Over time, teak furniture weathers and turns from brown to a shade of grey. Keeping it oiled with teak oil prevents it from turning grey but requires diligence and a considerable amount of maintenance. Some people like the worn and weathered appearance of greying teak. Others like the rich brown of the newer and well-moisturised teak. Perhaps you like neither. If that's the case, paint teak to match any outdoor design scheme.
Clean the teak furniture with a mixture of water and mild dishwashing soap. Put 1 tbsp of soap in the bottom of a bucket and fill the bucket with water. Dip a sponge into the soapy mixture and scrub the furniture to remove all traces of dirt and grime. Move the furniture into a sunny spot to dry.
Sand the furniture with the palm sander and medium-grit sandpaper. Since you are planning to paint the furniture, sand only the top layer. Create a rough texture on the surface of the wood without getting down to the bare wood. Wipe away sanding dust with a damp rag.
Fill any cracks or holes in the wood with wood putty. Let the wood putty dry and sand over the top with the palm sander to smooth the surface of the wood.
Apply primer to the teak furniture with a paintbrush. Choose a good-quality deck primer. Prime crevices and hard-to-reach areas first and follow with the larger portions of the furniture, covering up paint seams as you work. Allow the primer to dry.
Apply deck paint in a light, thin coat, using a paintbrush. Allow the paint to dry and add another coat. Use two to three thin coats to improve durability.