Steel blacking kit contains all items needed to blacken steel items. The kit uses just chemical action to turn steel items black within a few minutes just by dipping the item into the blackening solution. This process will also work for items that have been previously plated with zinc (not...
www.chronos.ltd.uk
I bought ~100ml bottle which was about a tenner, cant see it on their site though.
I apply with a paintbrush and gives a really nice effect.
:edit: Just checked, its the 1L bottle I have and its still on their site for £15.
Having wire brushed a lot of the paint off, and left it a few days, I actually quite liked the finish.
So lacquered it up and made a new base for it from a bit of less rotten timber.