Power washing and sanding are two preparatory processes necessary for smoothing wood surfaces before refinishing them. The one you choose depends on the condition of the surface you’re working with. Sometimes, you may need to both sand and power wash the material for the best results.
You can power wash instead of sanding a surface if the material can withstand the power washer’s pressure. Power washers save you time while preparing any surface. However, you need to choose the proper pressure setting for optimal results.
In the rest of this article, I’ll explain the instances in which pressure washing a wooden surface offers more benefits than sanding it. I’ll also discuss some facts to note about power washing any surface. So, without further ado, let’s get started!
When Should You Power Wash?
If you understand the art of pressure washing, you can power wash any surface anytime. Otherwise, you can damage even the strongest materials. Some of the instances in which you need to pressure wash include:
When the Surface Is Dirty
Painting or refinishing a dirty wood surface will only deliver subpar results. If a wood surface is dirty, you must clean it before refinishing.
A good power washer can remove mildew, mold, and other contaminants on the wood’s surface. However, you need to be careful throughout the process.
Some dirt may have dried on the wood and become very stubborn to remove. This situation may lure you into increasing the pressure of the power washer to clean the challenging stains. The increased pressure may ultimately damage the furniture you plan on refinishing.
Before you increase the pressure of your power washer, try to wash off this stubborn dirt first. These stains can often come off using a hose, soap, water, and a stiff brush.
On the other hand, you may not need sanding before painting in some cases. For example, you can paint over peeling latex paint if it’s not major and is limited to a small part of the surface. [Can You Paint Over Peeling Latex Paint?]
When the Wood Is Strong
Any wood variety you want to power wash needs enough strength to withstand the pressure and hot water. Wood may look strong but can be very weak when you try actually washing it. Some factors that determine the strength of timber include;
- Appearance. Check the furniture’s surface for deflection, rot, or other damage. After checking the front, try to examine the back if possible. Sometimes, the finish of the wood can make it look powerful when it’s weak.
- Wood type. The first way to determine if the wood is strong is its type – is the wood hard or soft? Hardwood comes from trees that lose leaves yearly, while softwood stays the same. As the name implies, hardwood is usually the more durable option.
- Age. Like with any other material, the more you use your wooden item, the weaker it becomes. Every material has an expiry date depending on how you use and maintain it. A new softwood may be stronger than an old hardwood.
- The use. The way you use a wooden item will affect its strength. Outdoor usage will make the wood item susceptible to insect and rodent attacks and unfavorable weather conditions.
When Time Is Against You
If there’s any significant advantage of using a power washer for preparing a wooden surface, it’s the time it saves. Depending on whether you’re sanding manually or with a machine, you will spend a lot of time carrying out the process. However, the power washer will do a quicker job and, in most cases, a more efficient job as well.
If you sand a wood item manually, you’ll have to put in lots of effort to get the job done. The power washer already has the pressure settings installed – all you need to do is to set it to the proper pressure level and get to work.
When You Have the Right Pressure Washer
A suitable pressure washer is vital to power washing a wooden surface. Therefore, there are some factors to consider when choosing a power washer;
- The type. Power washers come in two major categories; gas and electric washers. Some pressure washers are battery-powered, but they don’t have the strength to smoothen a wooden surface. Gas pressure washers have more power than all of their counterparts.
- The purpose. In this case, you want to use the power washer to wash and smoothen a wooden surface. However, that is not the only purpose of power washers, and buying a device solely for that purpose may make it not worth the investment. So you need to decide on how much use you can get out of the washer before making a purchase.
- The pressure rating. The pressure rating of a power washer determines the force with which the water will hit the surface. Pressure ratings range between as low as 500psi to as high as 5000psi. The power washer’s pressure rate depends on the device’s pounds per square inch(PSI) and the gallons used per minute (GPM).
- Brand. You need to trust the brand manufacturer of a pressure washer before purchasing the device. Some brands may not understand the engineering behind building a pressure washer and make mistakes. For example, pressure washer brand, Worx, recalled over 17,500 of their pressure washers because of some injury threats. It had already caused some injuries before the recall.
When You Can Use the Device
Like a gun, the pressure from a power washer can push you back; if you’re not prepared for it, you may lose balance. Power washers combine the use of hot water with extreme pressure, so you need to be extra careful.
Here are some steps to take in order to ensure your safety while using a pressure washer:
- Wear personal safety equipment. The equipment in this category should cover all parts of your body. Remember that you’re dealing with hot water, which can cause severe injuries.
- Wash at a distance. When the mouth of the power washer gun is too close to the wooden surface, it will repel with some pressure. However if you leave a distance, the pressure reduces before it hits the wooden surface. This can protect the wood from damage.
- Ensure enough distance from other people before washing. You must ensure that everyone in your home is behind you while power washing.
Things To Know About Power Washing
1. Power Washing Is Different From Pressure Washing
Pressure and power washers are not the same devices, with the latter having the additional advantage of heat. This heat increases its ability to clean tough stains and smoothen surfaces like a sanding machine.
On the other hand, pressure washers rely more on the pressure of the water to clean the surface.
It will interest you that pressure washers generally have higher pressure ratings than power washers, but the latter clean better.
However, power washers can still damage a surface if you increase the pressure or get too close.
2. Sanding Can Be As Damaging as Power Washing
Sanding a wooden surface may seem less damaging than power washing it. However, when sanding manually or with a machine, you can damage a material more than you’d think.
There are four different types of sanding machines, each with its own specifications. If you use the wrong sanding machine on a particular wooden surface, you can do more harm than good.
For instance, if you want to refinish your wooden deck, you need a finishing sander. Using a belt sander in such situations can be detrimental to the material.
Watch this video to get the perfect difference between sanding and power washing:
3. Pressure Washer Nozzles Have Different Colors and Degrees
The colors of pressure washer nozzles indicate the amount of pressure they deliver, also known as a degree. I used to think you picked colors based on preference!
Here are the four primary colors of power washer nozzles and their corresponding functions;
- Red. The red nozzle indicates that it is delivering the water at the highest PSI rating of the pressure or power washer. Also known as the 0° nozzle, this power washer is not the best for a wooden surface.
- Yellow. The yellow pressure washer nozzle is the 15° nozzle and the second most powerful. This nozzle also releases water at a high pressure level and may not be suitable for a wood surface.
- Green. The green pressure washer is the most suitable for a wooden surface. It is the 25° nozzle, delivering pressure that wood can withstand. However, please do not dwell on one location for too long, as it can lead to damage.
- White. This nozzle type is for wooden items that feature glass and other fragile components. It is the 40° nozzle and boasts a more relaxed pressure level.
The spray pattern of these nozzles is what differentiates them from each other. There are some additional nozzle colors, like black, for example, but this type is usually utilized for applying soap.
You’ll most likely need to combine sanding and pressure washing to properly prepare wooden surfaces. The process you decide to carry out first depends on the condition of the surface you’re working with.
If the material is strong, it’s better to pressure wash first, as it’s always easier to sand the wood after it gets dry.