Does anyone know how to do a nice job of painting one of these office type modular ceilings that are favored in a lot of Thai house as a second false ceiling? Probably best I don't start sanding the aluminium, so not sure of spray painting is the way to go...

A suspended gypsum board ceiling with exposed aluminum T-Bar? If so, remove the panels and spray paint them. Reinstate the panels after a day of drying.

I hated the office like feeling in the house.

i removed the gypsum boards.

Bought the large gypsum boards (122x244 or was it 125x250) screwed them on the aluminium profiles. Fill in where the edges meet to make a smooth finish.

No more profiles in sight. On some places i had to make sure i could access electricity and water connections. For that i just made a small are removable.

You need a pair of extra hands to make it easier and a lot quicker. About 80m2 in a day is possible using the existing aluminium profiles.

A suspended gypsum board ceiling with exposed aluminum T-Bar? If so, remove the panels and spray paint them. Reinstate the panels after a day of drying.

Not sure if that's the right pro description, but basically an alu grid with white gypsum tiles (approx 40x40cm or something).

I've seen people simply splash a layer of white paint over both tiles and alu, which obviously looks a bit sloppy.

I think the tiles themselves could be cleaned. But for consistency I was looking to paint both them and the alu.

The suggestion about attaching larger tiles/boards seems attractive. The long term idea was to replace the ceiling in a similar way. Not sure if the alu will hold larger tiles though. Even the current small ones seem quite heavy.

Here is suggestion you may consider. Fill in all the cracks between the ceiling tiles and the aluminum frames, and between the ceiling tiles and the walls, with wall putty. Paint the aluminum frames with a white primer and then paint both the tiles and the frames in your preferred colour with a hand brush. It takes a little bit of time to do the job properly but the end result is well worth the effort. If done properly it will look like an 'artexed' ceiling and very impressive.