]

Alpder, you bring up some very good points, exactly what I was looking for. The "authorities" won't know, and wouldn't care if they did know. Because this car will be licensed as an antique there will be no state inspection (your MOT) required.

I will address the other concerns with a few vendors.

Thanks!

[TristanMini]

I’ve seen people do this before—using polycarbonate instead of glass for the Mini quarter lights is definitely doable, and it’s actually a pretty common workaround, mostly to avoid the hassle and cost of shipping glass.

That said, PC does have its downsides. It scratches pretty easily and tends to haze over time unless it’s a hard-coated version. Also, during installation, you don’t want to clamp it too tightly—leave a bit of room for expansion or you might end up with cracking issues.

For a daily driver, I’d personally still prefer glass. But for a restoration or a more practical/cost-driven build, polycarbonate is a reasonable option.