All unfinished wood or bare wood surfaces should always be primed prior to painting. This goes for both interior and exterior paint projects. The reason you cannot skip bare wood priming is that wood is porous and has a grainy surface. Because primer contains high solids, it helps fill grains in the new wood.
If you are deciding to paint bare wood, you should seal all knots (spot prime) with a shellac based primer. Shellac based primers are great for sealing wood knots and sap streaks. They do carry a pungent odour, but dry very quickly and will not let the knot bleed through the top (finish) coat.
If you paint bare wood such as cedar siding before priming, the paint can lift or peel off because it has nothing to adhere to. This will result in disaster, the paint will chip or flake off and will not stand the test of time. There are oils and tannins in the wood that can bleed through.
The best rule to adhere to is to apply at least two coats of sealer directly onto the raw wood. This will protect the wood and create a barrier. Then apply primer to enhance adhesion, return tooth to the surface, and whiten the surface for optimising paint colours you plan to apply over it.
As you may know, a canvas must be properly prepared before it can be painted on. The same is true for any wooden surface. Both canvas and wood will absorb paint if they have not been properly prepared beforehand, leaving dull colors as a result. A primer will fill all the small gaps present in the surface.
What happens if you don't prime bare wood is not pretty. Similar to new drywall, raw wood soaks up paint like a sponge. As a result, your surface will look blotchy since pores in the woodwork unevenly absorb the paint. More importantly, the painted wood will likely peel in two or three years without primer.
With fresh drywall, the substrate actually absorbs a coating really well, like a sponge. However, because it absorbs so well, without a primer coat, you'll experience uneven coverage, especially along drywall seams. This means you'll need to apply more paint to finally get an even coat.
Milk Paint is the Best Paint for Raw Wood! We all love the chippy goodness that can be created with Milk Paint, but it looks just as gorgeous on raw wood. Because it soaks in similar to a stain, Milk Paint is THE best paint to use on a raw wood surface with no existing finish.
If sanding is your least-favorite step, then it's certainly possible to paint furniture without sanding. But to do so with favorite results, you should clean the wood's surface AND use a high-quality primer and/or paint.
You may or may not need more than one coat, depending on the paint type you choose. If so, it's vital to let the first coat dry properly first or you'll make an awful mess of it. As a general rule, two coats deliver a better sheen and a deeper, fuller finish than one.
A: Yes, before you paint unfinished furniture, it's worth going through the process of sanding and priming. I recommend the following procedure; though a bit tedious, it ensures satisfactory results. Start with some rough sanding.
Because stain seeps into the wood, it's more protective than a coat of paint which is a coating that simply sits on the top of the wood. Solid stains look almost identical to paint but are more protective to the wood because they seep into the porous wood fibers.
However, if you are painting a brand new wood such as a door you will need a primer as the first coat to seal the wood ready for the undercoat. There are primer/undercoat paints that act as both, such as Dulux Trade Quick Drying Primer Undercoat that is ideal for a base layer or two on bare wood.
Clean the Wood Surfaces
Dip a cloth in the water, firmly squeeze it dry, then wipe down the wood to remove all oils, dirt, and grime. Rinse the surface with clean, warm water and a clean cloth. Let the wood dry completely. After the wood is dry, check the piece for large nicks, gouges, and scratches.
You'll still want to sand it even if you do remove finish chemically, so you can sand out any scratches or light damage to the furniture and get it ready for a coat of paint or stain. However you plan to finish the piece, the paint or varnish needs to be applied to bare wood for best results.
MINERAL PAINT (My Favorite Option)
It'll adhere to just about anything. As an added bonus, Fusion paints are so durable they are waterproof, stain resistant, and don't even require topcoat. I do recommend lightly scuffing the piece, but no heavy sanding is needed for best results!
If you're painting wood without a stain or finish, use a latex or an oil-based primer for the best results. Don't over or under apply the primer: You should aim to apply two coats of primer to your wood's surface. Brush the primer on, and allow the first coat to dry completely before adding the second coat.
A paint and primer in one is not designed for every project. Some surfaces require specialty primers that block out color, have higher adhesion qualities or handle corroded surfaces. Exterior surfaces such as wood and metal require a primer for proper adhesion and blocking power.
On new drywall, you will use 3 coats of the finish material instead of a primer coat plus 2 coats of finish. Most projects where you're going over a previously-painted surface do not require the use of a primer.
Typically you can use almost any white paint as a primer, but there are a few things to be mindful of. I recommend using a can of flat or an eggshell white paint as primer.
Use It as Base Coat or Primer
“If you use it up, you will probably save yourself from buying more of what you're putting on the walls, and there's no need to bring it to a paint recycling center,” Fresina notes.
If an undercoat or top coat of paint is applied to bare wood, the moisture is "sucked" out of it too quickly and the paint itself does not get a chance to soak into the timber. The paint therefore dries on the surface and has no "roots" so to speak – it will quickly peel.