What is conversion varnish?

Conversion varnish (CV) is a lacquer containing a hardening agent. It’s commonly used on cabinets and woodwork for its protective coating and clear finish.  

Because it’s both durable and visually appealing, conversion varnish is a great choice for refinishing your kitchen cabinets or drawer fronts. But before you commit, know that CV comes with a few caveats.

In this guide, we tell you everything you need to know about what conversion varnish is, from its pros and cons to its application process and how to maintain it. By the end, you’ll be able to decide whether CV is right for your project.

What is conversion varnish, and how is it different from traditional lacquers?

When looking for the right finish, many woodworkers and DIYers will pick one of two options: varnish or lacquer. Varnish is oil- or alkyd-based and dries through solvent evaporation. Lacquer is solvent-based and also dries through solvent evaporation — though much faster than varnish.

But conversion varnish is completely different. With a two-component system, it’s known for its extraordinary resistance to chemicals, wear, and moisture. 

With that in mind, the results of lacquer and CV may look similar, but they are entirely different materials. Here are some of their key differences:

Composition

• Conversion varnish is a chemical-cured, fast-drying finish consisting of two parts: a resin and a hardening agent. You add the latter right before application. It has an acidic component that catalyzes the chemical curing process.
• Lacquer is a single-component mixture consisting of a pre-catalyzed, nitrocellulose finish that’s air-cured. Because it’s pre-catalyzed, it’s ready to use without mixing in any hardeners.

Curing process

• • When the components in CV mix, the hardener catalyzes a chemical reaction called cross-linking. After applying the varnish, you use heat to accelerate and complete the curing process. This process creates the hardest finish on the market. It’s a delicate process because the mixture must contain the correct ratio of the two chemicals to harden properly.
  • Lacquer cures through the evaporation of solvents, with the liquid mixture turning into a solid film. While it dries quickly and is a straightforward, DIY-friendly process, it doesn’t achieve the same level of hardness as CV.

Application

• You can apply CV in thicker coats than lacquer, providing a substantial protective layer. This thickness contributes to the enhanced durability of the finish. You can paint conversion varnish on with a brush or use a specialized sprayer.
• Due to its quick dry time, lacquer requires only thin coats. But, with a low solid content (12% to 18% solids per volume), you will have to reapply these coats many times for proper build and solid film density.

Appearance

• CV dries to a clear finish, providing a glossy or satin appearance. It enhances the natural beauty of the wood or painted surface without significantly changing the color. This clarity makes it a popular choice for high-end woodworking projects.
• Lacquer can be clear or pigmented, offering a range of finish options. While clear lacquer allows the natural wood color to show through, it also comes in various colors if you want to make a bolder statement without covering the wood’s grain patterns.

The key difference you should be aware of is that conversion varnish is significantly more durable. Lacquer is susceptible to scratches and less flexible than CV — and most varnishes — which makes it more prone to cracking. 

Conversion varnish advantages

CV offers numerous benefits in cabinet renovation. It distinguishes itself from other finishes with its inimitable durability, anti-yellowing properties, and easy-to-clean (and repair) formulation. 

But what is conversion varnish’s biggest pro for kitchens? The answer is its ability to give you long-lasting cabinets without sacrificing aesthetics. Unlike lacquer, conversion varnish forms a tough and flexible finish that’s ideally suited for busy and humid environments. This marries with its luxe effect to create a kitchen that will look and function great for years to come. 

High durability

CV has a harder and more robust finish than any other lacquer or varnish. For example, it has twice the dry film thickness as lacquer, making it less likely to scratch over time.

Conversion varnish’s durability is ideal for high-traffic kitchens, allowing you to strike the perfect balance between style and protection.

More longevity

This varnish not only withstands a lot of abuse. It also stands the test of time. By forming a strong bond with the wood substrate, it offers excellent adhesion properties to ensure a long-lasting finish.

CV is also formulated to resist yellowing. This helps it maintain clarity and prevent the wood from taking on an undesirable tint, which is quite common with traditional varnishes and lacquers.

Flexible and elastic

CV is more elastic than lacquer due to its unique chemical curing process. The cross-linking of molecules creates a more resilient finish compared with the brittle nature of lacquer. This increased flexibility is crucial for the finish’s ability to resist the natural expansion and retraction of wood.

As a result, its elasticity reduces the chance of cracks at the joints and minimizes the risk of cracking or peeling over time, making it an ideal choice for kitchen cabinets.

Enhances kitchen aesthetics

Its high-quality appearance is why CV is the preferred choice for premium woodworking projects. Achieving clear, glossy, or satin finishes, you can bring this same level of professionalism to the heart of your home by using CV.

This varnish is particularly complementary to traditional, transitional, and rustic kitchens. Allowing the richness of your cabinets’ wood grains to take center stage adds a touch of refinement without erasing any character. You can even use it to top-coat painted cabinet doors, giving them extra luster and protection from chipping.

Requires fewer coats

CV has a higher solid content (about 40-60% solids by volume) than lacquer. This means it doesn’t take as many coats to get good coverage and an appropriate film build.

The main advantage of this lies in efficiency gains during the finishing process. CV reduces time and effort while minimizing uneven layers.

Easy to clean

Conversion varnish applies smoothly and has a durable finish, making it easy to clean. Its non-porous surface also helps with this, preventing contaminants from penetrating the finish. 

The durability and ease of cleaning make CV a practical choice for surfaces that require frequent maintenance, such as kitchen cabinets, which often get food stuck on them.

Conversion varnish disadvantages

From its complexity of application to its cost and curing time, CV comes with a few drawbacks. Let’s cover some of conversion varnish’s disadvantages. That way, you have all the information you need to make the right call for your project.  

Complex application

The biggest problem you’ll encounter with CV will be its complex application. It requires greater skill in spraying and careful mixing of the two components to ensure the correct ratio.

Improper mixing or application leads to poor adhesion, color shifting, and an uneven or cracked finish. Unless you’re a seasoned DIYer with experience using CV, it’s best to hire a professional. 

Application environment

During application, CV is sensitive to environmental conditions like temperature and humidity. Inconsistent conditions during application affect the curing process and final appearance.

You will need to ensure your environment is at a consistent temperature during application and in the upper 60s for the first two days after application.

More expensive than other finishes

CV is more expensive than other finishes. Most lacquers cost around $25 per gallon, whereas CV is usually $60 to $80 per gallon.

You will also need to pay for application equipment, like spray systems, as well as labor costs if using a professional. These extra costs could take you over your budget.

Curing time

While conversion varnish will reach almost full hardness fairly quickly, it has a fairly long cure time. For example, within the first 48 hours, your CV may cure to 60% to 85%. But after 10 days, it may still only be 95% cured.

This longer curing time can extend your project timeline. If turnaround is a priority, you will be better off with an air-drying finish.

Release of VOCs 

Some CVs are high in volatile organic compounds (VOCs), which release during application. These can cause environmental and health concerns. Always use personal protection equipment (PPE) and ensure adequate ventilation when working with CV.

How to apply conversion varnish

Applying conversion varnish requires careful preparation and adherence to specific techniques. We always recommend using a professional to guarantee results. But if you’re curious about how it works or confident enough to do it yourself, here’s an overview of the process:

• Prepare the cabinet surface, ensuring the wood is clean and smooth.
• Prepare your environment, setting the correct temperature and using proper ventilation.
• Mix the two components thoroughly by following the manufacturer’s instructions.
• Apply with a spray gun for even and efficient coverage (you can also paint conversion varnish on with a brush for a more accessible option).
• Use even coats to ensure proper overlap between layers and avoid excess buildup.
• Allow each coat to dry according to the manufacturer’s recommended time.
• Lightly sand between coats using fine-grit sandpaper to promote adhesion. 
• Don’t apply more than three coats. This keeps the finish from cracking.
• Allow the conversion varnish to fully cure according to the manufacturer’s guide.
• Buff and polish the cured surface (optional) to enhance the sheen.

The importance of conversion varnish maintenance

Regular maintenance is an investment in the long-term beauty and durability of your cabinets, and conversion varnish is no exception. While CV is high-performing, caring for the varnish through regular cleaning and general upkeep contributes to its clarity, luster, and overall durability. 

Here are tips for preserving your varnish’s aesthetic appeal and protective qualities.

• Clean regularly with a soft cloth and mild cleaner.
• Avoid abrasive chemicals that could damage the finish.
• Dry the surface immediately after cleaning to prevent water damage.
• Wipe up spills promptly to prevent potential staining.
• Use window coverings to minimize prolonged exposure to direct sunlight.
• Protect your cabinets from extreme temperatures and humidity levels.
• Periodically polish the surface with a non-abrasive polish to enhance its sheen.
• Use touch-up kits to repair minor blemishes.

Is conversion varnish right for me?

When deciding whether to use conversion varnish, take into account your budget, time restraints, and desired level of durability. 

CV is the best option for kitchen cabinet doors, offering unmatched resistance to wear, staining, and water damage. If your kitchen has a lot of activity, CV is a surefire way to minimize any damage and ensure all your renovation work doesn’t go to waste.

At the same time, if you’re on a tight budget, have a low-traffic kitchen, or will be applying the varnish yourself, CV may not be the best choice.

Spending all that time and money adding CV to your cabinet doors is unnecessary if you don’t use your kitchen a lot. You can find finishes that offer a good level of durability for a fraction of the cost and effort. 

Similarly, if you can’t hire a professional, you’re likely to misapply the CV, resulting in a host of problems and more costs in the long run. You’re better off playing it safe with something simpler, like a traditional varnish or lacquer. 

Learn more with The Cabinet Door Store

Ultimately, the choice of whether to use conversion varnish is yours. We hope the insights provided in this guide help you confidently navigate the complex world of wood finishes. 

When you’re ready to take the next step, The Cabinet Door Store is here to help. We stock a huge range of cabinet parts, including painted cabinet doors that come coated with an industrial-grade, post-catalyzed conversion varnish for extra longevity. 

All our doors are available in a variety of woods, stains, and cabinet door profiles. We even offer matching drawer fronts so you can achieve a cohesive look.

Browse our online shop today, or contact us if you have questions about a specific part of your project.