Stripping Paint and Painting Preparation
Strip paint only when there is no alternative. It is a tiring and time-consuming task. If the fault — blistering, flaking, etc. — is confined to small areas, you need to strip only the faulty section.
Do not strip paint just because a surface has been painted a number of times without being cleaned down. Very often the more coats of paint there are on a surface, the better protected it will be.
There are times when the paint must be stripped off in order to get a reasonable final surface. You can strip by scraping, burning off or using a chemical stripper. Each method involves hard work.
Using a scraper, without the aid of heat or chemical, is very difficult, and is a technique that should only be employed on small areas.
A good scraper to use is the Skarsten type which has two blades — one serrated and the other plain Use the serrated blade to score the surface, being careful not to go too deep; then use the plain blade to remove the rest of the paint. Use a shave hook for scraping mouldings.
Burning off woodwork
Burning off is the quickest way to strip woodwork. The best way to apply the heat is with a paraffin orblowlamp, although electric paint strippers are available.
Play the flame backwards and forwards across the surface. The idea is to melt the paint but leave the surface underneath untouched.
As the paint shrivels up, scrape it off, being careful not to let it fall on to your hand.
Keep a container on the ground to catch the melted paint.
Work from right to left if you are right-handed, and the other way round if you are left-handed.
For stripping mouldings, start at the top and work downwards, using a shave hook. On flat surfaces, work from bottom to top. When working on a moulded door, strip the mouldings first.
Make a habit of turning the blowlamp flame away from the surface while you are scraping; this way you will not bum any ‘holes by accident.
Do not use a blowlamp on metal, asbestos sheeting, plaster walls or close to the glass in window panes.
Any charred patches on woodwork must be rubbed down, as paint will not adhere to them.
Electric strippers are much slower than blowlamps and they must not be used on damp surfaces.
Always remove curtains from windows before stripping paint — whether you are working indoors or outside.
Take care when stripping fascia boards to move any birds’ nests or roofing felt out of the way — otherwise they can suddenly catch fire.
Do not use a blowlamp near thatched or wood shingled roofs.
After using a blowlamp, rub the surface thoroughly with medium glass-paper, knot, prime and apply stopping.
This method of stripping allows you to scrape off paint right up to a glass pane without cracking it. It can also be used on metal and plaster.
Chemical strippers vary in their suitability for different jobs. Ask the advice of your retailer, and follow the instructions on the tin carefully.
This is particularly important if you are applying chemical strippers to metal, as some types may attack the surface.
Most of these strippers burn skin badly, so wear rubber gloves. Wear old clothes, too, and move anything which might get splashed.
When the chemical has done its work, strip off the paint with scraper and shave hook. Wrap stripped paint in newspaper and burn it immediately.
Do not leave the stripper can open or in a place where children might get at it.
After stripping, thoroughly clean the surface with white spirit and rub down with sandpaper. All traces of stripper must be removed, as any which remains will react against new paint.
Wood. Sand the surface down so that it is quite smooth. Apply knotting to any knots and resinous patches, to prevent resin from `bleeding’ through the paint. Seal the surface with primer. Certain woods, including teak, cedar and resinous West African timber, require special primers.
Plaster, concrete and brick. In new houses. Allow a 12-month drying-out period before you apply any oil-based paint to these surfaces. If you do not want to wait 12 months you can put on two coats of emulsion paint as a temporary measure. Emulsion paint allows the surface to breathe, and the wall can continue to dry out.
During the drying period, salts in the plaster and concrete cause a white surface deposit called efflorescence. This deposit should be wiped off, as it occurs, with a dry cloth.
Metal. Iron and steel must be thoroughly wire-brushed, scraped or cleaned with emery cloth to remove rust, then be primed immediately. Allow new galvanised iron to `weather’ until it is dull before cleaning and priming. Clean aluminium and copper with fine glasspaper and white spirit before priming.
Hardboard and wallboard. Make sure that the surface is perfectly clean and dry. Prime the surface and fill all pin andholes before painting.
Primer. A primer is essential on new unpainted surfaces that are to be finished with oil-based paints. Priming is not usually necessary for new surfaces that are to be finished with emulsion paints.
The type of primer you use depends on the surface you wish to paint. All-surface primers are also available.
All set for painting
Before you start decorating a room, try to finish off all the odd jobs that need doing, such as replacing broken sash-cords, fixing badly fitting doors or having chimneys swept. If you leave these jobs until later, you will almost inevitably make a mess of your new paintwork.
Move the lighter pieces of furniture out of the room and stack the heavier pieces in the centre under dust sheets. Remove carpets and curtains and cover the floor, too, if it is tiled or of polished boards.