What Is The Best Exterior Clear Coat For Wood? (Expert Advice)

Have you ever looked closely at a wooden piece and wondered why it has a shiny layer on top? The answer is the clear finish, which plays a vital role in protecting the material and upgrading its appearance in the long term.

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In today’s article, let’s dive in and learn more about this maintenance technique. What is the best exterior clear coat for wood? How do you choose a clear coat that fits your wooden projects? And are there any tips and tricks on its application? Keep reading to find out everything you need to know!

Clear Coat For Wood: Everything You Need To Know

Purposes

A clear coat is a layer of clear or semi-transparent chemical substance. It is applied on the surface of any wooden object for extra protection against external factors. Furthermore, having a clear coat brings out the material’s natural beauty, allowing the original grains and streaks to be visible. If done correctly, not only does your coated wood last for a longer time, but it also maintains a slick, visually pleasing appearance.

Types of clear coat

A clear coat is categorized into four distinct groups, namely varnish, shellac, lacquer, and polyurethane. If you have yet to know about their characteristics, check out the brief summary below.

Shellac

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Extracted naturally using a solvent (typically denatured alcohol) and secretion from female lac bugs, shellac is a wonderful choice if you want to add a bit of color to the surface. Shellac has an amber tint that blends in well with almost any kind of wood, so worry not about it tampering with the initial hue of the wood. Furthermore, once hardened and dried, shellac is 100% safe and non-toxic. Even better, it does not require re-application too often, so the cost is within the affordable range for most households.

However, it should be noted that shellac does not take well to heat. The layer will be disrupted and broken if exposed to high temperatures for a long time. Thus, it is recommended not to use shellac as a finish on kitchenware (cutting boards, kitchen table, etc.) Instead, use shellac for fine furniture to best utilize its protective nature.

When applying shellac, use a cotton rag for a brush for the best results. While it is available in both liquid and solid form, the latter would take more time and effort to dissolve.

Lacquer

Lacquer stands out compared to other finishes due to its heavy glossiness. The product comes with several toxic solvents for extra durability and damage resistance, making it less of a risk-free choice. Since lacquer has a thin texture, it is applied by spraying rather than brushing. For safety purposes, workers should wear a face mask and keep the working area well-ventilated, so the toxicity does not infiltrate the body. 

As far as the quality is concerned, lacquer can last for years before starting to show discolorations and scratches. As the coating is quite delicate, you can scrub it off with strong alcohol if you want to replace the material.

Varnish

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Varnish is an umbrella term for wooden coatings in general. But in fact, varnish itself is a highly sturdy clear coat due to a higher solid percentage. Thick in texture, varnish best acts as a base layer that covers the entire surface. It can be used either on fine objects or raw wooden boards since the petroleum-based solvent is widely versatile. If you want to achieve a plastic-like finish, simply add layers after layers until the coat becomes a hard gloss like that of lacquer. 

Another benefit of varnish is its waterproofness and UV light protection. Beach chairs, decks, or wood boats take advantage of this feature and use varnish as the main covering for a longer lifespan and better quality. 

Polyurethane

There are two subcategories of polyurethane: water-based and oil-based. 

Water-based polyurethane offers a clear coating and fits well with common household items like bookshelves, chairs, desks, etc. While it is not toxic-free, it is undoubtedly safer than varnish and lacquer. Since this substance dries out quickly, using a sprayer is more efficient than painting the wooden surface with a brush. In its original form, water-based polyurethane is susceptible to cracks and dents if exposed to chemicals and extreme heat. 

To solve this problem, some manufacturers produce an upgraded version of water-based polyurethane. By combining the durability of oil-based polyurethane and the unique charm of its water-based counterpart, this product has recently become a favorite for professional and amateur carpenters alike.

Unlike water-based polyurethane, oil-based polyurethane does not have a transparent shade. Instead, it comes with a light, yellowish tint that enriches the authentic color of the timber. Since it takes well to heat, you can safely put it on anything that might come into contact with higher temperatures. Remember, fresh polyurethane has an appalling smell, so you might want to find somewhere spacious and airy to do the work.

What Is The Best Exterior Clear Coat For Wood?

Actually, based on our experience, there is no definitively best exterior clear coat for wood. Since each type of clear coat has its pros and cons, you need to do some research and cross-reference before reaching the final decision. 

First, this requires a basic understanding of the material you are working on. Is it oak, maple, or rubberwood? What are its stiffness, strength, and hardness? Do they take well to finishes and stains? Second, examine the merits of whatever clear coat is available and see if they blend in with the timber. From there, combine what you have found together and decide on the best exterior clear coat for wood.

How To Choose A Suitable Clear Coat For Wood

When confronted with a newly made wooden object in need of a clear coat, you might want to consider the following factors.

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  • Level of clarity: Some people prefer a crystal clear coat on the wooden surface, while others want to add a splash of amber or gold-colored. Examine the shade of your items and see which one suits your taste better.
  • Ease of application: Most finishes can be applied using either a sprayer or a brush, which should be no problem for the average homeowner. However, some substances require a large working space with lots of air and wind, like lacquer or polyurethane. If you do not have a proper place to set things up, applying the coat might be difficult and ineffective.
  • Usage: Some items will suffice with just a thin layer of protection, like fine furniture with shellac. But should your projects be decks or boats, you cannot infuse a few coatings of varnish and expect them to last for life. Choose a clear coat that provides the utmost care to the wooden surface.
  • Exposure to moisture and heat: There are substances highly resistant to humidity, decay, and high temperature. Some even shield the item from UV lights. For objects placed anywhere near the direct sources of heat and dampness, make sure they are coated with the material mentioned above. But if you are looking at low-maintenance objects like bookcases or children’s toys, a moderate-performance finish will do the job.

How To Apply Clear Coat On Wood

Step 1: Find a roomy area with excellent lighting conditions. This allows you to examine your work carefully and avoid any unwanted incidents. If you intend on using foul-smelling coatings, keep the windows open and turn on the fan.

Step 2: Using a piece of medium-grit sandpaper and start scrubbing the surface of your wooden item. Smoothen out any notches or bumpy spots so that the exterior remains as sleek as possible. 

Step 3: Move on to fine-grit sandpaper and continue to level the surface. Watch out for tiny blemishes and grooves that you might have missed in the previous step. You want to optimize the surface’s condition until it is even and flawless.

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Step 4: Wipe off the dust and clean the surface using a damp piece of cloth. Do not forget to use an intact piece of drag, not anything with irregular edges or hanging threads. This makes sure that the fabric does not get stuck on the surface.

Step 5: Use a natural bristle brush and dip it into the liquid finish. Flip the object on one side and start coating it with long strokes. Keep your hand movement steady and repeat it until the entire surface is fully covered. If there is any dripping, quickly brush on it to avoid paint accumulation.

Step 6: Let the wood rest for half a day. Then, come back to brushing it with one or two more layers until you are satisfied. 

Further watching: How to finish wood in 3 easy steps. 

Conclusion

All in all, finding “what is the best exterior clear coat for wood?” is not so easy because it depends on various factors. Hopefully, after reading this article, you can apply what you have learned to any DIY project and gain impressive results!