Paint the wall in Hong Kong

[jobin]

Will be soon prepping and painting an interior wall here in Hong Kong where the walls are brick covered with some kind of plaster then painted. If i now scrub the wall with a rough green scrubby the wall paint and plaster just melt away, as if chalk. Some times the paints here are poor grade Chinese and really do 'melt' away. Regardless of the past i want to do a good job using top quality emulsion paint but am uncertain how to best prep the wall.
Should i wet scrub and remove all the old which will leave the brick work- a massive job. Maybe sand lightly then damp cloth then thin primer, paint etc. Have read vinegar/water can seal up the old plaster-true? Any ideas?

 

[ladylola]

Just a thought but are you sure the finish is paint rather than some sort of limewash or distemper? If it is then really you would need to go over with a similiar product rather than an emulsion paint.
You should really be using anything too abrasive on the walls , just enough to remove anything loose or flakey really, it sounds like you are rubbing hard enough to cut a new window in the brickwork

 

[jobin]

And how to determine the difference between old emulsion paint and limewash/distemper?? Also, did you forget to include a negative word in your reply. Thanks for the ideas and i will press on, but not too vigorously.

 

[TheDec]

jobin,

Being what could be determined as living a long way away, it would be difficult for anyone here to offer you the correct advice, the simple reason for this is we would be unaware of what products you could purchase in order to solve your problem. Judging from what you say I would be of the belief that you are dealing with a casein borne oil based distemper.

So if you are looking for help you should post some pics and also tell us what products with regard to purchase you have to your disposal, and for the time being make no attempt to either wash or sand the substrate.

Dec