a fine finishing primer

What is the finest finish for my furniture?

I hear this question a lot. My stock answer: it depends on what you want.

What will you be using the piece for?

How much use/traffic will it get?

What kind of look do you want?

Do you want the finish to be repairable?

For all the variables, there are only two basic choices for fine finishing: lacquer or oil.

By ‘lacquer’, I mean any finish that lays on top of the furniture surface. This includes varnish, polyurethane, acrylic, latex as well as the so-called ‘high tech’ finishes like polyester, catalyzed varnish and catalyzed polyurethane.

fine finishing - lacquer

 

These are also called ‘film finishes’.

 

 

 

Film finish? This is a trade term referring to a material that’s laid on either by brush or spray. It goes on as a liquid and when the solvents evaporate, a ‘sheet’ or ‘film’ of the material remains, wrapping the piece of furniture.

 

Oil is any product, mainly linseed, tung or soy derivative, that penetrates the surface of the wood and forms a bond called a polymerized finish.

fine finishing - oil on cherry

 

Polymerized finish? Not as complicated as it sounds. This refers to any finishing material that penetrates the surface of the wood, joins with the wood fibers and through the heat generated from hand-rubbing, forms a protective layer that’s actually part of the wood itself.

Aren’t there more choices?

Nope.

That’s basically it. Sure, there are slight differences between lacquer and varnish and polyurethane but that has more to do with performance than with kind. Besides, nowadays with much tighter regulations on the amount of fumes allowed in the evaporation period, more and more film finishes are waterborne and/or blends of many kinds of materials. It’s hard to find a lacquer anymore that’s pure nitrocellulose lacquer – the old stuff – and not an acrylic. Polyurethane and varnish are both blends now of many different substances all meant to limit the amount of ‘fuming-off’ during the drying process.

The only other choice that a film finish offers is sheen level. That is, you can specify glossy, satin or matte.

With oil, there used to be only linseed oil and tung oil. Nowadays a new variety is available that’s made from soy products and has superior polymerizing – read protective – qualities. It even smells wholesome.

Oil’s sheen level is somewhere between matte and satin, depending on the wood and how vigorously it’s rubbed.

 

No one size fits all: there are pros and cons to each approach

A film finish has the reputation for providing better protection against damage from moisture and scratches; however, this feature can be misleading.

For one thing, the surface hardness and resistance to scratches, dings and dents is only as sound as the substrate; that is, even if you put the toughest finish on a softer species of wood, its scratch resistance is less than optimal.

For another thing, wood moves (see wood for not-woodworkers). As wood expands and contracts, it opens up tiny fissures in the film finish surface. Each of these cracks has the potential for allowing moisture to penetrate the surface and get between the wood and the film finish. Usually this occurs when liquid is left standing for extended periods of time on the furniture. Haziness in the finish, ‘clouds’ or white areas and particularly white rings are evidence that moisture has penetrated the film finish.

Few if any film finish moves elastically with wood. The very hardness that supposedly protects the surface eventually causes its degradation and decline. The harder the material, the more brittle it becomes over time, the less it moves with wood’s expansion and contraction and the more cracks and fissures open up, further compromising its seal. (In my humble opinion, film finishes are better suited for veneered pieces of furniture which aren’t prone to as much movement as solid wood and also need the protection that lacquer affords).

Polymerized finishes are not as scratch and moisture resistant as film finishes. Some would say they require more care and attention than lacquer finishes, which is true at face value; however, one of the primary advantages of oil finishes is that they can be spot repaired. If a scratch or other damage does occur, that area can be fixed without compromising the finish of the rest of the piece. With lacquer finishes, the whole surface must be stripped in order to perform a repair and then it must be refinished.

Perhaps the biggest pro or con to either kind of fine finish has to do with its look and this is an entirely subjective value. There are those who love to see a certain sheen level uniformly highlighting the surface of a well-made, handcrafted piece of furniture. Others prefer not to have something between them and the wood obscuring the figure and grain qualities they love so well. Over time and through many hands on it, an oiled piece develops a patina which has an alluring quality of its own, a testimony to its usefulness.

How a piece is finished represents the final choice of the soon-to-be owner of a custom made piece of furniture and the last touch of maker. It’s the culmination of a long process and while it’s probably the simplest stage, fine finishing is the most crucial on so many levels. An ill-considered choice or a hasty conclusion can compromise the integrity of an otherwise exemplary effort.

 

 

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