There is nothing like a fresh coat of paint to spruce up a place, and when it comes to brand new homes, furniture and other structures, paint really adds the finishing touches and makes a project look complete. It's all an integral part of home decorating.
Professional painters know how to do it right, but if you’re an amateur, you’ll likely need a few tips to ensure the results are what you want and the finish will last. After all, you don’t want to be doing a repaint after just a few short months.
Preparing the surface correctly prior to painting is probably one of the most important tasks in the entire painting procedure. It’s what will produce a great finish and one that will last.
Varying types of surfaces will require different methods and procedures for preparation to get it right, and this post provides these basic procedures for some of the most common surfaces.
Brand New Woodwork and Timber
As all timber is not the same, a different type of primer must be used for different wood types. Softwoods, such as pine, will require a primer coat containing more oil. Pine is a rather porous wood and will absorb oil readily.
Hardwoods are very closed-pored and are often greasy when new. Therefore, the primer for hardwoods must be thinned with something like mineral turpentine or a more organic alternative.
Be sure the timber to be primed is dry enough. Often new timbers are still quite damp so give it enough time to dry out properly. The timber will probably require a light sanding first, followed by the removal of debris with the aid of a dusting brush.
All knots and resinous veins in the wood should be sealed with a suitable knotting material, such as a dab of alkyd resin exterior undercoat. The surface can then be successfully primed.
A healthier and more environmentally friendly alternative is to employ the use of an acrylic primer. Water-based primers tend to be less absorbent on porous woods. Also, they don’t emit toxic fumes. Kind to you and the environment.
Previously Painted Woodwork and Timber
If the surface is in a reasonable condition, it will need only washing and a light sanding to remove grime and debris and scuff up the surface for effective adhesion of the new coat of paint.
However, if the surface suffers from blistering or flaking paint, the affected areas must be sanded smooth and spot primed. The entire defective paintwork must be removed if large portions of the surface are affected.
The best way to achieve this is to burn the paint off with an LP gas burner. After burning off, the surface must be sanded smooth, dusted off, and then primed.
New Concrete Work
A new concrete surface should be allowed a minimum period of at least three months to dry out before painting should be attempted. If not, there is a chance moisture will rise beneath the paint and make it bubble and peel off.
The surface should be washed with a solution of zinc sulphate and then sealed with a concrete sealer. This procedure mainly applies to oil-based paints. Acrylic paint can be applied immediately after the drying out period and is one of the preferred types of paint for new concrete work.
Previously Painted Concrete Surfaces
All peeling and flaking paint must be removed. A stiff wire brush usually accomplishes the job successfully. This should be followed by a thorough washing down of the surface to get it nice and clean. If the surface is chalky or powdery, a binder-sealer such as Binderol should be applied before painting with the top coat.
New-Set Plaster and Fibrous Plaster
Newly-set plaster surfaces should be allowed a drying out period. As lime is a problem in new-set plaster, a coat of zinc sulphate solution should be applied as with concrete. If painting with an oil based paint, a pigmented sealer will be necessary as the initial coat. Acrylic paint may be applied directly.
Previously Painted Set and Fibrous Plaster
The surface should be sanded and a coat of cement sealer applied before attempting to paint with an oil or enamel paint. Flaking paint must be removed and the patches filled with spackle or polly filla. If painting with acrylic, the surface need not be sealed as acrylic paint is an effective sealant.
New Iron and Steel
A rust-inhibitive priming paint must be applied to ensure thorough protection of the metal. All dirt and grease should be removed before priming to ensure effective paint adhesion. After coating with rust-preventative paint, the surface must then be coated with a suitable metal primer.
After that, your finish coat can be applied.
Previously Painted Iron and Steel
If the paint is cracking or flaking, it must be removed by sandblasting or flame cleaning. Or at the very least, a metal scraper and a thorough sanding. If it's only a small job, the use of a paint-removal substance is all that is needed.
Rust must be removed with a wire brush and the affected areas rust-proofed and primed with metal primer. The entire area should be wiped clean with a rag dampened with turpentine or natural cleaning alternative, such as a mixture of white vinegar and water to wash down the surface.
An oxide coating forms on new aluminium surfaces and this coating generally protects the metal. This film, however, offers no resistance to acids, alkalis and salty air. These substances will corrode the surface, so the surface should be cleaned and slightly roughened employing the use of steel wool. The primer coat should be zinc chromate. The surface can then be painted with the selected finish.
Copper offers the highest natural resistance to oxidation and weathering of most metals. However, if situated in a corrosive atmosphere, the copper surface should be cleaned and slightly roughened as explained with new aluminium, and primed with a coat of zinc chromate.
Previously Varnished Or Lacquered Surfaces
When re-varnishing a surface, it should be cleaned with turps and steel wool, rubbing with the grain, and dried with a clean rag before the turps has dried.
If you are planning to paint the previously varnished surface, it will require thorough sanding and then a coating with a stain-sealing undercoat such as Bleedseal.
If all these preparation procedures are adhered to, the result should always be a durable and long-lasting painted finish.