Wooden picnic tables are normally constructed of redwood, cedar, treated lumber, pine or teak. There are five main categories of finishes that are commonly used: exterior varnish, clear waterproofing sealant, transparent or semi-transparent coloured stains, solid coloured stains and paint. The best finish varies by wood type.
Redwood is occasionally used to construct wooden picnic tables because of its natural colour and its ability to endure harsh weather. Because of its natural colour, redwood is difficult to finish with a transparent or semi-transparent coloured stain. If you do use one of these, first apply a small test spot to the underside to see what the colour will look like once finished. Paints and solid coloured stains are not recommended for redwood. While they will protect the wood, they will hide the natural beauty of the wood. Thus redwood is best finished with exterior varnish or clear waterproofing sealant.
Cedar is often used to construct picnic tables because of its durability and beauty. The preferable finishes for a cedar picnic table are exterior vanish or clear waterproofing sealant, both of which will bring out the natural colour and beauty of the cedar while protecting it from the elements. Transparent or semi-transparent coloured stain may also be used. If you use one of these, apply a small test spot on the underside to see what the colour will be once it is finished. Paints and solid coloured stains are not recommended for cedar. While they will protect the wood, they will hide the natural beauty of the wood.
Treated lumber is a common material for picnic tables because of its ability to withstand weather extremes and its relatively inexpensive cost. Because of the colouring of the chemical treatment, exterior varnish, clear waterproofing sealant and transparent or semi-transparent coloured stains are not recommended. Solid coloured stains or paint come in a wide range of colours and work well on treated lumber. These finishes are primarily for decorative purposes only because the chemical treatment will keep the wood from rotting.
Pine is very common material for picnic tables, but one which must be finished in order to protect the wood. All types of finishes work well on pine. Choosing a finish is a matter of personal preference and the desired look of the completed project.
Teak is occasionally used to construct picnic tables. It is the most beautiful material option but also by far the most expensive. Because of this, only exterior varnish or clear waterproofing sealant should be used on teak.