Aluminium windows - already rusting

sk2402005

It seems to be on the weld line, so maybe a contaminated weld?

Dalglish

Oddly the corrosion is on the outside between the glass and the metal frame. A magnet won’t stick to the outer metal frame suggesting it is indeed aluminium and not part steel. What’s puzzling though is the appearance to my untrained eye is that of rust. I’m in west London. 

Dalglish

Yes on close examination, the paint appears to be bubbling in the vicinity of the orange colour. I told  the fitter who visited yesterday it could not be brick dust because of the paint bubbling. To repeat, the fitter unsurprisingly wants this to be cleaned up and left alone. 

ytfcmad

First, your picture is'nt the best, it shows more of the DGU spacer bar than the frame so not easy.
Second, its NOT rust, Ali does not rust, there are parts in the window that could rust but nowhere near where the picture was taken and not inside 3 months.
Aluminium profile is pre treated before being powder coated, normally to around 40 microns in thickness, that's why i asked where you lived, if you're close to the sea then it's normally a marine warranty which means the paint thickness is a lot more.
Occasionally pre treatment isn't a 100% this can lead to bubbling or an orange peel effect, if this is the case you should have it on other parts of the window or other windows as the Ali parts of your windows are cut from 6 metre bars , that said it could of only been a part bar that wasn't treated correctly. 

All the above is irrelevant if you have not been looking after your new windows, all good companies will give you an OEM manual, this basically tells you what and when to clean and the products you can and cant use on the frames etc. If you had one but didn't do as advised then in theory the installer can call any warranty given void, this happens quite a lot in the commercial world. 
There are a lot of things out there that can have a detrimental effect on the frames and glass, even tree pollen as i once found many years ago.

Looking at your picture there is an outside chance its a glass issue and not the frame, that's just based on how it looks in the pic but i doubt it.

Finally, go careful with what you read on this site and thread, there is nothing welded in the manufacturing of an Aluminium window.