A look at Pre-cat Lacquer

If you love lacquer but wish it was more durable, take a look at pre-catalyzed (pre-cat) lacquer. It retains the best qualities of traditional lacquer but provides a harder surface that better resists abrasion, thanks to a catalyst (think of two-part epoxy) that initiates a chemical reaction as the finish dries. Lacquer thinner remains the vehicle for pre-cat, but the resins vary from traditional lacquer formulations.

"Pre-catalyzed" means the manufacturer or dealer adds the hardening agent before you receive the product, photo above, you would mix post-catalyzed material in your shop.

The lowdown on lacquer
Lacquer, consisting of various resins dissolved in lacquer thinner, has proven a versatile finish for almost a century. Pro finishers and furniture manufacturers love lacquer because it sprays on smoothly and evenly without sagging or running, builds fast, and dries quickly. It can be clear or pigmented, and its hard, flexible surface polishes to a high shine.

And it's forgiving: To repair damage, just spray on more lacquer. The new coat partially dissolves the existing film and blends into it.

The unique nature of lacquer thinner—it's a blend of several solvents that evaporate at different rates—accounts for those winning properties. The thinner starts to evaporate as soon as the spray leaves the nozzle. By the time the finish hits the wood, it has already started to dry. This quick drying makes lacquer challenging to apply with a brush—for brush application, buy a specific "brushing lacquer" formulation.

When to use pre-cat lacquer

Versatile and durable pre-cat lacquer makes a great finish for indoor furniture and cabinetry. Think of it mainly as a big-project finish (see A question of quantity, shown below). Once dry, pre-cat lacquer rates safe for food contact and resists damage from most food items, water, and alcohol. But, it isn't as impervious to damage as polyurethane. Lacquer imparts a rich glow, and the finish feels nice to the touch.

"A question" chart

Applying pre-cat lacquer

Lacquer works best as a spray finish, applied to dry wood finish-sanded to at least 220 grit. High-volume, low-pressure (HVLP) spray equipment proves best for application because it greatly reduces bounce-back and overspray compared with conventional high-pressure spray guns. Nonetheless, you should wear safety goggles and a respirator suitable for organic vapors when spraying pre-cat lacquer.

Provide adequate ventilation, photo below. On a nice day, spray outside in your driveway or on the patio; the lacquer dries quickly enough that bugs and dust won't mar the finish.

Man w/spray gun and captions
Avoid breathing lacquer mist or getting it in your eyes. Ventilate the finishing area and keep the air moving to prevent vapor concentration.

Spray light coats to build the finish. Smooth, slightly wet coats reduce the need for between-coats sanding. If you do sand, let the finish dry an hour or so. (Follow the manufacturer's recommendations.) Wear a particulate mask when sanding.

 

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