Teak wood contains natural oils which help prevent it from rotting or deteriorating in a natural environment. Unfortunately, these oils also cause teak to turn gray or black due to mold and mildew feeding upon the oil.
On this page, we describe how to clean and protect teak. We also describe teak treatments such as oil, varnishes and sealers.
There really isn’t any secret to cleaning teak except that it requires some elbow grease (nobody has figured out how to package that yet).
There are basically two reasons to clean teak. First, you want to remove the black and/or gray color (actually mold & mildew) from the wood and get a more natural look. Second, you need to kill all the mold and mildew spores present so they won’t continue to eat the teak oil and discolor the wood.
The right way to clean teak
To clean teak, all you really need is a bottle of “teak cleaner”. These products are formulated to kill the mold and mildew and restore the natural wood color. There are generally two types of teak cleaners, one-part and two-part cleaners.
One-part cleaners come in a single bottle and use a mild chemical to clean the wood. We prefer one-part cleaners because they are much gentler. Because they are relatively mild, you need to work the cleaner into the wood with a bristle brush and let it sit for 5-15 minutes before rinsing it off. While rinsing the wood, use bronze wool to rub the surface (in the direction of the wood grain). This opens up the pores of the wood to remove all of the cleaner ensure that the wood is as clean as possible.
Two-part cleaners come in two bottles and typically consist of a harsh acid and a neutralizer. The first part (the acid) chemically cleans the wood, killing the mold and mildew spores and removing the black and gray color. This step works faster and requires less work than for one-part cleaners, but the harsh acid also raises the wood grain (making your wood rougher). The second part is a neutralizer which counteracts the acid, allowing you to rinse off the teak safely. We generally discourage the use of two-part cleaners because of the damage they can do to your teak and the environment.