Thursday, May 14, 2015

Knowing the Difference: Lacquer, Polyurethane, Shellac, and Varnish

By Gretchen Sawatzki

Not all furniture finishes are created equal and your needs can dictate the type of finish that is best for you. Believe it or not, shellac isn't the same thing as polyurethane, just as varnish isn't the same thing as lacquer. Here's to knowing the difference...

1). Lacquer

Image source
Lacquer is a solvent-based finish that contains plasticizing agents to create a very durable surface. It creates a shiny or glossy finish and can be easily applied using a brush or spray can. It dries fast and can make quick work of a refinishing job, however it can scratch and yellow over time. Maintaining lacquer is easy as it can be stripped using a paint thinner and then reapplied for a shiny, even finish.

2). Polyurethane

Plastic in liquid form, polyurethane is a very durable finish that comes in both water-based and oil-based variations, and comes in a wide variety of satin to glossy finishes.

 - Water-based polyurethane goes on clear and has low toxicity levels and little odor. It drys fast
    and is suitable for furniture not exposed to heat or too much sunlight.

 - Oil-based polyurethane has a slight tint to it and can change the overall look of the wood it is
   applied to. It takes a lot longer to dry than its water-based brother, and emits a harsh odor.
   When dried, oil-based polyurethane can withstand all types of climates, heat, and conditions.

The"shellac insect". Image source
3). Shellac

Shellac is a clear gloss finish that comes from a secretion of an insect called laccifera lacca that is mixed with alcohol. The insect is a native to Southeast Asia and India, and has been used by craftspeople in India as early as the 16th century. Shellac creates a shiny surface, and when hand-rubbed and applied in thin layers, can create a smooth, even surface. It is more delicate than other finishes, as it is can be easily worn away.  It is natural, non-toxic, and a great option for delicate wood furnishings, antique furniture, and historic woodwork.

4). Varnish

Varnish is a clear finish that is made from oils and resins. It is durable with a high percentage of solids, and needs to be applied with a few coats. It ranges from satin to glossy, and is best suitable for floors or outdoor woodwork. The finish creates a protective film and requires less maintenance than shellac.

Sources:
 diynetwork.com
 finewoodworking.com
 homeguides.sfgate.com
 refinishingfurniture.net
 wisegeek.org
 wkfinetools.com

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