All About Shellac, Lacquer, Varnish & Polyurethane.  What is the difference between them?  Which finish works best for which type of wood surface?

Shellac

What Is It? Shellac is made from the secretion of the female lac bug, found in Thailand and other parts of Southeast Asia. This dry substance is then mixed with alcohol to form a liquid.  For this reason, shellac is a fairly natural finish.  It generally lends a warm amber tone to wood, and provides excellent definition of the wood grain.

Best For:  Fine wood furniture. Shellac does not respond well to heat, so it would not be a good choice for tables or desk-tops.

Pro Tip:  Only buy the amount of the shellac that you need for the job at hand, as it spoils quickly in the can.

Lacquer

What is it? Lacquer is an extremely high-gloss finish made of synthetic ingredients.  Historically, lacquer was actually “shellac”, but once a synthetic version of lacquer was developed, the finish made from the lac bug was named “shellac” to differentiate the natural substance from the synthetic version.

Best for: Furniture for which you would like to obtain a very high-gloss finish.  While shellac lends an amber color to the wood, lacquer is 100% clear, and emphasizes the natural color of the wood itself.

Pro Tip: Most of the lacquers available on the market today must be applied with a high-volume, low-pressure paint sprayer, that costs several hundred dollars.  So this expense needs to be considered if you are a DIY-er and would like to go with lacquer.

Varnish

What is it? Varnishes are generally made from resin, drying oil, and a solvent or thinner.  Unlike the other finishes, they dry and harden very quickly and thoroughly.

Best for:  Any wood surface which will be exposed to water, such as boats, outdoor furniture, and exterior doors and trim.

Pro Tip: For best results, be sure to apply varnish with a natural-bristle brush.

Polyurethane

What is it? Basically, in the simplest of terms, polyurethane is liquid plastic, that hardens into a very hard, durable finish as it dries.  It comes in both water-based and oil-based forms.  Polyurethanes are generally considered to be the most durable of the wood finishes, and are very popular with DIY-ers.

Best For:  Water-based polyurethane is popular because of its low-toxicity.  It also low-odor. Because, like shellac, it is sensitive to extreme temperatures, it is best for bookcases, shelving, picture frames, and other wood items that won’t be exposed to heat.  There is a new form of water-based polyurethane called “Minwax”, which is a lot more durable, and this type can even be used on wooden floors.  Oil-based polyurethanes, on the other hand, are more durable than most water-based versions, and don’t have the heat-sensitivity. So this type is a good candidate for table or desk-tops.

Pro Tip: Always brush or wipe it on with the grain of the wood, for best results.

by See Jane Drill, Copyright 2016, All Rights Reserved