How to Paint Woodwork

How to Paint Woodwork

How to Paint Woodwork  If you are using solvent-based paints, plan to decorate windows early in the day to make sure the paint will be dry enough to close the windows by nightfall. Finish with the skirting boards, in case you touch the floor with the brush and specks of dust get transferred to other areas. As a precaution, slide strips of thin card under the skirting to act as a paint shield (don’t use newspaper; it will tear and remain stuck to the skirting).

Essential tools:

  • 12, 25 and 50mm (1/2, 1 and 2in) paintbrushes
  • Paint kettle
  • Sharp scraping blade


Using solvent-based paints

The familiar solvent-based paints (oil paints) are available as high-gloss and satin finishes, with both liquid and thixotropic consistencies. Indoors, they last for years with only the occasional wash down to remove finger marks. One or two undercoats are essential.

A one-coat paint, with its creamy consistency and high-pigment content, can protect primed wood and obliterate existing colours without undercoating.

Apply it liberally and allow it to flow freely, rather than brushing it out like a conventional oil paint.

Low-odour, solvent-based finishes have largely eradicated the smell and fumes associated with drying paint.


Fast-drying acrylic paints

Acrylic paints have several advantages over oil paints. Being water-based, they are nonflammable, practically odourless, and constitute less of a risk to health and the environment. They also dry very quickly.

Provided they are applied to adequately prepared wood or keyed paintwork, acrylic paints form a tough yet flexible coating. However, acrylic paints may not dry satisfactorily if they are applied on a damp or humid day. Even under perfect conditions, don’t expect to achieve a high-gloss finish when using acrylic paints.


Applying the Paint

Prepare and prime all new woodwork thoroughly before applying the finishing coats. Wash down old paintwork with a sugar-soap solution and key gloss paint with wet-and-dry paper.

If you are using conventional oil paint, apply one or two undercoats, depending on the covering power of the paint. As each coat hardens, rub down with fine wet-and-dry paper to remove blemishes, then wipe the surface with a cloth dampened with white spirit.

Apply the paint with vertical strokes, then spread it sideways to even out the coverage. Finish with light strokes (‘laying off’) in the direction of the grain.

Blend the edges of the next application while the paint is still wet. Don’t go back over a painted surface that has already started to dry, or you will leave brush marks in the paintwork.

Use a different technique for spreading one-coat or acrylic paints: simply lay on the paint liberally with almost parallel strokes, then lay off lightly. Blend wet edges quickly.


Preparing Woodwork for Paint – Problem surfaces

SURFACE

TREATMENT

New bare wood

Look for cracks and blemishes which need filling. Use fine surface filler for interior wood and a waterproof wood stopping or epoxy-based wood filler for exterior timbers.

Apply knotting to all visible knots to stop resin bleeding from them.

Smooth the wood by hand, using fine abrasive paper, working only with the grain. Alternatively, use a drum sanding tool or flapwheel in a power tool, again working with the grain. Be gentle because with power tools even the finer grades of abrasive paper remove wood very fast.

Old bare wood

If there are signs of damp rot – soft patches easily penetrated by a penknife blade.

Fill all cracks and gaps with filler as for new wood. When set, smooth with fine abrasive paper.

Do not leave wood unprotected for any length of time, especially if it is outside. As soon as preparatory work is complete, apply a coat of wood primer.

Painted wood

If the paint is sound and in good condition, do not strip it unless too many coats are causing an obstruction – making windows hard to open, for instance.

Clean down with sugar soap and water. This removes dirt and keys the existing paint so that new paint will adhere to it.

Keying (roughening a gloss surface very finely) is essential: without it new paint is easily damaged and scratched off.

Where the paintwork is slightly damaged but is mainly sound, only work on the damaged areas. Rub with a damp flexible sanding pad to remove all loose material, wipe clean and allow to dry. Prime bare wood where it is exposed. Then lightly rub the whole area with very fine abrasive paper and wash with sugar soap, as for sound paintwork. Fill small chips and stripped patches with fine surface filler. If these are not filled, a depression will show in the finished paintwork, especially when the paint layers are thick.

Varnished wood

Use a chemical paint stripper or varnish remover to get back to bare wood.

Stained wood

If the wood is to be painted and the stain is old, rub down with a flexible sanding pad. If the wood is to be sealed to give a natural finish, remove the stain with a wood bleach. Follow the instructions on the can.

Wood treated with Preservative

As long as the preservative is old and dry, paint primer over it. If the coating looks fairly new, unless you know it can be painted, coat the wood with an aluminium primer-sealer. Otherwise the preservative may bleed through.

08. December 2010 by admin
Categories: Decorating, Painting | Tags: | Comments Off on How to Paint Woodwork

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