What you’ll need
Step by step
Prepare and clean the wall
The wall must be cured, sound and clean — remove loose plaster, dust, grease and any flaking old paint. Fill large hollows or cracks separately first; putty is for a fine finish, not deep filling.
Dampen the surface
Lightly dampen a very absorbent wall so it does not pull water out of the putty too fast, which causes powdering. The surface should be damp, not wet.
Mix to a smooth, lump-free paste
Add SUMO Wall Putty to clean water (powder into water) and mix with a paddle to a smooth, creamy, lump-free consistency. Let it stand a few minutes and remix.
Apply the first coat thin
Spread a thin, even first coat with the blade, working it into the surface. Keep it thin — thick putty coats are prone to cracking. Let it dry.
Sand, then apply the second coat
Lightly sand the first coat to knock off ridges, dust off, then apply a second thin coat to fill the remaining fine imperfections and level the surface.
Final sand, then prime and paint
Once dry, give a final light sand for a smooth finish, remove all dust, and apply a primer before painting for the best, longest-lasting result.
What to avoid
Thick coats crack and debond. Build up in two thin coats instead.
Putty over dust, grease or flaking paint peels. Clean and make the wall sound first.
A thirsty wall dries the putty too fast and it powders. Dampen it lightly first.
Priming over putty evens porosity and improves paint adhesion and coverage.