Oil vs. Water Based Paint

Written by  Harry Taylor
Last updated: July 5, 2023

There is a wide variety of paint products available on the market today. While that can be confusing, it means you have better options for your specific job.  Therefore, if you have a paint job to do, you probably have a simple question in mind: what type of paint should I use? And you want a simple answer. But of course, we cannot give you one. Both types of paint exist for a reason and are more appropriate for specific jobs than others. 

Water paint has some pretty clear advantages. It dries swiftly, and you can efficiently purify your paintbrushes with nothing but water. Meanwhile, oil takes ages to dry, and it takes a bit of effort to clean the brushes. Also, if you have ever used oil paint, you will remember that distinctive and unpleasant odour. Therefore, you may wonder why anyone uses oil-based paint. But there are good reasons to use it for specific jobs. Read on.

What to Use Indoors 

Oil-based paint tends to be more durable when used for interior jobs. They are far more resistant to scratches and scrapes. Surprisingly, even though oil-based paint does not dry as quickly, it is less prone to stains and scratches while the colour is setting. That is because once oil-based paint dries, it hardens fully and protects the walls from most forms of disfigurement. 

Meanwhile, water-based paint dries quite quickly. However, the curing process is prolonged and can extend over several weeks. During that long period, contact with the wall often shows in an obvious and displeasing manner.  That is really the main drawback of water-based paint, their tendency to erode in high-traffic areas.

For that reason, some people prefer to use water-based paint for ceilings and rooms that are used less often. In those cases, oil-based paints are utilized in high traffic areas, like corridors and living room walls.

What to Use Outdoors

However, in outdoor jobs, the durability is reversed. Surfaces expand and contract in response to the temperature. In particular, timber is sensitive to weather changes. The combination of sunlight and cold eventually breaks down the paint surface and becomes permeable. 

In addition, water-based paint is microporous. Therefore, its consistency allows trapped moisture to evaporate naturally into the atmosphere, leaving the paint unharmed.   Water-based paint is far more flexible. Therefore, it moves and breathes with temperature changes. The oil-based paint has greater rigidity, which is useful indoors but prevents it from adapting to temperature and moisture changes in the exterior. There are oil-based paints that are designed for outdoor use.

However, even those are not quite as flexible as an excellent water-based variety.  In most cases, oil-based paint is less dear than its water equivalent. Not only is the paint cheaper, but you will probably need less of it because it has a thicker consistency. 

Health and the Environment 

In both of these areas, water-based paints win by a knockout. Every popular type of paint involves chemicals that are neither friendly to the environment nor conducive to human health. However, the amounts used in oil-based varieties are far higher due to the compounds involved in the mixture.  That is one of the reasons that oil-based paint emits that unpleasant odor.

The mixture of the oil and chemicals produces a noxious brew that can also be toxic if inhaled directly. Don’t worry. It isn’t led you are smelling. However, it is a volatile organic compound (VOC). Some of the compounds are carcinogens, which means medical professionals link them to cancer. While most harmful chemicals evaporate after a few days, not all of them do.

Therefore, oil-based paint should not be used in areas that are not well ventilated. There are standards for the sale of oil-based paint in the UK, and consequently, the danger is not severe. Nonetheless, this problem counters some of the advantages oil-based paint has for interior jobs. 

The Finish Of Water & Oil Based Paints

One significant advantage that oil-based paints have over their water-based equivalents is the quality of the finish. You can gloss over oil-based paint quickly and get a shiny finish for your paint coat.  Likewise, the longer dry time allows for easier smoothing of brush marks or lack of uniformity.

Do you know how a couple of hours after you finish a paint job, you always notice that one unsightly bump? Oil-based paint usually gives you the time and means to fix them before hardening.  By way of contrast, the water-based variety dries in a flat and way and does not harden until it is too late to smooth over.

Therefore, the finish will hardly ever be as attractive and even.  However, while the finish is often less attractive, water-based paint usually does not yellow. The synthetic resins they contain are not sensitive to light-sensitive. Therefore, they maintain their colour integrity for far longer.  

oil based paint finish

Oil-based paint finish.

water based paint finish

Water-based paint finish.

Pros and Cons

To recap, each variety has advantages and disadvantages. Here is a reminder: Chemicals and the environment: advantage to water-based paint.  Expense: advantage to oil-based paint. Finish and post-paint job adjustment: advantage to oil-based paint.  Cleanliness and neatness: advantage to water-based paint.  Durability in external jobs: advantage to water-based paint. Durability in internal jobs: advantage to oil-based paint. 

The Bottom Line 

As you can see, there are several advantages to oil-based paint. It is less expensive. Easier to craft a finish and is more durable inside the house.  However, there is no way around it: in most cases, we recommend using water-based paint over oil-based. When it comes to an outdoor job, there is really no discussion to be had. 

While oil-based is better overall for internal domestic jobs, the advantages do not necessarily outweigh the unpleasantness of working with the substance, smell, and most importantly, its toxicity. 

However, there are exceptions. If you add a layer atop an existing oil-based coat, it is always better to use it again. Otherwise, it will not adhere properly. This is doubly important if the paint is applied in a high-traffic area. 

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