Oil Based or Latex Paint – Which to Use for Your Home
When it comes to picking paint base, selection begins with choosing between oil-based or latex (water) based paints. For hundreds of years, people have been using oil-based paints for their impermeability and toughness. Unlike water, oil does not dry by evaporation. It dries through a process of oxidation that converts the oil into a polymer chain. This means that the layer formed will be resilient and long lasting, and will withstand the degenerative effects of water and air longer than water-based paints. There are, however, several disadvantages to oil-based paints. First of all, oil paints take longer to dry than water-based paints, have a strong odor that lingers long after the paint has been applied, and contain “volatile organic compounds” (VOCs). The paint pigment in oil paint is suspended in the solvent. VOCs are found in this solvent and are released as the paint is drying or being cured. VOCs are harmful to occupant health and the environment. Indoor air pollution has now been identified as being three times more harmful than pollution outdoors. This is mainly due to the release of VOCs by oil-based paints and other off-gassing interior VOC-containing finishes and furnishings. Government regulations regarding VOCs are becoming stricter; this may be one reason why oil-based paints are decreasing in popularity.
As opposed to oil-based paints, water-based paints (sometimes referred to as “latex paints” or “acrylic paints”) do not use solvents; the carrier for the pigment is primarily water. Latex paints have come a long way from when they were considered an inferior replacement for oil-based paints, and they’re now on the verge of dominating the market. The advantages of latex paints are many. The drying time is significantly shorter than oil-based paint, which requires up to 48 hours to dry, leaving the room unusable during this time. Latex paints also have a minimal odor and release significantly fewer VOCs during the drying process.
Because fewer or no VOCs are released, latex paint is significantly less harmful to building occupants. In addition, it requires less care to apply than oil-based paint and solvent, which are both highly flammable. Latex paint can also be thinned with water, unlike oil-based paint, which requires a special paint thinner.
Beyond oil- and water-based categorization, paints can also be classified based on their function (e.g. primers, sealers, binders, finishing paints, etc.). They can also be classified according to the type of pigment used, like zinc, lead, and titanium (each has slightly different properties).