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How to Waterproof Wood (3 Quick & Easy Ways)

wet wood-pixabay

wet wood-pixabay

If you have just built a deck or patio and don’t want to cover the attractive wood with paint, you’ll want to treat the wood with waterproofing to protect it from moisture. Too much humidity can cause the wood to expand and warp, and untreated wood can invite carpenter bees and other unwanted wood burrowing insects. Ultraviolet rays in the sunlight can also damage and bleach untreated wood.

We will go over a few different methods you can use to help protect your wood and seal it from water damage. Keep reading while we discuss tung oil, varnish, water repellents, stain sealers, and more to help you make the best choice for your project.divider 4

Waterproofing Methods

We will show you several methods you can use to protect your wood from high humidity and water damage, but it’s important to remember that there’s no perfect solution. Some methods work better indoors, and some may work better with different wood grains or colors. We recommend looking over each one to see which one best resembles your circumstance.

1. Rubbed Finishes

wet wood-pixabay
Credit: rafatar, Pixabay

Rubbed finishes are a good choice for indoor woods. They seal out water and make the wood look more attractive. It makes dark woods brighter and gives lighter woods more yellow coloring. Your options for rubbed finishes are tung oil, linseed oil, and flax oil. Of these kinds, tung oil is the most expensive but longest lasting. Linseed oil is the most popular and comes in several varieties that can include ingredients to make it more resistant to ultraviolet light and mold to make it more suitable for exterior use. Exterior Performance Coatings Wet Wood Stain is a perfect example of linseed oil with additional properties, though it also stains the wood which is outside the scope of this discussion.

Traditional hand-rubbed oils tended to yellow with age, so woodworkers only used them for dark woods. However, modern varieties will not yellow, and you can use them without concern.

To Apply a Rubbed Finish:
  • Mix the solution thoroughly using a clean paint stick.
  • Apply evenly to the surface using a natural bristle paint brush.
  • Allow the oils to penetrate and soak into the surface, adding more to spots that look dry until it no longer seeps in.
  • Wipe off the excess oil.
  • Allow it to dry completely overnight.
  • Lightly sand with a finishing grade sandpaper
  • Repeat until you have the desired finish. Usually, two or three coats with linseed or flax oil, and as many as five with tung oil.

2. Sealants

Credit: Halfpoint, Shutterstock

Sealants are time tested and have excellent waterproofing characteristics. There are three kinds, including polyurethane, varnish, and lacquer.

  • Polyurethane

Polyurethane is a thick resin mixed with acrylic and various solvents. It’s available in several sheens, from a satin to a gloss and it doesn’t yellow, so it’s especially suited to light-colored woods. It’s available with an oil or latex base.

  • Varnish

Varnish also uses resins and solvent but leaves out the acrylic and replaces it with drying oils, which results in a thick, scratch-resistant finish that’s perfect for table and other heavily used surfaces. It also comes in several varieties, and you can get one that’s resistant to ultraviolet light, so you can use it outdoors. The varnish is an oil-based finish.

  • Lacquer

Lacquer is a sealant that uses resins dissolved in alcohol. You often see lacquer on furniture because it does a good job of bringing out the wood grain. It’s also available in several sheens, from satin to high gloss, and you can thin it with lacquer thinner to make it easier to work. The downside to lacquer is that it tends to yellow over time, so it’s not suitable for light-colored woods, and it has a strong odor that will require a lot of ventilation.

To Apply Stain Sealant:
  • Mix the solution thoroughly using a clean paint stick.
  • Apply evenly to the surface using a natural bristle paint brush.
  • If you are using a spray, keep your hand steady and spray evenly over the surface, watching for drips and puddles.
  • Allow it to dry completely.
  • Lightly sand with finishing-grade sandpaper.
  • Repeat until you have the desired finish.

3. Stain and Sealant

applying silicone sealant_Halfpoint_shutterstock
Credit: Halfpoint, Shutterstock

Combination stain and sealant products add pigment to the solution to make your wood surfaces more attractive.  It’s especially helpful to darken the wood so you can’t see the yellowing that comes with age in some finishes. Stain and sealant combos don’t usually leave a thick finish like varnish or lacquer and more closely resembles a rubbed finish. If you choose this type of finish for a deck or patio, you will likely need to reapply it every few years to keep protecting the wood.

To Apply Stain and Sealant:
  • Mix the solution thoroughly using a clean paint stick.
  • Work quickly and apply evenly to the surface using a natural bristle paint brush.
  • Allow it to dry completely.
  • Lightly sand with a finishing grade sandpaper
  • Repeat until you have the desired finish.

divider 6 Safety

When using any sealant product, it’s important to keep safety in mind. Make sure you have plenty of ventilation when working indoors. Keep a fan running if you can and open the windows. If you are using a spray finish, it’s best to wear a mask as well as eye protection.

One of the most important things to remember when working with any of these sealants is that they create heat as they dry, which can cause rags soaked in these liquids to catch on fire spontaneously, especially if they are crumpled up or piled on top of each other. We recommend keeping a pail of water nearby to soak the rags immediately after use. After you soak them in the water, you should hang the rags on a line to dry completely before disposing of them. Never reuse a rag.

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We recommend a sealant for most people because it’s easy to apply, and there are varieties for indoor and outdoor use. They provide a thick protective coating that looks attractive and holds up for many years. If you want a natural look for your indoor wood while protecting it from moisture, the rubbed finish should serve you fine.

We hope you have enjoyed reading and learned a little more about the various waterproofing measures you can use to protect your wood. If you think it can help others, please share these three quick and easy ways to waterproof wood on Facebook and Twitter.

Featured image credit: RosiePosie, Pixabay


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