Last updated on April 10, 2022 9:14 pm by the writer.
Are polyurethane and lacquer the same thing? The answer is no. Lacquer and Polyurethane are two of the most common and popular choices for wood finishes. They both provide a smooth, glossy coat and the lack of visible differences often causes one to be confused for the other.
Identities aside, what we will be looking at today are some key distinctions between the two in order to determine which would be the better finish for you to choose.
Why is coating needed?
Finishing wood primarily grants you two things: added durability and aesthetics.
Multiple coats on wood give it an additional layer of protection, sealing it from water and excess moisture, as well protect better from scratches and dirt or finishing the wood after removing wood paint, repainting, or sanding after getting stained.
Additional coats and finishes also improve aesthetics by enhancing and highlighting a wood’s natural beauty more.
Let’s start comparing polyurethane vs lacquer.
What is lacquer?
“Lacquer” is a term used to describe finishes that form hard and usually very glossy coats upon drying.
Lacquer is the preferred finish of those who aim for more protection due to its superior durability, resistance, and ability to easily latch on too almost any surface.
Types of lacquer
These types of Lacquers are synthesized from the resin of wax and Lacquer trees.
Urushiol-based Lacquers are more famous in Asia since it’s where they’re heavily sourced.
These cure through oxidation and polymerization rather than through the evaporation of chemical solve
This type of Lacquer is the most dominant finish for musical instruments.
It’s a visually interesting finish as it can help add to the beauty of wood because of the fact that it tends to form a reddish-amber tint as it ages.
It’s not for all wood, especially on lighter ones that tend to yellow with age. It’s prone to “crazing” and is probably the least durable out of all the types.
Acrylic Lacquers contain acrylic polymers that combat wood discoloration associated with aging. This makes this kind of Lacquer really popular with craftsmen and commercial manufacturers.
Acrylic Lacquers do well even with lighter woods and are more damage and water-resistant than nitrocellulose ones.
Waterborne Lacquers are probably the safest among the Lacquer types since they have the least amount of hazardous chemicals in their composition.
Consider these the organic Lacquers as they’re the most environment-friendly option. However, they aren’t the toughest and are quite prone to wear and tear.
NOTE: Please be aware that Lacquer contains toxins and is hazardous if ingested, persists on the skin for too long, or if you inhale it as it releases harmful fumes.
What is polyurethane?
Polyurethane is a very common polymer used in various industries.
It’s used as a term that describes a class of polymers more than a distinct compound.
As a finish, Polyurethane is basically liquid-plastic – once it dries, it forms a clear and glossy protective layer.
Types of polyurethane
Similar to most water-based finishes, waterborne Polyurethane is safer and more sustainable.
One strong point this type of Polyurethane finish has is that it looks identical to traditional finishes, but dries at twice the rate.
It’s also waterproof and provides adequate protection against wear.
Known as the traditional finish. Solvent-based Polyurethane works pretty much in the same way as any other solvent-based finish.
It’s ideal for general use and has a rather high life expectancy.
Here’s a more detailed comparison of water and oil-based stain.
Difference in chemical composition
Shellac is a resin secreted by the female lac bug and is processed from its solid, amber-like form into liquid shellac which is later mixed with various synthetic polymers and organic solvents.
In the case of Urushiol-based lacquers, the resin is instead harvested from Asian Lacquer trees which contain traces of the same active toxin found in Poison Oak and Poison Ivy.
Going into the exact chemical composition of Polyurethane will transform this guide into a research paper, so will go with the basics of how Polyurethane is formed.
Polyurethanes are formed when a type of alcohol called polyol reacts with either a diisocyanate or a polymeric isocyanate, which are basically chemical building blocks, in the presence of a catalyst.
Polyurethane is best recognized as foam, but using different catalysts and other materials during the reaction process produces the liquid Polyurethane that’s used as a finish.
Differences in color sheen
Sheen refers to the level of shine or luster of a surface.
Lacquer has the broader sheen spectrum of the two.
Since it’s thinner and already starts as a clear, liquid base, Lacquer offers more options in selecting preferred levels of luster.
It can start out at ultra-matte (less than 10% sheen) and progress in increments all the way up to ultra-glossy (90+% sheen).
Talking about a lacquer vs polyurethane finish, polyurethane is not as clear as Lacquer. However, it is more durable as a finish and can be applied over oil-based coating as a secondary or even tertiary layer.
Polyurethane finishes do have slightly higher initial sheen options at satin levels (30-50% sheen).
They can still provide exquisite shine with their semi and high-gloss options (60-90% sheen).
- Quick-drying, ideal for time-sensitive or rush projects.
- A thin layer, best for highlighting the wood grain.
- For more mature households since it’s generally mildly toxic.
- For projects that demand consistency and symmetry. Lacquer can be applied using a pressure spray.
- For projects meant to undergo intermittent repair or restoration.
- Slow drying, better for freeflow and DIY projects.
- The thick-layer finish provides added durability and viability for applications that will have heavy usage..
- For more frequented elements such as flooring and furniture frames (these tend to experience wear and stress on a regular basis).
- If you need a safer option for a finish (non-toxic).
- For projects that require multiple coats and prioritize protection.
Methods of application
Here are the difference between lacquer and polyurethane when it comes to the application methods.
Due to its multiple types, Lacquer can be applied either with a brush or by using a pressure sprayer.
When it comes to spray lacquer vs polyurethane, first consider that Lacquer’s generally thin characteristic, it’s actually recommended to use a sprayer for faster and more consistent application.
Regardless of the type, Polyurethane always finishes as a thick coat. Because it’s more viscous, the most efficient way to apply a Polyurethane finish is with a brush, preferably a thick-bristle one.
Which is easier to apply?
Polyurethane is easier to apply because of the fact that not everyone has the means to acquire and properly use a pressure spray.
Lacquer is known for its quick-drying and curing time. If you don’t mind the unpleasant fumes, Lacquer dries as fast as a few minutes after application. For best results, it’d still be best to allow it to cure for about 8hrs at least.
Polyurethane is much safer and much more odorless, however, its thickness and composition require a minimum of 24 hours dry.
Water-based Polyurethane dries faster (1-2hrs). You can also increase heat with the use of a hairdryer or use thinner to quicken the drying process.
Which dries faster?
Lacquer. Acrylic Lacquer dries faster than even water-based Polyurethane.
Lacquer has a pretty good tolerance towards climate change. Because Lacquer is compatible with various solvents, it’s possible to then add said solvents to the finish to compensate for changes in weather.
Polyurethane can be used outdoors, but it has to be the variant that’s intended for exterior applications as those are the ones with the necessary additives that protect against UV damage.
Which can stand different types of weather?
Lacquer is generally better for outdoor use.
Number of coats and in-between coating
For non-specific applications, even a single coat of lacquer would do.
Lacquer does relatively well with just 2 or 3 coats since it penetrates the wood, sealing it from the inside and out.
Multiple coatings can be applied easily given how fast this finish dries.
For good protection, a minimum of 2 coats is needed.
Anywhere between 2-4 coats of Polyurethane will do, depending on how durable you need projects to be.
However, this will take quite some time as you need the previous layer to dry and cure first before proceeding to add another.
How many coats?
Lacquer if you need multiple coats and Polyurethane if you’re content with just a single-coat finish.
Durability and permanence
What’s more durable between polyurethane and lacquer? Let’s see.
Lacquer is quite durable and can last for years even without too much hands-on care.
One distinct and praised advantage of Lacquer is its ability to stay clear and not yellow over time. It’s also easier to repair.
Great care and precision must be taken during application as conditions unaccounted for or moving the sprayer too quickly can result in defects such as blush, fish-eye, and orange peel.
Especially oil-based Polyurethane, this finish is generally more durable and resilient as it results in a thick, hard, scratch-resistant surface.
Though not as flexible to weather changes, the variant with the right additives can last for years even under the harsh conditions of the outside.
It has hard to repair Polyurethane-surface but it does discolor over time.
Which lasts longer?
Polyurethane offers superior protection and lasts a bit longer. Lacquer is durable too but is more prone to damage and cracking if mishandled.
Alternatives for lacquer and polyurethane
Regardless of the project, finishing woods like Acacia or Teak will always yield these two results: protection and appearance.
Whatever finish you use, you will always get these 2 properties.
Some may look better than others, while others still might offer better protection.
Shellac is basically a purer version of Lacquer, offering nearly the same benefits while looking more natural.
Varnish is kind of like an upgraded version of Polyurethane, albeit more durable and a little trickier to smoothly apply.
When comparing two things that basically have the same function, it’s more subjective than objective; really.
By subjective, we mean that deciding between Lacquer and Polyurethane, with knowledge on their pros and cons, mainly boils down to which you deem is better suited for your project/s as well as your financial capabilities.
So, what’s the difference between lacquer and polyurethane? Lacquer is more affordable and offers decent benefits for its price. And Polyurethane is more beautiful and offers better protection, but at the cost of application time and discoloration over time. You start the project, one of these will surely finish it.
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