Water-based vs oil-based paints
There’s confusion surrounding what is better – water-based paints or oil-based paints? Oil-based paints used to dominate the market. Water-based paints are a newer innovation and started out with a reputation for being inferior to oil-based paint. Yet as time has gone by, water-based paints have become much more popular than oil-based paints. It all comes down to the type of solvent used in the paint. The solvent is the liquid component of the paint that evaporates as it dries. But, what is the difference between the two types of paint?
03 July 2019
What is an oil-based paint?
Oil-based paints are sometimes referred to as enamel paints. The solvent used in this type of paint is made with either alkyd (synthetic) or linseed (natural) oils. Alkyd paint is the most common option because it’s less expensive and tougher. This paint is typically made with mineral turpentine, which is used to modify the viscosity (thickness) of the paint.
What is a water-based paint?
Water-based paints are sometimes known as latex or acrylic paints. The solvent used in this type of paint is almost all water. Water-based paints now heavily dominate the market, accounting for nearly 80% of all paints sold today.
Application of an oil-based paints is a much slower process than its water-based counterpart. The paint feels a lot stickier and thicker so it takes a lot more time to apply. It also takes longer to dry. It’s not uncommon to wait 24 hours for oil-based paint to completely dry so you might have to wait a day before applying a second coat. They do have very good adhesion and are more suited to repainting surfaces with heavy chalking. They set harder a lot faster - usually within a couple of days. Weather conditions have less of an impact on applications. However, oil paints repel water which means the surface must be completely dry before application.
These paints are a lot easier to work with and are much quicker to apply. They dry promptly, normally taking only between one to six hours. Yes, that right! You can easily get two coats done in a day. However, it take longer to fully cure than oil-based paint so you might have to be careful for a few weeks until the paint completely hardens. The drying time can be affected by the climate. High humidity can prevent water-based paints from drying fully. Lower and higher temperatures can be a pain for the application process. If they dry too quickly or too slowly, the finished result as well as the long-term performance of the paint can be compromised. However unlike oil-based paint we can allow for a small amount of moisture on the surface before application and it won’t affect the ability to create an adhesive bond to the surface.
Oil-based paint has a reputation for being a lot more durable. The paint dries hard, providing excellent resistance to wear and tear. This resistance makes it perfect for painting trim work and baseboards, as these area tends to cop a lot more abuse than the walls with accidental knocks, dings and scrapes. However, overtime oil-based paint tends to experience issues. They are more prone to yellowing. White gloss is a top offender for this. It can also oxidise, resulting in the paint becoming brittle with chipping and cracking problems. As this paint is less flexible once it is dry, it finds it hard to expand and contract in different weather conditions. It’s also a lot more sensitive to light, as the UV light breaks the paint down and can give it a chalky surface.
Water-based paints have a reputation for not being as durable as oil-based paints but with more recent advancements in paint this isn’t as correct anymore. These paints perform well in that they are not as sensitive to light and UV rays so they can stay whiter for longer. They are also a lot more flexible and allow for movement, making them less likely to crack.
Oil-based paints excel when it comes to sheen. Because they take longer to dry the paint can be worked for longer, smoothing out any brush marks for a better finish. The shine really makes exteriors and interior trims stand out and the windows don't stick to the trims when they are opened and closed. However the finish, although harder wearing, doesn’t last as long as water-based paints and there’s a tendency to have a restricted range of colour options.
These tend to not have a great sheen although they are improving. They tend to dry slightly flat. Thank to the slow curing time, they can be difficult to sand down to get that smooth finish. However the sheen level will last over a longer period of time. They retain sheen levels and colour over longer periods than oil-based paints. There is usually a full range of colour options for this type of paint.
It’s a lot harder to clean up after using oil-based paints. Most require mineral spirits, turpentine or specialty thinner to be used for cleaning. The brushes will need to be cleaned in this fashion as well.
This paint is a lot simpler and easier to clean up. Brushes and painting accessories can be cleaned up with some soap and water instead of harmful chemicals.
An easy way to check if your paint is oil-based or water-based is to read the label’s instruction on how you clean it up. If it says you can clean it up with water, it’s water-based
Oil-based paint has a strong chemical odour due to its high amount of volatile organic compounds (VOC). VOCs are released as the solvent evaporates into air as part of the drying process. This causes that strong new paint smell. These fumes can cause headaches, nausea, dizziness and fatigue. It’s important to ensure air circulation within the room you are painting. Oil-based paints are also flammable.
Water-based paints are made up primarily of water, so they release less VOCs as they dry. They have less odour and their smell isn’t as strong. It’s a lot better for the environment and your health than oil-based paint. However it’s still important to have air circulating within the room.
So which one is better?
Overall, it’s up to you and depends on your needs and wants. There are advantages and disadvantages with both types of paint. Water-based paints perform better exteriorly, they are continuously improving and they’re much better for the environment. But some would say you can’t beat the old-school shine from an oil-based paint. Whatever type of paint you decide to use, make sure you realistically see how the colour will look on your walls first with one of our digital renders.