There are a number of products available which will help retain the colour of new outdoor teak furniture and prevent the greying process.
But before applying any finish, leave furniture exposed to the elements for four to six weeks. It is important that it gets wet during this pre-weathering period. If it doesn’t rain or if your outdoor area is under cover, hose the furniture down thoroughly twice weekly to remove dust and natural oil. This will also open up the grain and allow the finish to penetrate the pores of the timber more effectively.
You will notice that when the timber gets wet for the first time, it will feel slightly rough when it dries again. This is called “grain lift” and is quite normal. Sand very lightly with 240 grit sandpaper before applying your finish.
Always ensure that your furniture is bone dry before commencing this task and do not apply any finish to the runners of your extension table.