Q: The veneer on our bathroom vanity is separating where water drips down. Is there a way to fix this?
A: Unfortunately, there is no easy or sure way to repair the damage to your vanity. Like many other furniture and cabinet pieces these days, it’s made of a type of particleboard wrapped in a thin layer of vinyl. Known as thermofoil, this veneer is thinner and more flexible than the plastic laminate that’s been used for decades on cabinets built of particleboard or plywood. That kind — known as high-pressure laminate because of the process used to make it, or by an early brand name, Formica — has to be glued on, and it’s suitable for only flat or gently curving surfaces. Vacuum Laminating Machine
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Thermofoil costs less and offers more design options, so it’s found on more pieces these days. The vinyl is thin, so when manufacturers heat it and put it in a vacuum press, the laminate conforms to even intricate shapes that a computer-controlled milling machine cut into the underlying particleboard, usually a type known as medium-density fiberboard, or MDF. This means thermofoil cabinets or furniture can resemble frame-and-panel construction or even bead board, features once possible only with high-end cabinets and furniture made of natural lumber.
If delamination occurs with high-pressure laminate, it’s usually limited to the thin strips that cover edges. If the laminate on a larger surface, such as a door front, comes loose, it lifts up as a flat piece. Thermofoil is much more susceptible to delaminating or bubbling up, especially when exposed to heat. Problems often show up on cabinets over a coffee maker or toaster, or next to an oven. On a vanity, an edge near a hair dryer runs is especially vulnerable. It’s relatively easy to reattach high-pressure laminate or thermofoil with contact cement, provided the underlying surface isn’t damaged or distorted.
But the underlying problem with your vanity — and with many thermofoil cabinets and even some laminate cabinets — isn’t with the veneer as much as it is with the particleboard underneath. Particleboard consists of randomly arranged wood fibers, glued together and pressed into flat sheets. Because the fibers are wood, they swell when they absorb moisture. But unlike with natural wood, which shrinks back when it dries, particleboard that swells never goes back to its original shape because of the random orientation of the wood strands. (Plywood is less susceptible to permanent damage.)
Swollen particleboard is very difficult or even impossible to repair, so it’s likely you will need to replace the vanity if you don’t want to live with how it looks now. But before you invest in that, you might try this.
First, gently pull back the thermofoil as far as it easily gives way. Do not force it or the plastic might snap off. With a sharp chisel, gradually pare away the wood fibers that are bulging out. Have two hands on the chisel, with one pushing forward and the other guiding the cut and acting as a break so you don’t lose control and cut more than you want. If you are right-handed, your right hand will be the pusher, in the back, and your left hand will be the guide, positioned at the front of the chisel, close to its cutting edge but behind it so you don’t get cut. Starting at a side edge of the damaged piece, pare in circular motions toward the end of the bulge. Take off only a thin layer at each pass. If you are lucky, you may be able to trim off all the swollen particleboard without nicking the laminate.
If you succeed, spread contact cement over the plastic and the section of particleboard where the laminate lifted. Dap Weldwood original contact cement ($2.99 for 0.67-ounces at Michaels) comes in a little tube with an applicator tip, but have a small disposable paintbrush handy to smooth the glue evenly over both surfaces. They should look glossy. Wait about 15 minutes for the glue to dry enough to become tacky. Then press the plastic back into place. It will bond instantly wherever the two surfaces meet, so to avoid a bubble, press the lifted section in place starting from where the veneer is still attached toward an outside edge. No clamps are needed.
If this doesn’t work and you decide to replace the vanity, you might look for something other than thermofoil. Even some companies in the business of selling thermofoil cabinets and furniture estimate the life span at only 10 years, in part because it is so difficult to repair. Bathrooms are one of the most frequently remodeled spaces in a house, but the job shouldn’t need to be done that often.
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