For Teak. One of the endearing qualities of teak is its amazing resistance to the elements. Teak can be left outside untouched and untreated for many years and over time the original colour will weather and soften to a silver-grey. If you wish to remove the silver-grey appearance and natural day-to-day grime, use Westminster Renovator and Westminster Cleaner. These specially formulated products are a dual action treatment, strong enough to work quickly and easily to return the wood to its original brown patina. Follow these treatments by thorough drying and a gentle sanding, with a fine sandpaper to smooth any raised grain. The sanding also brings back the new colour, and removes white patches which appear after the cleaning/renovating process. Teak can also develop black spots, which can be caused by teak oil (which Westminster do not recommend), as well as metal particles commonly found in guttering, scaffolding and railway tracks etc. After a period of time teak can show cracks, especially in end grains. These are quite natural and do not detract from the timbers strength or durability.