Wood Finishing: Torn Between using Seal or Varnish

Part 1/2

Being in line with wood workshops, I am frequently asked about the distinction between whether to seal or varnish a finished project. Both are efficient and great finishing methods especially when applied in an appropriate element.

Did you know that the internal component of wood comprise a lot of microscopic tubes or cells that run to and from the timber grain. These series of cells carry with them nutrients that are important for the growth of trees and, as soon as dried and cut, they continue to contract and expand under similar conditions of humidity and extreme moisture.

Even after a synthetic finished has been utilized to the wood surface, the wood continues to expand depending on the outside temperature in which it is stationed. It is not a method that you are going to find out easily but there are some ready indicators that this is not occurring. For example, during a wet weather, you may notice that an exterior garage door or a wooden gate will stick and swell a lot. You may even have a difficulty in opening a timber window. This is because of the fact that the wood has expanded as an outcome of excess moisture that was absorbed in the wood.

In turn, the expanded wood will basically revert back and dry out to its original condition, although sometimes minimal sanding down may be needed. Taking these basic factors in to consideration, when deciding what kind of finishing to apply to your wood projects, it helps to have an idea about little information beforehand.

 Herringbone flooring being varnished

Herringbone flooring being varnished

What is Varnish? Varnish is an infusion of oils and resins that are utilized and applied to the wood surface to supply a safety layer to protect against damage. Varnish is available in several formulations from matt finish to semi-gloss to gloss finish. Polyurethane varnish is the most commonly used varnish for finishing.

It is known that varnish does not specifically penetrate into the wood. It is the other way around. The first coat of varnish practically blocks the wood surface to supply added protection from unwanted moisture.

But, because of regular contraction and expansion of timber, the layer of varnish may perish and crack overtime which gives freedom for the moisture to go inside the wood and simply aggravating the problem.

So, are you enticed? You basically know something about the components and features of a varnish. On the next article, we will discuss some relevant facts regarding a sealer. And to conclude the topic, we will give you some tips and tricks on how to use either a varnish or a sealer. This article will aid you in choosing what to use as wood finishing. And after reading the whole of it, I am pretty sure that you will have something in mind.