Saturday, 23 January 2010

Outdoor Oak Furniture Finishes

We are currently making outdoor furniture. A grave, a memorial bench and a sculptural light piece.

A lot of research into using green timber and outdoor oak finishes has been carried out.

The main issues arise when water penetrates oak. It reacts with the high tannin content within the timber, resulting in 'blackening.' Also, the sun's UV rays will turn the oak to a silvery hue over time.

The aim is to avoid blackening whilst preserving the natural beauty of the wood and avoiding finishes cracking or peeling over time.

The best finish we have found so far is one coat of Barretine Wood Preserver followed by three coats of Osmo 420. The wood preserver protects against wood rot and fungi whilst the Osmo oil finish offers UV resistence and also contains biocide which helps protect against wet rot, dry rot and blue stone. The oil repels water and so prevents blackening. Osmo is also one of the greenest finishes out there.