paint over old damage
I will tell you the correct and easiest way to repair that area:
first prime the spot with a stain blocking primer. that will seal everything up and prevent old water stains from bleeding through your repair. Let the primer dry overnight if you have the time.
now all you have to do is patch it with Durabond or joint compound. Durabond is mixed with water and dries very fast. it comes in 5, 20, 45, & 90. the higher the number the longer you have to work with it until it sets up. 5 = 5 min, 20 = 20 min and so on. hot water makes it set faster.
now the trick is if you are not experianced with plaster is to put on thin coats. if it is the size of a dinner plate you should use a 6" or 8" mud knife for your first coat. let it set up and scrap off the ridges and high spots. use a 10" or 12" mud knife for each additional coat. (you can get away with a 12" for everything if you know what you are doing).
Remember, it is easier to apply 2, 3 or 4 coats of plaster vs sanding off a pancake.
then just sand spot prime and paint.
now if you really suck at plaster - after you think you are done sanding prime it and look at it. if it looks wavy or sunken in you have to apply more coats and sand again. if it looks like a hump you have to sand through the primer and plaster, mud again, sand and prime.
Last edited by NAV; 08-12-2009 at 03:36 PM.