Finishes for Mid-Century Homes

The National Register nomination for Greenmeadow records the walls as original deep-toned Philippine mahogany veneer paneling, under a ceiling that is the underside of two-inch by eight-inch tongue-and-groove redwood roof decking, with original floors of cork in the living areas and asphalt tile elsewhere, chosen to respect the requirements of the radiant heat system. The Eichler Network fills in the production detail from a former Eichler foreman: the product was plywood faced with a thin lauan veneer; Joe Eichler chose it for design and aesthetics rather than cost and, in the foreman’s recollection, really loved that wood paneling; a separate crew specialized in staining it and used the same color mix throughout the company’s building career; and the company would have kept using it had building code changes not forced a stop by the mid-1960s. Eichler extended the exterior grooved siding into the interiors and insisted on interior doors faced with the same paneling.

Philippine mahogany is not a mahogany. The USDA Forest Products Laboratory’s Wood Handbook explains that meranti is the commercial name for four groups of Shorea species from southeast Asia, most commonly Malaysia, Indonesia and the Philippines, and that the names Philippine mahogany and lauan are often substituted for meranti. The groups are separated by heartwood color and weight; merantis have a coarser texture than true mahogany, no dark deposits in the pores, usually interlocked grain, and axial resin ducts in long tangential lines on the end grain. The light red and dark red groups are the ones that read as the honey-brown Eichler wall, and the Wood Handbook tabulates their shrinkage: 4.6 percent radial and 8.5 percent tangential for light red and red lauan, 3.8 and 7.9 for dark red, green to oven-dry.

The finish on it was thin. The Eichler Network’s restoration piece describes the panels as thin wood with an extremely thin veneer, covered with an oil-based finish, whose owners prize the naturally finished panels with their subtle sheen; its sources warn that the veneer cannot be sanded without sanding through it, that sun exposure creates a different tonal quality that is impossible to remove, that picture-shadows show, and that the sort of Philippine mahogany Eichler originally used is no longer available. All of which means an Eichler kitchen is finished beside a wall that is sixty years old, variable in tone from room to room, and not restorable to a single color. The new cabinetry has to be designed against that wall as it is.

A clear finish is the first choice for walnut and rift oak, because the species were chosen for their color and a stain would only argue with it. The question is then the film. As our finish systems article sets out from the Architectural Woodwork Standards, the systems differ by how they harden: nitrocellulose lacquer by solvent evaporation, rated 2 for general durability and 1 for solvent resistance but 5 for repairability; conversion varnish by acid-catalyzed crosslinking, rated 4 for durability and 5 for solvent, stain and heat resistance; catalyzed polyurethane by two-component crosslinking, rated 5 and 5; and penetrating oil, rated 1 for durability and 5 for repairability. The original paneling was an oil. A working kitchen beside a glass wall is not the place for one; we specify a catalyzed clear film and keep the sheen low so the surface reads as wood rather than as coating.

A stain is the right tool in two cases. The first is a teak-look alternative, where sapele or African mahogany is toned toward the warmth the owner has in mind. The second is matching: where new paneling is being added to repair or extend the original, the new lauan is stained to sit beside the old, which the Eichler Network’s restorer describes as the usual approach — sometimes staining panels darker, more often installing new paneling so you get something consistent. A stain under a catalyzed film is a durable system; a stain under an oil is the original system and ages the way the original did.

Paint is the honest third option and the one the Eichler Network’s sources say many owners now prefer, with smooth white walls replacing paneling many found too dark. A painted slab door in a muted tone, kept matte, is correct in an Eichler kitchen so long as the plane stays flush and the hardware stays out of sight; it is the door profile and the shine, not the color, that make a painted kitchen look wrong in a post-and-beam house. The core under a painted door is MDF, flatter out of the press than plywood, and the film is a pigmented conversion varnish or catalyzed polyurethane rather than a brushed enamel, for the durability figures above. Sheen, in every case, stays low: the paneling has a subtle sheen, the glass has a great deal, and the cabinetry should not compete with either.

The Sacramento district plan describes the environment: radiant heating embedded in the slab, houses not originally designed with much insulation, and passive cooling through window placement and cross ventilation. The Greenmeadow nomination notes that the original floor coverings were chosen with the radiant system in mind. A cabinet base sits directly on that slab, and in winter the toe-kick zone is the warmest, driest air in the room. Wood responds to the moisture content of the air around it, and the Wood Handbook puts the equilibrium moisture content of wood at 70 degrees Fahrenheit at about 6.2 percent in 30 percent relative humidity and 9.2 percent in 50 percent. The Forest Products Laboratory recommends installing interior woodwork at an average of 8 percent moisture content across most of the United States. A cabinet built at 8 percent and stood over a radiant slab through a dry winter will move toward the lower figure at its base before it does at its top.

That is a design fact rather than a defect, and the responses are the ordinary ones done carefully. Solid components are kept narrow and quartersawn; wide surfaces are balanced veneered panels over a stable core, which is also what a flush slab door wants to be; every cut edge, and especially the bottom edge of a base cabinet and the toe kick, is sealed, because an unsealed MDF or particleboard edge is the part of the cabinet that takes up and gives off moisture fastest. Our cabinet box construction article covers the substrate behavior in detail.

The glass is the other half of the environment. Afternoon sun through a floor-to-ceiling wall puts ultraviolet light and daily temperature swing onto the cabinet faces nearest it, and the Eichler Network’s observation that the lauan paneling has faded unevenly over sixty years is the demonstration. A catalyzed clear film with ultraviolet inhibitors slows the change; it does not stop it. The honest practice is to choose species that age gracefully — walnut lightens and warms, white oak yellows gently, cherry darkens quickly and is usually the wrong choice beside a glass wall — to keep the sheen low so the change is not a change in reflectance, and to lay out the plan so the tall storage is not on the sunniest elevation. A finish that will look the same in thirty years is not available; one that will look right is.