Importance of the preparation of wood prior to finishing
At Redwood, we always recommend spending time thoroughly preparing the wood prior to finishing.
In this blog, we’ll look at the reasons why and give our top recommendations for achieving the best results for your next project.
Why is it important to prepare wood prior to finishing?
Preparing the wood prior to finishing can vastly improve the durability of the product and its ability to withstand wear and tear over time.
Water absorption will modify the physical properties of coatings and may cause chemical change. Properly preparing the wood will prevent water damage, shrinking, swelling and movement of the substrate.
Using the right treatments for your wood will minimise the impact of outdoor weathering and reduce the amount of maintenance required.
Thorough surface preparation can help to remove any imperfections in the wood and deliver a smoother, better finish.
Conform to British Standards and regulations
For outdoor joinery, you should select wood as per BS EN350 and BS EN335, which is good for exposed weather conditions. If the timber is not available, then it must be treated to conform to the BS EN 599-1.
Redwood’s top recommendations
Protect the V-joint and cross grained wood
When preparing your wood prior to finishing, it’s really important to give the cross grained wood extra protection to prevent moisture from penetrating the V-joint.
We recommend applying a V-joint sealant after priming, to prevent moisture entering and warping the wood and causing discolouration.
Sand the wood
To achieve a smooth overall finish and avoid ripping the substrate, an appropriate grade of abrasive paper should be selected to sand the surface.
The surface of the wood can be rougher if you sand across the grain. Power tools like an Orbital sander, belt sander, disc or drum sander can be used to get them as fine as possible for a smooth surface.
Fill damaged surfaces
Prior to coating, any cracks, damaged and defective surfaces should be filled with suitable material or wooden components.
Small gaps and cracks can be filled with a fine surface filler. For significant damage and holes, the wood can be filled with hard wax. Soft wax filler is not recommended for external joinery, due to exposure to extreme weather and temperature.
Rectify minor surface defects
Seal exposed end grain and knots with suitable solutions before applying the coating, to give the wood extra protection.
Clean and degrease wood
The working area should be kept clean to ensure an effective finish. Dust, salt, powder, contaminants and grease should first be cleaned from the wood.
Control the temperature
Coatings need to be kept at a controlled temperature to dry, cure and ensure long term performance and must be kept away from frost and cold draughts.
Cold weather can lead to extreme temperatures on the floor, so products should be stored on pallets or racks with adequate ventilation.
Treat the wood
Some timber, particularly tropical hardwoods like Iroko, Teak and Cedar, have natural oil and chemicals that should be thoroughly cleaned by using a suitable panel wipe before applying the coating.
Wood treated with linseed oil, tung oil, and Rustikal oil is protected against fungi. However, for outdoor use, treated woods need to be cleaned with a suitable panel wipe.
Follow the Factory Method Statement
The best way to protect wood is to follow the Factory Method Statement, which details a step-by-step guide to ensure user safety and enhance the lifecycle of the wood.
Use opaque finishes
An opaque coating provides more protection to an exposed wood surface. It is more durable and requires less frequent maintenance than a clear varnish.
It has good resistance to UV light, protects against moisture, oxidation and corrosive chemical agents, providing long-term protection against weathering.
For help finding a reliable solution for your needs, or more information on our Factory Method Statement, contact us on 023 9223 3310 or email email@example.com.