Contemplating a paint job on the domicile? Which paint are you going to use? Well that last question depends on inside or outside. There are some choices but first McKay’s Painting would like to outlines some background material on paint.
Three Basic Ingredients in Paint
Paint is composed of carrier, base paint solids and pigment or the color. Pigments are usually solids mixed with the basic paint base, usually modern paints these are some sort of synthetic resin. Formerly oil-based paints contain linseed oil as the carrier. The carrier is the volatile material that allows all the solids to be applied to the wall, eventually evaporates leaving the solids to cover the surface. The older oil-based paints used linseed oil, latex paints don’t have any latex in them, but they do have water soluble resins, and the carrier is water.
Need to Thin Exterior Alkyd Paint
Alkyd paints or hard surface paints are resins and must be thinned and cleaned using thinner (mineral spirits) or turpentine. They do contain VOC or volatile organic compounds, but as they are used in exterior grade points this is of little concern for exposure. Not only do these out gas but dissipate almost completely in 6 months or so. VOCs from particle board can take 20 years. Alkyds dry slower but provide a harder more durable finish, making them great for outdoor wall and trim paint. Alkyd is considered an oil-based paint, and linseed oil based paints are still around. Alkyds are tougher and common. Trim takes a hammering over time, so alkyd finishes are popular for trim, walls seem to take a lot less abuse. Latex paints are a joy to work with as they are water based, making cleanup a lot easier. But latex is not as durable as alkyd paint.
Best Way to Paint Stucco, Brick & Cement Block Walls
Stucco, cement block and brick need to be pressure washed before painting. This removes peeling paint and dirt. Then apply a good primer. Latex primer for latex paint and oil-based primer for oil-based paint. Caution on brick you may not want to pressure wash as there is a chance that the washer will gouge out the relatively soft mortar in the brick seams. Same for cement block. Use TSP a non-residue cleaner and let dry forty-eight hours before painting. For stucco we have elastomeric paints, these coats are 5-10 times thicker than normal paint and provide a near perfect water-proof seal if properly applied. Stucco cracks can be filled with a latex or other outside grade caulk. Stucco demands the highest-grade latex or elastomeric paint possible. It should be labeled as designed for just stucco.
Mold on Walls Must Be Treated Before Painting
Mold can be cleaned up using a 50-50 mixture of water and bleach. The big caveat with mold and mildew on stucco is unless the source of moisture is cut of it will recur. Some paints contain mildewcide to control growth. Molds contain allergens, causing allergic reactions. Some worse than others and are considered ‘toxic’ and cause memory loss, fatigue, seizures and brain damage. Extreme, and rare, but must be considered. Children have more frequent asthma attacks if exposed to molds and suffer from more bouts of wheezing and upper respiratory infections. Some mold, however, is present in every home to some degree. Mold feeds on organic materials and thrives wherever moisture is present. Mold is unavoidable in the home but can be controlled. Where does mold hide, HVAC duct work, around water leakage, bathrooms, drywall in humid conditions, under the fridge and around windows. Mold must be dealt with before painting. Alkyd paints are chemical based while the acrylic resins in latex paint are water based.
Paint Sheen Standards
Sheen is based on reflectivity. Flat, satin, semi-gloss and gloss are a measure of how much light they reflect. Gloss has the highest reflectivity, but does a poor job of hiding imperfections, but is more abrasive resistant and washes easier than flat, but flat paints help smooth out and hide imperfections. For exterior use Satin finish is the best with semi-gloss or gloss on trim. Indoors flat reigns supreme but can not handle high traffic areas accompanied by regular washing, best to use some other sheen in high traffic areas.