Ask the Builder: Oxygen bleach cleans teak

DEAR TIM: I purchased a used teak outdoor table from Craigslist. It was a great deal, but it needs some tender loving care. How do I clean it? Should I just pressure wash it? After cleaning it, how should I protect it, or can I just let it weather to a natural color? I want the wood table to last as long as possible. – Ann P., Raleigh, North Carolina

DEAR ANN: Craigslist is a great place to find fantastic bargains. I’m stunned at the tools, home improvement materials and furniture you can find for amazing prices. Teak outdoor furniture sets are popular where I live and I see several on the website right now.

Teak is a great wood for outdoor use. Just ask any sailor: Teak is commonly found on boats that sail the high seas, both as decking and as trim.

To keep teak looking like new, you should protect it with a pigmented sealer. If you don’t, it will weather to a natural gray and cracking may start to occur. Small checking cracks can allow water to penetrate deeper into the wood, causing the cracks to get larger.

I would avoid using a pressure washer on your teak table. Pressure washers are the easy way to clean, but they can also damage furniture-grade teak lumber.

I prefer to use certified organic oxygen bleach to clean teak. These products are readily available online and at some stores. Oxygen bleach is not harsh like chlorine bleach. Chlorine bleach can whiten the teak wood fibers because it’s such a strong oxidizer. I don’t think you want a white table, but I could be mistaken.

I’ve had the best luck cleaning teak wood when it’s dry. Try to work in the shade, if possible. Mix one cup of powdered oxygen bleach for each gallon of hot tap water. This will cut through dirt, algae, mold, mildew and most of the oxidized wood stains or sealers that might be on the teak.

Stir the powder in the water until it’s completely dissolved. Pour the solution into a standard hand-pump garden sprayer. Adjust the nozzle so it applies a spray to the wood. Spray the entire table, including the underside, and keep it wet with the solution for at least 15 to 30 minutes.

If the solution looks like it’s soaking in, spray the teak again. You should see countless tiny white bubbles on the surface of the wood. This means the oxygen bleach is working and helping loosen the dirt, failed stain and sealer and other things from the wood.

At the end of the wait period, use a hand scrub brush to clean the table. The brushing action takes the place of the destructive force of the pressure washer. You always need to mechanically agitate the surface of anything you clean. A standard household scrub brush will do a magnificent job on teak.

As you scrub, use a constant low flow of water from a garden hose to rinse away all the dirt and failed sealer and stain. You should see dramatic results as you scrub. The longer you allow the oxygen bleach solution to soak – even up to an hour – the less you have to scrub. If you have to scrub too hard to get great results, stop and reapply more oxygen bleach solution.

In almost all cases, the teak will clean up very well. Be sure you rinse the table well as you scrub. Allow the table to dry in the shade, then apply a synthetic-resin sealer or stain. Be sure it says on the label that it’s approved for use on teak. You want a sealer that will soak into the teak wood and not form a film on the surface. Film-forming sealers will eventually peel and your table will be a mess.

It’s normal to have to clean and reseal your teak table every few years.

If the table is in direct sunlight most of the time, the sealer will fail faster. If you can store the table in a shed over the winter, you can extend the life of the sealer.

Each spring, just clean the table with liquid dish soap and water, if the sealer is in good shape. It’s a good idea to use this soap and water during the summer season to remove invisible sugars excreted by nearby trees. These sugars are food for mildew, mold and algae.