How to Varnish Teak
Teak is an extremely durable wood even when it is left untreated, and it ages very well, turning to a beautiful ash gray when it becomes weathered. It mainly grows in Burmese forests and it produces an abundance of natural oils that make it a fine grained wood which withstands every condition. This is why it is a highly popular wood for use with boat building and outdoor furniture. However, while it is not necessary to varnish teak or protect it, some owners prefer the non-weathered look of the wood and desire the extra security, particularly in the case of boats that suffer a lot of wear. Here is how you can use varnish to ensure the long life and natural color of your teak.
Step 1 - Prepare the Wood
Whatever the project you are working on, whether it be a boat, boat decking, outdoor furniture, or other exterior objects, you should begin by cleaning it. Let the wood dry out and then start using a gentle detergent solution, like laundry soap liquid mixed with water. Heavy abrasive detergents are not at all suitable for teak wood, as it is prone to being degenerated by such products.
Use a scrubbing brush or firm bristle brush with the soapy water and scrub clean any stains on the teak wood. Leave the soap to soak in and lift any stains or dirt from the fine grain of the wood and then rinse gently and let it dry thoroughly before you sand it.
Step 2 - Sand
Sand the teak wood down with a very fine-grit sandpaper on an electric sander. Since teak produces its own natural oils, these will travel to the surface of the wood as you work. You’ll want to sand the teak in the direction of the grain and keep your pressure steady and moving freely to avoid creating any divots or damage. You can use a block and sandpaper for smaller, hard-to-reach areas.
Step 3 - Brush and Varnish
Once the teak is sanded down, use a soft brush to clear off any debris and dust before applying the first coat of varnish. Oil-based polyurethane yacht varnish is the recommended type for outdoor teak, as it sets firm and gives a completely waterproof and weatherproof coating which will last for many a long year. Use a soft bristle brush to apply the varnish, always stroking with the grain of the wood.
Let the first coat dry completely and then sand very lightly with wet and dry sandpaper. This will give the second coat a better surface to adhere to. Wipe the residue once more and then apply the second coat of varnish. Let that dry for at least 24 hours to properly set and harden. You may apply more coats as needed, but once you finish, your outdoor teak should be set for use.