Paint Types in House Painting
Choosing your paint is probably the most important thing you will do on your project. This is because most paints are designed for a specific purpose. Primer paints are designed to adhere to raw surfaces and then to stick to a protective coat over the top of it. In general, there are four types of raw surfaces that you might want to paint over, wood, masonry, drywall, and bare metal. You should be able to find a primer that will work on your bare surface. Don't be tempted to simply skip the primer coat as finish paints will sometimes not stick well to the surface, especially metals.
The big question for many painters is whether they should use oil or water based paints. Glossy oils tend to be more impermeable to water and will bubble up if the surface beneath is damp. Latex and other water based paints will make wall paper peel. Industry experts have argued for a long time over which formula is better in general. For exterior applications water-based paints have got the upper hand. Besides allowing the house to breath, they tend not to crack as readily. Also they have the great advantage of water clean-up. Also, if you are worried about the ultimate environmental impact, water-based paints tend to be more friendly to the eco-system. Oil paints usually have a stronger and more overpowering odor. You should always ventilate well when painting, but it will seem even more vital with oil-based paints.
Even so, oil is often the choice to make, especially when painting over a surface that was previously painted with an oil base. If you simply must use a water-based paint over an oil-based paint, you should sand down the finish then prime it so that the paints will adhere to each other.
Although the price is not always the best indicator of quality, it does serve as a good general guideline. Also, the warrantee on a paint will indicate how long it is likely to last. Remember that even inexpensive paint is relatively cheap when compared to the amount of time it takes to apply it. Better to have a durable paint that lasts a few extra years than a cheap one that gives out in less than five years.
Pigments in paints also make a difference. Cheaper paints often have cheaper pigments, so they tend not to cover as well, requiring more than one coat. Here again labor is a factor. Two coats of a paint that costs you half as much, is really only doubling your labor. Yellows tend to be the fastest fading color. Titanium dioxide is reported to be the best pigment. If you are buying an expensive paint, be sure to check the can for this ingredient.
Solids are included in paints to thicken the coating. It is calculated as the percentage of the paint that finally adheres to the wall. Solids generally run more than 40 percent of the paint. Higher than 45 is considered good. Don't look for this item on the can, as it is not usually on the label. The solids and pigment are held together with binders. In an acrylic paint you will want to have all-acrylic binders for exterior paint. For interior paints this factor is not as important.
Oil and acrylic will both cover most exterior surfaces, but stucco is a special case. Be sure to use an elastomeric paint which continues to cover small cracks that can develop. Old aluminum siding can be painted. The old paint should be removed and a coat of latex primer and an additional coat or two of exterior paint can then be applied for an acceptable and durable finish.
When you go into the paint store, you will be confronted with flat, satin, and glossy paints. You should use flat for general background surfaces that are not subject to much wear and tear. Satin is better in bathrooms and kitchens where you would like to be able to clean the surface repeatedly over the years. Glossy paints accentuate a surface and bring people's attention to it. It also tends to be easier to wipe clean. Use glossy paints on cabinets, banisters, some moulding and places where little fingers are constantly smudging. Remember, though glossy paints are easier to clean, they tend to show imperfections in wood, drywall, etc.
It probably goes without saying that you should use exterior paints outside and interior paints on the inside. The fact is that exterior paints are designed to be more durable in the elements and interior paints are designed to adhere better to surfaces commonly found indoors. Recent years have brought about advancements in eco-friendly paints with zero or low VOCs. These are worth checking into especially for those who have health concerns or who frequently work with paint.