Mildew type covering on front composite door handle - how to treat?

Movie Maestro

Hi all,

My north facing composite front door handle has what looks like some kind of blue/green mildew all over it. Has anyone seen this before please and know what is the best treatment for it thanks?

Any advice welcome :)

10-10-20

That looks like the brass-effect coating is wearing off allowing the metal under it to oxidise.

Replacement might be the only fix for the bright-work.

Are you near the sea? If so ask about more durable finishes. Sorry!

Movie Maestro

Thanks for the quick reply and advice, no not near the sea at all. I was hoping it would be fixable ☹️ The front letter box is not great either as you can see ☹️ This started happening a couple of years after the new door was installed, I would have expected it to have a more durable finish.

Alun

Not mildew, as said above, it's the copper in the brass plating that's corroding and causing that blue-green colouration. You might be able to temporarily improve the look slightly with some good quality metal polish, but long-term I'd start looking at a replacement.

Movie Maestro

Cheers Alun, that makes sense alright, thanks for the feedback, looks like a replacement is probably the best way to go.

Alun

The problem is that there's a lacquer coating to stop the brass tarnishing and needing constant polishing, plus it's not solid brass anyway so polishing it would rapidly result in the plating wearing away. The lacquer pits, moisture gets in and you get corrosion. It's particularly prevalent in coastal areas but other airborne pollution can probably cause pitting as well, such as soot from wood / coal fires.

10-10-20

I'd guess that the letterbox is extruded aluminium with the copper/brass plating on top. It suffers from that type of surface bloom/oxidation which creeps under the layers. As Alun says, if you touch it, it will all fall away.

jack of all

+1 on above, you can get a powder coated fittings that may prove more resistant to oxidation, or look at PVD brass, but may not be available to suit your door.

Movie Maestro

Cheers for all of the feedback, it's VERY much appreciated!