Is That Second Coat of Paint Really Necessary?

Intro

One of the frequent questions we hear is, “Do I really need for a second coat of paint?” The question applies to both interior and exterior painting.  We set out to investigate the answer from both a technical and cosmetic perspective.

Paint Cans Say Two

Almost all paint labels specify two coats of finish over a properly prepared surface.  If not on the can itself, these instructions are on the MSDS which can be viewed at the paint company’s web site.  There are a few “one coat” paints on the market, but there are some inherent drawbacks to these products and we will address those issues as well.  To obtain the benefits of exterior paint warranties, almost all require two coats.

One Coat of Paint Over Identical Colors

Consumers are dealing with the reality of today’s economic climate and looking for ways to paint using lower cost alternatives. Conceptually, a one coat paint job should make sense.  The idea based on using less labor and less paint.  If you are painting over identical colors (and PS there are even shade variations in whites), you might be able to get by with one coat.  This is rarely an option.   Depending on low long ago the surface was painted, the colors on the wall are likely faded (even interior paints fade).

“One Coat” Coverage Paints

These so-called “one coat” coverage paints create a problem for professional painters and even more for DIY consumers. These products have additional polymer components that are supposed to be self-priming.  Funny, all the labels we read include a statement that bare and suspect surfaces should be primed before application.  The bigger issues here are clean up, sheen variations and lap marks.
There is also a concern for repaints down the road.

While these products are technically in the latex family (as opposed to alkyd or oil based).  They are supposed to be water soluble.  Again, all the labels examined suggested you will likely need mineral spirits to clean up tools and any paint you get on yourself.  Thought mineral spirits were only required to clean up oil based paints?

Lap marks appear as color and sheen differences.  These occur when wet and dry layers overlap during painting.  One coat products tend to dry faster than traditional latex paints.  Keeping a wet edge is nearly impossible even for the best of professional painters much less the typical DIY homeowner.  Even flat sheen paints in these products will show sheen and lap marks on interior walls.

The same components that make these products work can cause issues on subsequent repaints.  Applications using traditional latex coatings may be subject to a condition we call “fish eyes.”  This symptom is very common when latex is painted over oil based paints.  The extra polymers in these products will cause the water in latex to separate.  (think how a drop of oil reacts in a glass of water).  You may need to prime the entire surface with a high quality oil based primer and then apply the latex.  So much for the one coat savings idea!  This process is messy and will cost you more than if you had painted two coats the first time.

While it may be tempting to use these short-cut products, the results can be less than favorable.   We recommend against using them on most applications.

Meanwhile, Back to Two Coats

The basic answer here is yes!  In almost all applications, you should apply two coats of finish paint.  Exterior masonry, new drywall or bare wood surfaces should be cleaned, prepped and either sealed or primed first.  This creates the canvas for the finish coating.  Interior walls and trim should be tested for alkyd paint (see fish eyes above as well).  Surfaces that test positive should be primed before painting.

Never skimp on paint quality.  Use only high quality paints and sheens designed for the job.  Keep a wet edge at all times.  Work efficiently to cover all surfaces with manufacturer’s millage (thickness).   Most consumers don’t keep enough paint on brushes or rollers.  This will make lap marks worse.  Drying into the surface before coverage is your enemy.  You have to keep the surface wet until the job is done.  The first coat can be viewed as your layer of protection.  The second coat is your layer of beauty.  All paints fade over time.  Two coats assure your colors will stay true for a longer period of time.

The Bottom Line

TV shows and retailers love to make you think painting is so easy.  Anyone can do it!  (Surprised they don’t have those two hairy guys to appear in their commercials.) DIY plays well to budget conscious consumers looking for a bargain.  Truth is… there’s a lot more than meets eye here.  If you are going to paint, do it right!  The paint itself is the cheapest part.  Don’t buy cheap products and don’t be lured by tag lines promising short cuts.  This is your home or business.  You want it to be protected.  You want it to look great.  It’s hard work and it’s takes artistic talent.

Hire a Professional

Hiring a professional may be a better solution.  There are challenges here as well.  Virtually anyone with a truck, ladder and a brush can call themselves a painter. Careful! Some of these individuals know less than you do about paint applications.  Make sure your painting contractor has the knowledge required and the talent to get the job done right.  Your painting contractor should provide detailed and informed alternatives for your project.  They must be licensed, insured and bonded.  They should be well known for their integrity and quality.  Make them show you pictures of their work. These pictures speak a thousand words.  Check with your local chamber of commerce and see if they know the company.  Reputable firms will be active members of the business and local community.