Beyond Lacquer: Cutting Edge Coatings for the Future
Since we have immersed ourselves in more advanced coatings from our new partner Renner USA, as well as the waterbased line from General Finishes and speciality coatings from Mohawk Wood Finishing Products, it’s time to reevaluate the options for finishers these days.
Gone are the days of being limited to just lacquer finishes for production cabinetry. Today’s marketplace is brimming with high quality coatings that are easy to spray and budget friendly. We’ll cover each option from the least durable to the hardest wearing.
Believer it or not, we do still see nitro lacquers being used for cabinetry, most notably in California. Given that California is limited to 275 VOC products, finisher’s in this market that insist on using solvent-based coatings are biased toward old-school nitro lacquer since it’s easier to spray and achieve a fine finish versus low VOC pre-catalyzed lacquer options.
In the real world, nitro lacquer is an antiquated finish, reserved only for antiques or instruments. Nitro lacquers are still the go-to for high end guitars and stringed instruments, as well as pianos and intricate furniture pieces, like clocks, radios and amplifiers. Because they are never truly done drying, nitro lacquer continuously evaporates, and allows the piece to expand and contract as altitude and humidity change. Literally dozens of coats can be sprayed, then easily polished aggressively to achieve a bottomless shine, which is why they are still the go-to finish for many piano refinishers.
Because they let wood breathe and adapt to atmospheric conditions, Fender and Gibson use proprietary formulations of nitro lacquer for instruments manufactured in the U.S. In fact, Finisher’s Warehouse supplies Gibson Guitars with aerosol cans of Mohawk Perfect Blend nitro lacquer for touch-up on their acoustic guitars built in Bozeman, Montana.
While nitro lacquers are easy to spray and build, they are a softer finish that is naturally hygroscopic (they will absorb moisture easily). They are not ideal for hard wearing surfaces, especially those subjected to any contact with water. As with any nitrocellulose material, they will yellow over time, and are prone to cracking and crazing as they continually evaporate and and the coating becomes thinner.
Touch-ups and repair are a breeze because each coat blends into the next.
Example products: Mohawk Finisher’s Choice (sprayable and aerosol), Mohawk Perfect Blend (aerosol), Mohawk Tone Finish Toners and Topcoats (aerosol)
Still the king of cabinet finishes, single component pre-cat lacquer is certainly the easiest finish to pick-up and spray consistently in a production setting. Pre-cat lacquers come in many formulations to suit VOC restricted markets, notably 275, 550, 635 and unregulated, or “conventional VOC” blend than can exceed 700 VOC. Many finishers can use a variety of reducers and retarders to easily and effectively improve leveling and address common finish issues (notably, blushing). Being the most commonly used finish in the industry, pre-cat lacquers are the most cost-effective products available.
Pre-cat lacquers are nothing more than nitro lacquer with an added acid catalyst that prevents the continuous evaporation of the nitrocellulose resin. This creates a harder, more resilient finish that is suitable for furniture and cabinetry. While they are more durable than a plain nitro finish, pre-cat lacquers will also yellow over time. This can extensively alter a color, especially whites and light stains, if subjected to prolonged UV exposure.
Many pre-cat lacquers, including Duracoat from Mohawk, are KCMA tested and will be adequate for your average kitchen or bathroom project. However, pre-cat lacquers are sensitive to prolonged exposure to water, cleaning agents and solvents. All too often we see failures on drawer fronts and doors that are mounted below sinks where a client has repeatedly splashed, spilled or otherwise hose the door repeatedly to the point of adhesion failure of the lacquer. While the catalyst improves durability, it also limits the flexibility of the coating, and overbuilding the final finish can lead to adhesion issues and finish cracking or crazing.
Pre-cat lacquers can have a short shelf-life, as the catalyst will yellow the resin in the can. Several companies manufacture post-catalyzed topcoats if the end user prefers to catalyze as needed, which does extend the shelf life somewhat. Like nitro lacquer, pre-cat finishes are easier to repair than other coatings as the repair will blend into the previous coat.
Example products: Mohawk Duracoat Lacquer (sprayable), Mohawk Pre-Cat Topcoat (aerosol)
Cellulose acetate butyrate, or CAB acrylic top coats, are another competing option for an easy to use single component finish. Because of their acrylic formulation, these coatings resist the yellowing that is common in pre-cat and nitro lacquer finishes.
In our testing, we found CAB acrylics to be more durable than nitro lacquer, but less durable than most pre-cat lacquers. CAB acrylics also tend to cost more than pre-cat lacquers. Touch-ups are generally not as straightforward as pre-cat finishes, since the coating does not blend into the subsequent coat. CAB acrylic touch-up aerosols are available, and we have had success loading these coatings into custom aerosols for pigmented touch-up as well.
We saw many shops using these coatings a few years ago, but they have fallen out of favor as industry trends move toward more advanced and more durable topcoats.
Example products: Mohawk C.A.B. Acrylic Topcoat (sprayable), Mohawk Final Finish Topcoat (aerosol)
Water-Based Acrylic Coatings
Water-based production coatings started with acrylic resins derived from the paint industry. As these formulations were developed and refined, they became a viable alternative to solvent-based finishing systems.
Many finishers have had negative experiences with commonly available, DIY-level acrylic topcoats (Minwax Polycrylic, Varathane Waterbased Topcoat, etc.). Milky coats when sprayed on, blushing issues during drying and a soft final finish that is inadequate for industrial use were issues for years. However, recent advanced formulations have turned the tide for these single component, cost-effective, odorless coatings.
The most advanced acrylic formulation is General Finishes Water-Based Pre-Cat Lacquer. Although the name can be misleading (there’s nothing “pre-cat” about it!), this advanced self-crosslinking acrylic finish rivals the durability of solvent-base pre-cat lacquer. Unlike the milky haze of previous generation acrylic topcoats, it goes on crystal clear, like a solvent-based finish. A cutting edge additive package increases leveling and helps eliminate blushing during drying.
However, as with any water-based finish, there is a learning curve if you are coming from solvent-based systems. Issues that can be easily corrected with a solvent pre-cat lacquer, such as blushing, orange peel, fisheye, light defects, etc., are typically not easily correctable in any water-based system. Touch-ups can be more difficult to blend, but Mohawk’s Water-Based Perfect Blend will level nicely over most water-based, and even solvent-based, finishes.
Example products: Mohawk Waterbourne Pre-Catalyzed Lacquer (sprayable), General Finishes Pre-Catalyze Lacquer (sprayable), Mohawk Water-Based Pre-Cat Topcoat (aerosol)
Conversion varnish, or CV, is an extremely hard finish that is the next step beyond pre-catalyzed lacquer coatings in terms of durability, while combining the clarity and non-yellowing of softer CAB acrylic topcoats.
CV’s are an acrylic resin that is catalyzed by the end user with an acid catalyst. Although post-cat products can be intimidating to less experienced finishers, we’ve found CV’s to be very user friendly as long as the mixing, application and pot-life instructions are followed closely. You’ll find pot-lifes ranging from 4 hours to 4 months, depending on the manufacturer. Being a post-cat, acid cured product, CV’s are often subject to less VOC restrictions in jurisdictions that cap coating VOCs. The improved leveling often associated with higher VOC formulations make CVs a very attractive, cost-effective and efficient option for finishers that are detail-oriented.
CVs are incredible cabinet finishes. Nearly impervious to water and all household chemicals, they are much more durable than pre-cat, CAB acrylic finishes or water-based acrylic finishes. However, their incredible hardness does make a CV finish less ideal for horizontal surfaces like tables and bar tops. CVs are also more of a challenge to repair, since it’s very difficult to get good adhesion over such a tough coating.
Mohawk’s Ultra Flo Conversion Varnish is their newest formulation. In our testing, we found it to level better than the previous Ultra Clear CV formula, with identical sanding and durability characteristics. All Mohawk CVs are self-sealing, but for ultimate build, moisture resistance and adhesion, they can be sprayed over a variety of single components (EZ Vinyl Sealer) and post-cat sealers (Ultra Clear Conversion Sealer, Post Cat Sealer).
Our newest conversion coating, Renner’s LPL, has been a huge hit with every customer that has tried it. It’s incredible 4 month potlife, combined with exceptional ease of application and outstanding durability make the LPL system an ideal choice for kitchens and bathrooms. Since we catalyze the product in-store, the guess work is gone. With a price point right in between pre-cat lacquer and conversion varnish, it makes the LPL a cost effective premium finish for solid color and stain projects.
Example products: Mohawk Ultra Flo Conversion Varnish (sprayable), Mohawk Ultra Clear Conversion Varnish (sprayable), Renner LPL Conversion Coating (sprayable)
Water & Solvent-Based
The most exciting developments in coatings have been in polyurethanes. Advanced solvent and water-based polyurethane coatings have been the standard in European finishes for decades, and are now becoming more common in the United States. These finishes offer vastly superior durability, flexibility, clarity and ease of application compared to the other finishes we’ve covered. Even better, we now have options from multiple manufacturers in single component and two component products in either solvent-based or water-based formulations.
Mohawk’s recently reintroduced Iso-Free 2K Polyurethane is an exceptional finish without the health risks associated with an isocyanate catalyst. We did extensive testing and had great customer feedback from this product when we introduced it in 2017, and we’re excited to see it come back to our shelves. This 2K urethane has incredible leveling, fast dry times and outstanding durability. Great clarity as a self-sealer over any wood stain, with the option of topcoating solid colors tinted into Mohawk’s Post Cat Sealer make it an ideal system for any project, from table tops to cabinet doors.
Renner’s 2K Polyurethane has been a huge hit since we introduced it to the Phoenix market last year. This highly advanced formulation is the result of decades of refinement and continuous improvement in the European marketplace. Available with a high-adhesion, easy to sand sealer, this system offers exceptional leveling, sandability and durability. By far the easiest high-performance coating to spray that we’ve tested, at a price-point that is simply unbeatable. We are also able to tint this product in any solid color.
Beyond that, Renner offers a 2-Component, Anti-Scratch Acrylic that is the ultimate finish for tabletops or bars. This formulation is harder than anything else we offer, while also being more flexible than a typical conversion varnish to reduce cracking and crazing as the substrate expands and contracts. This product excels overtop of open grain woods like oak and mahogany, and gives excellent grain wrap without looking plasticky.
Example products: Renner FO 2K Polyurethane Top Coat (sprayable), Mohawk ISO Free 2K Polyurethane (sprayable), Renner JO Anti-Scratch Acrylic Top Coat(sprayable)
We offer several options when it comes to single-component polyurethane coatings with water-based formulations. Water-based polyurethanes offer great adhesion, good clarity, easy sanding and great durability. When used for refinish applications, you’ll find water-based products are much less reactive to surface contaminants (silicones, grease, oils) than solvent-based coatings.
The General Finishes Poly and Renner 1062 clear topcoats are easy to spray and very durable coatings that can be tinted to any solid color. The products also have a sealer in their systems that can be tinted to solid colors, as well as with any water-based dye concentrates, wiping stains or pigments from Renner or General Finishes to create easy to apply spray toners.
Renner and General Finishers also offer a 2K Polyurethane in a waterborne formulation. The Renner 1234 and General Finishes Conversion Varnish are low-odor, low-VOC formulas that are perfect for field work where smell is a concern and ultimate durability is a requirement. These products spray very well from airless and air-assist airless equipment, and offer fantastic leveling and clarity. These work best as topcoats over tinted primers and sealers.
Renner also offers an exterior 2K Polyurethane, the Larice Exterior, that works great over any stain or basecoat. We are currently testing some sample doors going into the summer to see how it performs in the Arizona heat and UV.
Example products: Renner 1062 Waterbourne Polyurethane (sprayable), General Finishes Poly (sprayable), Renner YO 2K Waterbourne Polyurethane Top Coat (sprayable), General Finishes Conversion Varnish (sprayable), Renner Larice Exterior 2K Waterbourne Polyurethane Top Coat (sprayable)