Ronseal crystal clear outdoor varnish is perfect if youre looking to varnish wood and keep its natural colour itll protect from the weather and doesnt yellow over time like other traditional varnishes crystal clear outdoor varnish is rainproof in 1 hour before you start make sure its a warm dry day above 10c and the wood is clean and dry also make sure you wear a face mask to avoid breathing in any dust prep stained or varnished wood give the wood a good sand to make sure the varnish sticks the