Our aluminium window frames are going dull with white powdery pitting — can they be cleaned/refinished or do they need replacing?

Good news first: aluminium doesn't rust through like steel, so "corroding frames" almost never means "new windows". What you're describing is a finish problem more than a metal one.

What the white powder is: aluminium naturally forms an oxide layer, and the frame's protective finish — either powder-coating or anodising — is what keeps it smooth and coloured. In Dubai's salt air, dust and UV, that finish slowly degrades; once it does, the exposed aluminium oxidises into that chalky white bloom, and pitting starts where salt sits. So it's the coating failing, not the frame dissolving.

Clean vs refinish vs replace: - Light dullness / early chalking → clean it back (a non-abrasive aluminium cleaner, not steel wool), then protect it. A wax/protectant helps it last. - Failed powder-coat, widespread chalking → the frames can be stripped and re-coated / re-sprayed in place — a proper refinish restores colour and protection without pulling the windows out. This is the sweet spot for most of what you're describing. - Deep pitting, corroded fixings, or seized/worn hardware → here it may be more sensible to replace the affected units, especially if the glazing and seals are also tired.

Prevention that matters here: periodic rinsing of coastal/sandy exposure, and specifying marine-grade finishes on any replacements. Systems makers like Technal publish their coating and marine-grade options. Get the frames assessed for clean-vs-refinish-vs-replace before anyone quotes you full replacement — that's standard glass works in Dubai, and a refinish is a fraction of the cost of new windows.