DIVERSIFIED COATINGS, INC.

1. Question: Generally speaking, when do I need to use a primer?

Answer: A rule of thumb is to prime a surface that has not been painted before. Be sure to choose a primer recommended for the particular kind of surface you are painting, such as wall board (sheetrock), staining wood (mahogany, cedar, redwood), steel, etc. Most types of primers are available in both latex and oil based formulas. Sound repaint surfaces will benefit from priming, as well, resulting in maximum adhesion and uniformity of appearance from the finish coat.

2. Question: What are the reasons for priming?

Answer: Using an appropriate primer provides these benefits:

maximum adhesion of the finish coat
blocking of staining material from the surface being painted
uniformity of appearance of finish coat, including gloss or sheen development, and hiding

3. Question: When Should I Use Oil-Based Paint, and When Latex Based?

Answer: For nearly all coating types, quality latex alternatives are available. Quality latex products offer superior resistance to yellowing, long term resistance to embrittlement, maximum color retention and resistance to chalking, and mildew resistance. Areas where oil-based might be chosen, rather than latex, are:

for wood varnish where a "warmer" appearance is wanted;
for enamels when the very highest glossiness is desired;
for semitransparent stains or wiping stains when lack of lap marks is essential
where the coating is going over a chalky surface
when a primer with the very best stain blocking capability is required

4. Question: When do I use natural a bristle brush, and a synthetic bristle brush?

Answer: Natural bristle brushes should be used for oil-based paints and stains, and not for water-based or latex products. Use a polyester or Nylon bristle brush for latex products. Some polyester brushes are made for both latex and oil-based products.

5. Question: What are some main things to do when painting exterior wood?

Answer: Exterior bare wood should be primed before painting. Try to prime and paint the wood while it is new and has not weathered; any wood that has weathered more than a few weeks should be thoroughly sanded before being primed.

6. Question: How can I figure out how much paint to buy?

Answer: For a smooth surface, most paints will apply at about 350 or 400 square feet per gallon. You need to measure the surface area of the job. Divide the area into rectangular areas and multiply the width times the height to get the area of each rectangle, then add all the areas together. Divide the total area by 350 to see how many gallons will be needed for each coat. If the surface is rough or porous, the paint will cover at a lower spread rate, such as 175 or 200 or 250 square feet per gallon.

7. Question: When would I choose a flat paint or a satin paint?

Answer: Flat paints are good for a muted, dull finish where dirt is not likely to get onto the paint. (Flat paints can absorb dirt, and be more difficult to clean.) This could be for living room or bedroom walls, or a ceiling. Satin paints are better for walls of "high traffic" areas like hallways, playrooms and kitchens; but a satin finish will show up unevenness of wall area more than will a flat finish.

8. Question: What basic safety equipment should I have when painting?

Answer: In general, some things you will have need of are:

goggles to protect the eyes when scraping, sanding, painting
a dust mask for scraping, sanding
an appropriate respirator to protect breathing when using any solvents indoors, like paint thinner, oil-based paint, primer or stain, paint remover, brush cleaner, etc.; or when spray painting
chemical resistant gloves when using solvents like paint remover, paint thinner, etc.; and leather or cloth gloves for scraping, sanding, etc.
note: do not scrape, sand, heat-gun or otherwise attempt to remove paint if there may be lead in it; rather, contact the EPA at the lead information number for guidance: 1-800-424-LEAD

9. Question: What do I have to do to paint metal?

Answer: Remove any loose paint, using a scraper, wire brush, sand paper, etc., except with galvanized iron (do not scratch off the zinc coating). Use a stiff wire brush to remove all rust (on iron, steel) or white oxide (on aluminum). Then apply a metal primer. Use a quality acrylic latex flat, satin, semi-gloss or gloss paint. Alternatively, a directtometal paint may be used without a primer.

10. Question: How do I get the best appearance when applying latex semi-gloss or gloss paint to interior trim?

Answer: Follow these points:

clean and rinse the trim; dull glossy areas with fine sandpaper
apply a latex or alcohol-based or oil-based stain blocking primer
use a top-of-the-line paint
if applying by brush, choose a top quality polyester brush; pre-dampen the brush before using, and remove all excess water
apply the paint in heavy coats; do not brush the paint excessively; do not thin the paint unless necessary

11. Question: What are the main things I should take into account when painting masonry, like stucco or brick?

Answer: In preparing the surface, first look for any "efflorescence", which is an accumulation of white powder or salt-like material. This is brought to the surface by moisture coming from above or behind the masonry, to seek out and eliminate the source of moisture. Remove the efflorescence along with all loose sand, dirt, old flaking paint, etc., with a stiff wire brush. Masonry less than a year old, and very porous masonry and masonry with signs of efflorescence should have a sealer or primer applied, before painting.

12. Question: What are the maximum and minimum temperatures at which I can apply a latex paint?

Answer:

Low temperature: the paint will have a minimum recommended application temperature on the label (typically 50 degrees F) .)... this includes temperature of the surface being painted; and application should not be done if the temperature is predicted to be below the recommended minimum in the next 36 hours.

High temperature: do not apply the paint under conditions that will make it dry very quickly; this includes painting in direct sunshine, painting when it is dry and breezyÉ and when the temperature is very high: it is best to avoid painting in temperatures over 95 degrees F

13. Question: What do I do about mold or mildew on an exterior surface I want to paint?

Answer: As a part of surface preparation, all mold and mildew should be removed. We recommend using
X-MOLD!

14. Question: Can you paint over an oil-based paint with latex paint? Or use oil-based over latex?

Answer: Generally speaking, with proper surface preparation, for exterior use you can apply quality latex paints over oil-based, but not the reverse. However, if you have many layers of oil based paint, stick to using oil on oil. For interior use, generally you can use one over the other. Some manufacturers of latex products will recommend a primer when going over oil-based paint.

15. Question: What should be done when painting new wallboard (sheetrock, gypsum board)?

Answer: After all joints have been sanded perfectly smooth, this surface should be first coated with a PVA wallboard primer. If there is sign of stain bleed-through, then switch to a latex stain-blocking primer. Then apply an interior flat, eggshell or satin wall paint. Priming is essential for obtaining a smooth, uniform appearance.

16. Question: Can old, weathered aluminum siding be successfully painted?

Answer: Yes. Take into account these points:

the old finish is likely to be very chalky, so clean it thoroughly; power washing is effective for this
apply a top quality exterior acrylic latex flat or satin paint
spray application will provide the smoothest appearance, though brush or roller can be used
a flat finish will make dents and bends in the siding less noticeable than a satin finish

17. Question: What should be done to paint interior wood paneling?

Answer: First, thoroughly clean the paneling with warm water and detergent; rinse thoroughly. Then apply a high adhesion stain blocking interior or interior/exterior latex primer. After the primer has dried thoroughly, apply a quality interior latex flat, eggshell or satin wall paint.

18. Question: What are some things to know about choosing paint rollers?

Answer: Generally, higher quality roller covers are worth the added cost, vs. economy rollers, because the apply the paint more heavily and smoothly, which results in better hiding, appearance and durability. Use natural lambs wool and mohair for oil-based paints, primers, stains and varnishes; and use synthetic nap roller covers for water based coatings. Short nap rollers (1/8" nap) are for smooth surfaces like finished paneling, painted doors, etc.; medium length (3/8" nap) are for surfaces like flat paint, bare wood, etc.; and long nap rollers (more than 1/2") are best for rough surfaces like stucco, brick, etc.

19. Question: What are elastomeric coatings?

Answer: Elastomeric wall coatings are designed for exterior masonry surfaces like concrete, stucco and concrete block. They are generally acrylic latex masonry paints designed to be applied in very thick films (about 10 times as thick as regular paints); they are tough and flexible, and stretch as cracks underneath open and close, thus bridging the cracks and keeping wind driven rain out while maintaining a nice appearance. These coatings are called EWCs for short. They can be tinted to a light color. The EWC should be applied after cracks more than 1/16" are caulked with a quality acrylic or siliconized (not SILICONE) caulk. (If the stucco is particularly porous, a masonry primer or paintable sealer should be applied first.) Applications of the EWC is usually at about 50 60 square feet/gallon, and two coats should be applied.

20. Question: What is the difference between a paint and a stain?

Answer: The objective in applying a stain is usually to change the color of the surface (typically bare wood or concrete) without hiding the texture of the material. Some stains, called semitransparent stains, also let the grain pattern of the wood be seen, as well. With paint, we create a new appearance, that is, the surface takes on the appearance of the paint (which may be flat, satiny, or glossy; smooth or textured), and the texture and grain of the surface is obscured. Stains are typically thinner (of lower viscosity) than are paints; and the level of prime pigment (that provides color and hiding) will vary with different types of stains. Interior stains are usually top coated with a clear coating (such as polyurethane varnish), whereas exterior stains often are left uncoated. In exterior applications, a quality paint job will generally last longer than will staining.

For More Information on Paints and Painting visit the Paint Quality Institute web site or ask our paint experts.