As soon as you recieve them from the factory put a coat of 50:50
varnish and meths or rubbing alcohol on them.

This will help preserve them from contact with water, iron and grubby
paws, all of which will stain them. If they are already on site, sand
them down to remove all such marks and stains and paint them with the
above mixture.

Once in situe, further coats of a slightly stronger mix will ensure
their good looks will be maintained.

Clear preservative might be used first. If it is heartwood it is not
really necessary. Do not put anything on top of preservative until the
wood is thoroughly dry. Whiter outer wood must be treated in the same
way as any other hardwood as it is no more insect or rotproof than they.