Why Are My Cabinets Turning Yellow? A Guide to Types of Wood Finish.

Why Are My Cabinets Turning Yellow? A Guide to Types of Wood Finish.

With design trends increasingly moving away from stained finishes and toward solid colored "paints," one of the most common complaints were hear nowadays is "Why are my cabinets yellowing?"

The answer is simple; there's no chance they won't yellow if the finisher is using the most commonly available and popular coating on the market.

The vast majority of cabinet makers use pre-catalyzed lacquer to finish their builds, because it is cost effective, easy to work with, easy to touch-up or repair and provides great durability. Pre-cat lacquer is essentially the nitrocellulose lacquer that was popular from automobiles to furniture to instruments in the early 20th century, but with an acid catalyst added to increase hardness and prevent evaporation. Pre-cat lacquer is reasonably flexible and can move with the wood as it expands and contracts due to temperature and humidity. It resists most household liquids, chemicals and solvents, in addition to being fairly scratch resistant. 

However, pre-catalyzed lacquer suffers that same problem as the nitrocellulose lacquers that came before it, and which it is also made with; it will yellow over time. 

This is illustrated very clearly in older electric guitars, namely the colorful Stratocasters and Telecasters so sought after from the 1960s. An Olympic White finish was initially as bright as the pickguard, but yellowed over times as the resins in the coating aged.

So how do you prevent this yellowing from setting in too quickly? There’s a few ways to keep your cabinets brighter for longer.

  • Cleaning: use only an oil based polish, like OZ from Mohawk, or a neutral non-reactive glass cleaner, such as the ubiquitous Sprayway ammonia-free aerosol glass cleaner. Waterbased cleaners with Teflon-type additives are also a good call, and can help keep your cabinets cleaner between cleanings to boot. DO NOT use any cheap silicone-infused clearer, like Pledge, or anything with harsh solvents, like 409, anything with ammonia or bleach.
  • Exposure: UV rays accelerate yellowing, so if you can tint your windows, or draw the blinds during most of the day, it will ultimately help your white cabinets stay whiter.

Don’t want to deal with yellowing at all? Well, there a quite a few finish options that do not leave your with yellowing whites.

  • Conversion Varnish – these finishes are vastly superior to lacquer. Incredibly durable with a higher solids content than lacquer, a quality “CV” finish will also be much more scratch resistant and totally non-yellowing. However, being a two-component product, sometimes with proprietary reducers or retarders, they are always more expensive. They are also a bit more difficult to touch up compared to pre-cat. You won’t find the ability to seamlessly blend one coat into an existing coat as you do with lacquers. Refinishing is also a challenge; conversion varnish is very difficult to sand or remove without repeated applications of stripper and lots of sanding.
  • C.A.B. Acrylic – We are seeing more shops move toward C.A.B.’s as they do solve the issue of yellowing in the finish. Being a single component acrylic resin and not nitrocellulose, C.A.B.s won’t change color over time, but they behave similar to lacquers in the finishing process. Viscosity, reducing and retarding are in-line with what a finisher might be familiar with already from using a pre-cat lacquer. However, C.A.B.s are generally pricier, and we have seen issues with durability and in some instances, chemical staining or adhesion failures. They are certainly not as hard as a conversion varnish, and slightly less durable than a pre-cat.
  • 2K Urethane – The ultimate finish, two-component polyurethane finishes have been the standard for high-end European cabinetry for years. They aren’t as common in North America, but will certainly become more prevalent as their costs decrease. These urethane finishes already have a slight amber cast to them before they are even sprayed, as all polyurethanes do, both water-based and solvent-based. However, that tone will not change as the finish ages, and an experienced color-matcher may be able to reduce the appearance of some of that amber cast by manipulating the base coat to cancel that particular tone. 2K Polys are more expensive and require a more experienced finishing team to apply. These resins are incredibly resilient to chemicals, and remain flexible to move with the wood in different environmental conditions. Their scratch and abrasion resistance is unmatched.
  • Waterbased Urethanes – Waterbased products have made giant leaps in recent years in terms of user-friendliness, durability and price. They are now a viable coating system for a detail oriented, well trained finishing team to use in every step of the process. As mentioned above, being a polyurethane, these waterbased systems will have a slight amber cast. However, in a quality finish with UV stabilizers, that cast will not change over time after the material is cured. Waterbased stains, toners and solid base colors offer incredible hide and grain filling ability, and new formulations no longer raise the grain of the substrate. Higher end waterbased finishes are based upon a polyurethane resin that is both water and solvent dissolvable. You’ll find a few common ingredients between solvent and waterbased systems, namely alcohols and glycol ethers. These advanced resins work with these powerful reducers and retarders to lay out better, accept colorants easily and deliver a clearer, less “plasticky” finish. Waterbased polys are incredibly resilient, chemical resistant and hard wearing. We are also see waterbased conversion varnishes and UV-cured finishes that are among the hardest, most durable available for wood finishing. And best of all, no harsh odor!

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