Fairground signs

I was recently commissioned to construct 8 large fairground signs for The Oasis of the Seas cruise liner. The signs had to look old and rusty but at the same time had to be able to withstand the harsh marine environment. I made them from marine grade stainless steel as this would not rust. They were laser cut and then welded together, primed and painted. I then varnished them, splattering a very diluted dirty brown paint on the wet varnish to give an aged effect. I also sprinkled cast iron powder around the rivets. When the varnish was dry I mixed up a solution of cast iron powder and varnish and applied this to the areas where rust would naturally occur. The rusting process was accelerated by painting the rusted areas with vinegar.