Posts Tagged ‘Paints’
The exterior painting for residential homes is more than just painting the home itself. It is about painting all the little details like the shutters, house numbers, outdoor furniture, mailboxes, planters, light fixtures and the porches. The most important part of painting these items is proper preparation before painting.
The same kind of preparations you use for painting the exterior of your home should be used when you paint the other parts of your exterior decor. Drop cloths should be use in the areas where you are painting to protect things that you do not want painted or damaged. Any surface that you plan to paint should be free of cracks, holes, nail heads that may be exposed and the surface should be smooth and free of dirt. Any nails that protrude can be countersunk and the hole filled with wood putty. If there are places where there is old caulk this needs to be removed and new applied. Any really shiny or glossy places can be sanded lightly with fine sandpaper so the paint will adhere easier. New siding will have some mill glaze that needs to be sanded away so the paint will adhere properly.
Salt residue may have gathered under the eaves and this will need to be removed before painting. Also any places where there is mildew this will also need to be removed. After all the preparations are completed, the surfaces need to be cleaned with a soft brush of clean cloth with water so that all the dirt and dust has been removed. Then it is time to do priming. Any areas you are painting that have peeled, worn thin or blistered will need to have a coat of primer. Be sure to let this dry thoroughly before continuing.
Some items that you will be painting, like previously painted downspouts and gutters, will need to have peeling paint and rust that needs to be removed by using a wire brush or scraper. This will leave edges where the old paint was removed so the edges will need to be sanded to make the surface smooth. The garden hose with a strong stream can be used to clean under eaves. After all surfaces are clean and very dry, a primer for metal and wood should be applied. Sometimes galvanized downspouts and gutters were coated with fabricating oil when they were new so this will need to be removed before they can be painted. This will require using a grease and oil emulsifier to remove the oil and then a latex primer has to be applied.
If you have a masonry or brick surface that needs to be painted any efflorescence that has accumulated can be removed with your scraper or wire brush before painting. If the surface has been streaked, there is a problem causing this that needs to be corrected or the problem will return after the new paint is applied. If you are planning to paint stucco or block that is newly constructed you will need to wait a month or two before priming and applying your paint.
Painting your porch floor is an opportunity in incorporate a decorative touch to the look of your exterior by painting the floor in a checkerboard type design. This has been a technique used for years and the look carries timeless appeal. The paint that you apply to porches, steps and patios can be made safer by creating a surface that prevents slipping by adding a small amount of fine and clean granular sand into the each gallon of paint that you apply.
Most paints are mixtures of three main ingredients – a pigment, a binder and a liquid. The colour and opacity of paint are due to the presence of a pigment. This can also impart considerable protection to the other ingredients by harmlessly absorbing otherwise destructive ultra-violet light. The simplest paint is whitewash which once applied is merely a coating of pigment in this case chalk. Whitewash does not offer much protection to the surface beneath it because it does not generally contain a binder (sometimes called a film former or resin). A binder holds the pigment together and sticks it to the surface. Binders are normally solids, so to produce a paint which can be spread over an uneven surface the binder is usually broken up into small pieces and suspended in a liquid.
Paints by use.
An ideal ‘all purpose’ paint should satisfy a number of criteria – it should stick strongly to the surface it is applied to, it should cover well, it should leave a decorative and desirable finish, and should last, particularly when used outside. No one paint performs all these functions well; as a result, paints are formulated for specific uses. For example, when painting woodwork, a three-coat system is usually needed consisting of a primer (to stick to the surface beneath), an undercoat to cover well) and a top-coat (to give a pleasing, durable finish).
Primers and sealers.
These should be used on new or exposed woodwork, brickwork, metalwork, plaster and so on. They will slick firmly to the surface, seal, and provide a key for subsequent coats of paint. They should also be used when you want to paint over sound old paintwork with a new. completely different, type of paint. In this situation, primers and sealers prevent chemical attack between the different paints, reduce the likelihood of the new paint not sticking to the old one and should stop the colour of the old paint bleeding through.
A primer by itself is not permanent protection for the surface below – it should be painted over with an undercoat or topcoat as quickly as possible.
Normally, you use one of these immediately after a primer when building up a paint system, or on old paintwork when you are changing the colour significantly. Undercoats are designed to have: good opacity or hiding power so that you can cover a dark colour with a lighter one without having to apply many coats of paint; a high build capability so that you can put on a thick coat of paint around corners and over sharp edges where paints tend to be spread too thinly; and a soft finish which can be rubbed smooth easily with abrasive paper (ready to lake the next coat).
These are dual-purpose paints providing both a decorative and protective final coat. They are often available in a choice of finishes matte, eggshell, satin and full gloss. The choice of the topcoat affects the overall appearance of the paint system, its durability and its ability to withstand knocks.
Some modern paints, including microporous paints and preservative wood-stains. are designed to act as their own primer on bare woodwork and, often, only one, or at the most two coats are needed.