Lacquer and polyurethane add a smooth, glossy, and attractive coat to furniture and wood flooring. Both finishes have unique qualities that make them popular in carpentry and woodworking. Sometimes people need clarification about the identity of these finishes and which one offers good performance. This article will tell you the truth about polyurethane and lacquer. Continue reading.
What is Lacquer?
Lacquer is thinner than varnish or shellac, or polyurethane. It is a product of extracting sap from a tree, which got its name. Lacquer may have the same function as varnishes but differ in consistency.
Woodworkers prefer lacquer over other finishes due to its ease of use and quick dry property. The finished product looks glossy and smooth without compromising the wood’s durability.
Lacquer is safe to use as it does not cause damage when it seeps into the wood surface. When using it on the wood, ensure that the room has proper ventilation to dry quickly. Applying lacquer on the surface requires a low-pressure sprayer but is high in volume.
Types of Lacquer
Lacquer has three variances, and each has a unique quality. Their common denominator is they are quick-drying and resilient against extreme conditions. Here are the three variances of lacquer:
1) Water-based Lacquer
If you are avoiding obnoxious odor from lacquer, choose a water-based variance. It is friendly to your skin because it has fewer chemicals than oil-based lacquer. Water-based lacquer contains acrylic, alkyd, or vinyl acrylic polymers that help seal the wood surface, lasting five years or more. The water dissolves the microscopic plastic particles. Using this type of lacquer is advantageous over Nitrocellulose or water-based variance. It is organic as it has lesser VOCs or organic fumes and does not require an organic solvent. It is affordable and quickly dries.
2) Acrylic Lacquer
Synthetic acrylic polymers are responsible for retaining the natural wood color compared to nitrocellulose lacquers. The wood finish stays intact for years, leaving its color clear and vibrant. This lacquer is more resistant to yellowing on wood surfaces than water-based acrylic.
A CAB-acrylic lacquer offers the wood finishes resistance to scratches but is costly. It is flexible and less fragile than standard acrylic lacquer. When applying it on a wood surface, you must use a spray and add a little thinner.
3) Nitrocellulose Lacquer
The invention of nitrocellulose lacquer was in 1921 by chemist Edmund Flaherty who worked at the DuPont Chemical Company. This lacquer variance combines pulps from cotton and wood and fast-drying solvents. The sulfuric and nitric acid breaks down the cellulose from the pulp.
The primary use of nitrocellulose lacquer was for automobiles, and its usefulness for wood furniture only came later. The lacquer improves the color of the wood surface, whether it is dark or light wood furniture.
Its advantage is that it has high resistance to bruises and offers an excellent protective film to the wood surface. Since it is highly flammable, woodworkers should be extra cautious when handling it in a properly ventilated room. Avoid over-spraying it.
Advantages of Lacquer
Lacquer blends in with any previous wood coating due to its thin consistency, unlike polyurethane, which requires sanding to adhere to several layers of wood finishes.
Here are the advantages of using lacquer:
- It seals and protects the wood.
- It has many types of variances for your selection.
- It quickly dries within ten minutes.
- It looks transparent after drying.
- It is ideal for indoor furniture and home interior.
- It has high resistance to liquids.
- It is less costly.
- It is available worldwide.
- It requires light spraying that results in a smooth and glossy finish.
Disadvantages of Lacquer
Some variances of lacquer, like CAB-acrylic lacquer and Nitrocellulose, contain Volatile Organic Compounds or VOCs, making them harmful to humans and the environment. These types of lacquer can cause yellowing on the wood surface. But you can opt for water-based lacquer since it does not fade into a yellowish tinge after years of use.
Lacquer requires regular maintenance, like dusting and wiping, as the dust particles may cling to the wood surface. Water-based lacquer is not durable compared to other lacquer types, which only last five years. When exposed to moisture, it leads to an opaque finish.
Lacquer is not ideal for outdoor use as prolonged exposure to heat, moisture, and chemicals can deteriorate the wood finish. Nitrocellulose Lacquer is flammable. Lacquer finish needs three to four coats to achieve the desired finish.
What is Polyurethane?
Polyurethane is a liquid form of plastic material typically used in coating galvanized sheets and coils in steel manufacturing. Its versatility has made its way into carpentry and woodworking. Professionals hailed polyurethane as the best material for sealing and coating wood, metal, steel, and plastic.
Unlike lacquer, polyurethane has a thick consistency. It works similarly to the lacquer, providing a thick, smooth, and glossy finish. Use a spray canister to match the thickness of the lacquer if you wish.
Polyurethane can be oil or water base, and its functionality and dry time may vary. Its thick consistency makes it challenging to apply on the surface when spraying. You must combine it with a thinning agent to be able to use it with ease.
Types of Polyurethane
1) Water-based Polyurethane
This polyurethane is less harmful and does not emit an obnoxious odor. Since it has less chemical substance, it does not leave a yellowish tinge on the wood surface when it starts fading. It dries quickly compared to oil-based polyurethane.
This polyurethane type is unsuitable for kitchen tabletops as it cannot stand against heat. Apply polyurethane on furniture that does not have direct exposure to heat, such as bookcases, desks, office tables, side tables, or dressers.
A modified version of polyurethane provides resilience to heat. This polyurethane combines water and oil base solutions. It is an advanced technology and safe for kitchen tabletops. When using it, use a synthetic bristle brush, a foam roller, or a clean rag. You can apply this product to wooden flooring and walling.
2) Oil-based Polyurethane
An oil-based polyurethane can delay your work, especially if you have many projects. This wood finish is ideal if you are not working in a rush. It does not dry quickly, but it is long-lasting. The drying time could take up to 24 hours, making it less popular among woodworkers.
You can find kitchen tabletops with a polyurethane finish. The good side of this finish is that it can stand against extreme heat. If you apply polyurethane to your furniture, ensure that you do it in a well-ventilated area as it emits intolerable odor and toxic fumes.
The disadvantage of this type of polyurethane is that the wood needs proper sanding as it does not adhere to successive coats.
Advantages & Disadvantages of Polyurethane
When using polyurethane, you must weigh its benefits and disadvantages to get the best results. An oil-based polyurethane offers long-lasting benefits to the wood finish as it can withstand extreme heat. It is ideal for outdoor use.
Choose a water-based polyurethane, a combination of polyacrylic and water-based poly, if you avoid harmful odors and toxins. This type of polyurethane dries quickly.
The downside of polyurethane is that it may fade into a yellowish tinge if you apply it on lighter surfaces. You must wear a face mask and gloves if you use an oil-based polyurethane for your safety.
Another disadvantage of polyurethane is they do not dry quickly. You have to wait for 24 hours or more before applying another coating. When applying, use a natural bristle due to its thick consistency. It does not penetrate the wood.
Overall, polyurethane offers a long-lasting effect on the surface, as scratches and bruises seldom occur. It requires more time to dry and sand before applying multiple coats to seep and adhere to the wood surface.
FAQs
Which is More Costly, Lacquer or Polyurethane?
Generally, lacquer is less costly compared to polyurethane. But there are affordable brands of polyurethane, and the same goes for lacquer. You can get the best bargain if you buy them in bulk or from a wholesaler. The price relies significantly on the manufacturer, quality, and items you order.
What is the Drying Time for Lacquer and Polyurethane?
Let’s single out each type of wood finish. Lacquer dries quickly in ten minutes and is ready for the subsequent coating in thirty minutes. Using lacquer makes a good deal if you have plenty of projects, as you can apply four to five coats compared to polyurethane without waiting for the day to pass. If you prefer polyurethane, choose a water-based type, as it dries in four to six hours.
However, it is still not ready for additional coatings; you must wait 12-24 hours to dry it properly. Usually, woodworking projects require a minimum of three coats, which means water-based polyurethane coating may take three days to finish.
Summary
Choosing between lacquer and polyurethane is a personal preference. Both wood finishes have unique qualities that are not present in each one. Polyurethane can be water-based or oil-based; the latter requires more time to dry due to its thick consistency. But if you want a durable finish, professionals recommend polyurethane. Since it has toxic substances like acrylic and nitrocellulose lacquers, safety precaution is necessary as it emits poisonous chemicals and an irritating odor.