Before skim coating, prime the wall with paint primer. Priming prepares the surface and seals loose drywall paper. Apply one to two paint primer coats to the wall or ceiling.
Before you skim coat, remember to dull the surface with sandpaper and remove any sheen from the paint. This provides the skimcoat with a surface to which it can adhere.
Clean first, sand next to give the surface a ``tooth'', them skim coat and sand as many times as necessary to get the quality of finish desired, primer (PVA) and then top/color coat.
Plan is to clean walls with TSP and knock off current texture with scrappers. Sand walls with 120 grit. Clean the dust off with wet sponges. Then apply KILZ original primer. Apply second layer of all purpose joint compound. Then sand walls w/ 220 grit. Clean with wet sponges. Finally KILZ PVA primer. Paint.
For newly skim-coated walls, use a high-quality PVA (polyvinyl acetate) drywall primer. This type of primer is designed to seal the surface, provide a good base for paint, and ensure even coverage. It's specifically made for new drywall and skim coats, so it should work well for your needs.
Walls with a skim-coat will need a full coat of primer. Patched areas should be spot-primed before painting too, so if you've filled in nail holes or patched dents, be sure to prime those spots after sanding.
USG Sheetrock® Brand All Purpose Joint Compound is a best-in-class solution for embedding tape with superior filling and finishing qualities and is an excellent choice for skim coating.
Cons of the Skim Coats
Skim coating walls seems to be more tedious than expected. It can consume more time for those who aren't familiar with the steps used to repair walls. This process can also be intensive labor-wise and energy-consuming.
There's no one answer because the number of coats of primer depends on a few factors, such as the color you're painting over, the type of paint you're using, and the condition of the walls or surface you're painting. However, two coats of primer are typically used for most projects.
A skim coat should be applied in thin, even layers. Each layer should be no more than 1/16 to 1/8 inch thick.
Application/Usage:
Brush down highly polished surfaces with a stiff bristle brush before priming. 2. Apply 2 coats of BAL Bond SBR using a clean brush from a container, diluted or undiluted as appropriate (See USAGE above). Allow to dry between coats.
Before you can paint a newly plastered wall, you need to add a primer and undercoat. If you skip this step, the plaster will soak up the paint like a sponge, so you'll need to add more coats than you might otherwise need to.
Give the final coat a full day to dry, then you'll sand the drywall for that ultra smooth finish. In color, it may not look perfectly even, but as long as it's super smooth, the primer will do the trick to even the color prior to paint.
Usually, two coats of PVA mixture will give you the best surface for skimming before plastering. Instead of PVA, you could use a bonding agent.
PVA primer: PVA (polyvinyl acrylic) primer is a water-based primer that is specifically designed for use on new drywall.
What tools and materials do I need for skimming a wall? You'll need skimming plaster, joint compound, bonding agent, trowels, a hawk, corner trowels, a feather edge, a paint roller, and a squeegee knife.
If the paint is in good condition and not in need of any maintenance, it is perfectly fine to skim over it with plaster. However, if the paint is old, flaking, or damaged, it is recommended to remove it before plastering.
3. Clean and prepare your walls. Before you start skimming, you'll need to make sure your walls are clean from dust and that any cracks have been sealed. This will help you achieve a smooth finish with as few coats as possible.
The first alternative is to use joint compound rather than skimming the surface with plaster. The compounds are for filling joints between plasterboard or any gaps and holes. However, you could use it to give an entire wall a smooth coat. You apply it with a trowel or putty knife.
You don't have to sand between coats; just knock off lumps or proud mud lines with a 5- or 6-in. putty knife to avoid streaks in the next coat. Brush off the wall and you're ready for the next coat.
For this, I use drywall joint compound, either pre-mixed USG or the type you mix. Either works fine. A one-gallon bucket of drywall compound can skim coat a wall at least 75 sq. ft.
Spackling is sometimes mistakenly used as a skim coat. But spackling isn't made for this application – it dries too quickly, doesn't spread smoothly and is hard to sand* to a fine finish on large areas. So, when looking for a smooth, paintable surface, let the spackle do its job: repairing small damage.
The supplies you need to skim coat your walls include: joint compound, a sanding block, a bucket for mixing, a drywall knife and a mud pan. (I also recommend a drill with a mud mixer paddle attachment). A big ole' bucket of joint compound costs about $20 and this kit with all the tools you need is under $50.