Fastener Tips | Choosing The Fasteners For A Pressure Treated Wood Application
Due to their high resilience, resistance to the tannic acid present in wood and affordability, galvanized fasteners are the ideal choice in wooden furniture and other wood products applications. The advantage of the fasteners that are galvanized over their stainless steel counterpart comes from the zinc-iron alloy that is spread evenly all across its surface. […]
Due to their high resilience, resistance to the tannic acid present in wood and affordability, galvanized fasteners are the ideal choice in wooden furniture and other wood products applications. The advantage of the fasteners that are galvanized over their stainless steel counterpart comes from the zinc-iron alloy that is spread evenly all across its surface. The uniform coverage ensures the fastener is free of weak spots that are prone to corrosion and/or damage. Moreover, because the alloy also protects the edges and corners, the fastener will maintain its original state and is completely shielded from the elements.
It is all of the aforementioned features that make galvanized fasteners a great choice for pressure treated wood applications. Following are some guidelines that will help you understand how pressure treated wood and galvanized fasteners work with each other.
Learn more about the chemicals used in pressure treated wood
The pressure treatment process implies adding a chemical preservative to the wood that makes the material less prone to rot, insects and vermin. While the most commonly used chemical for this purpose was the chromated copper arsenate, manufacturers stopped utilizing it a decade ago because the preservative proved to be extremely toxic for residential use. Nowadays, pressure treated wood manufacturers employ safer chemicals like copper azone and amine copper quat, both of which you can find at the local lumberyard.
Understand the galvanization process
Almost all fasteners designed for wood applications today are made of steel. Because steel has a moderate resistance to rust due to exposure to the elements and daily use, it needs to undergo a galvanization process, which implies applying a coating of zinc oxide onto the steel nail, screw or bolt. The method ensures that the fastener gains a higher resistance to rust and corrosion while maintaining its integrity. Currently, fasteners can undergo two types of galvanization processes, namely the hot dipping treatment that adds a thick zinc coating and prevents corrosion for prolonged periods of time and the electro-galvanization. The latter implies pouring a thinner layer of zinc over the fastener to provide a smoother and shinier finish.
Matching the wood with the fastener
Because they incorporate a slimmer protective coating, electro-galvanized fasteners are best used for indoor projects. Utilizing them indoors means the fasteners will not be exposed to acids, chemicals, saltwater, UV rays and for that matter, in projects involving pressure treated wood.
The hot dipped galvanized fasteners are significantly more resilient and can withstand harsh outdoor conditions. It is important to note that in time the protective layer of zinc will wear out due to the acids and chemicals utilized in wood treatment. Therefore, the higher the amounts of corrosives the fastener will be exposed to, the thicker the layer of zinc necessary for a longer lifespan of the fastener. When shopping around for galvanized fasteners for a pressure treated wood project, look for the “G185” standard on the packaging, as this indicates the zinc coating is sufficiently thick to be used with this type of wood.
