If the wood is clean, simply apply a coat of the same mixture used previously, wiping off any excess after 5 to 10 minutes. If you don't know the brand of the oil used, you can use Brio finishing oil from Prato-Verde, which is compatible with most popular brands.

If the wood is slightly dirty, it's recommended to clean it with a damp cloth and a mixture of Black Soap and water and wait for an hour before applying the oil. Generally, unless linseed oil was used which tends to give an orange tint over time, the wood should not have changed color after all these years, but it may be slightly dehydrated due to winter heating.