Wood Varnishes

Wood varnishes in New Zealand

Stains and treatments are necessary elements for making the most out of wooden floors and decks, especially in New Zealand where they can provide extra protection from the elements at the same time. Wood varnish is a clear, transparent timber finish typically composed of drying oils, gums, and an activating agent such as a thinner or solvent. It comes in a variety of formulas that can be based on anything from polyurethane to resins. This type of product is typically associated with wood; however, certain formulas can also be utilised as metal finishes. 

Unlike timber stains, most varnishes appear colourless, while some varieties may contain tiny amounts of yellow or orange. The surface finish is moderately to very glossy and ideal for furniture and floors.

Key ingredients in wood varnish

• Oils: The main component of a varnish formula creates a layer that will harden when dried, resulting in a reliable protective coating. The choice of oil determines the final appearance of the wood, its colour, and finishing gloss. 
• Resin: This supporting ingredient adds strength and body to the finished layer. Many compounds, such as tree resins, have a natural origin. Resins can be obtained from insect secretions and organic polymers, but also from plastics. 

The choice of resin and its proportion to oils define the character of the finish, from hard and brittle to flexible and weather-resistant types. Also, the resin content can affect the type of finish, from satin to high gloss. 

• Thinner: Oils and resins need a solvent to help the application of the finished product. The thinner can be anything from turps to white spirits and even water, and its role is to evaporate its liquid content so that the coating layer can cure and harden. Its proportion to other ingredients determines how liquid the final product will be. 

Types of wood varnishes and sealers

Acrylic

Quick-drying and non-toxic, these water-based compounds feature good UV resistance, making them suitable for both indoor and outdoor use. Acrylic finishes are clear, transparent, and suitable for use with materials other than wood - some formulas can even double as metal finishes. Their penetration power is lower than oil-based varnishes, and sometimes they do not spread as uniformly as other varieties. Acrylics provide gloss, satin, and matte finishes.

Exterior Finishes

These finishes are specially formulated for outdoor use in New Zealand, typically featuring added UV protection along with a fungicide for mould growth prevention. Most varieties allow the wood to breathe, being relatively flexible but slow to dry. 

Polyurethane Varnish 

Distinguished by the exceptionally hard surface they provide, these formulas are often used for floors exposed to heavy traffic. They provide heat, water, and chemical resistance and prevent early signs of wear and tear. The finish is clear and robust, available in gloss, matte, and satin. Polyurethane products do not penetrate below the surface of the wood and typically need a primer such as oil-based varnish.  

Yacht Varnishes

Initially designed for boats to protect their structure from the water, these products are remarkably flexible, with a high, oil-based gloss finish based on tung oil and phenolic resins. They are ideal for vertical surfaces and other places not made for walking. 

Alkyd Varnishes 

This category comprises all kinds of wood sealers based on alkyds - modified vegetable and natural oils.

Types of drying process

• Quick Hardening: Some varnishes harden faster than others, depending on the composition and the time needed for the solvent to evaporate. Fast drying can take up to several hours.
• Gradual Hardening: Long-drying formulas require a lasting reaction between resins and oils even after the solvent has evaporated. Once exposed to the air, they pass through oxidation and polymerisation processes, taking up to several days to achieve the proper hardness. 

Things to consider before choosing a varnish

Before selecting a wood varnish in New Zealand, several crucial factors should be carefully considered to ensure the longevity, appearance, and protection of your wooden surfaces. Firstly, understand the type of wood you are working with, as different woods may react differently to various varnish types, influencing the final aesthetic and durability. Consider the intended use of the wood – for instance, outdoor furniture requires a varnish with UV protection and moisture resistance, whereas interior pieces might prioritise a beautiful finish and ease of cleaning. The climate in your region of New Zealand can also impact your choice; areas with high humidity or extreme weather conditions necessitate varnishes designed to withstand such environments. Additionally, the finish type (e.g., matte, satin, gloss) can drastically affect the look of the wood, so select one that complements the style and function of the piece. Finally, factor in application methods and drying times, which can vary between products, to suit your project timeline and skill level.

If you need assistance in finding the right wood varnishes for your home or office, ArchiPro provides a connection to various professionals, ready to assist with all requirements and questions. Simply click "Contact supplier" on the product's page, or visit the supplier's website directly from the product's page.