Estate lighting external refurbishment

[Builder2011]

Hello and thank you for reading this message. Hoping you are well during this concerning time of pandemic.
Not sure if this is the right forum to ask, but standard painting and decorating forum did not seem to be the right place to ask.
The lighting on an estate needs refurbishing externally. Please see photos of an example unit. Is there a product and method that is normally used to redecorate these units?
Thank you again for reading this message. Stay safe.

 

[333rocky333]

A lot of them are a sort of metal, that like yours seems to have some sort of chemical reaction and eventually the coating flakes off, I quess the cheapest option is to wire brush/sand them down and use a Hammertite paint or something similar.
Maybe theres some sort of oxide primer that may help.

 

[flameport]

Probably powder coated originally, and they look like cast aluminium.
Sanding, acid etch primer and a suitable paint finish if they are to be done without removing them.

 

[fluorescence]

As above, all that powder corrosion would need to be cleaned off and then an etch primer used before a suitable top coat. If the top parts are removable, it may be easier to take them all off & get a paint shop to media blast & refinish them in something suitable?

 

[Lectrician]

These where known as Churchhouse Bollards, originally from Crompton, then taken over by Eaton. They were one of the highest quality fittings spec'ed by councils for schools and open public areas. Bullet proof. I would strongly advise looking after these and would rarely advocate painting fittings, but in this case, there is little that can replace their resilience! They may well benefit from a control bypass and the introduction of an LED lamp at the same time as the painting.

I have no idea how easy it is to remove the paint and repaint aluminium, but it's worth a shot! These bad boys are the best bollards out there, and miss them!

 

[Builder2011]

Thank you for your replies!

 

[SimonH2]

As above, see if they will come apart - dealing with the bits in isolation is a lot easier than doing it in-situ. However, my experience is that things like this made from ali will not come apart. After a short while, all the screws will be well and truly stuck and your chance of getting them out is on the low side of none. Still assembled it's going to be impossible to grit blast and paint round the edge where it turns in above the glass. That means you'll get corrosion still there and it will creep out under whatever coating you put on it - lifting it off as you can see it's done to the original coating.
If you do have to do it still assembled, then do what you can and give everything a good dose of ACF-50. You might be thinking "it's just another anti-corrosion, but having used it myself, it's the nearest thing to a miracle liquid you'll find.
Years ago I had a share in a small aircraft - several thousand rivets flying in close formation One year duing it's annual inspection they spotted corrosion on the tail plane. Paint lifting off in lines along the joints between panels. They charged us a fortune to rub it down and spray it, then next year ... corrosion again in the same places. It just came out from in the lap joints, crept along under the paint, and lifted the paint off. When the proposed to do just the same again, we suggested an alternative and had them take it off. I took it home, stripped it all down to bare metal, blasted off the corrosion (using olivine which is a soft mineral so doesn't cause as much damage, especially if it gets into bearings etc), then had a paint shop do it properly with etch primer. Then I made up some lances and sprayed it internally with ACF-50. By the time I got it back to the workshop, there were nice tell-tale pink lines along all the joints - and when we sold the aircraft a few years later, not a hint of corrosion.
As I had some left, I stuck a bit in the bulkhead on the Land Rover. It was rusting nicely in all the usual places and I was waiting for the MoT guy to pick up on it sooner or later. When I sold it 10 years later, the rust had not got any worse - I was well impressed.