Clean the tubes off with a little steel wool.
Light the candle and move it at a 45-degree angle above the metal surface, allowing a liberal amount of wax to drip from the candle. The angle increases the amount of wax that can become liquid at any given time by increasing the surface area being heated. A steeper angle causes the melting wax to extinguish the flame, and a shallower one decreases the wax’s flow.
After the wax has cooled and hardened, spray the surface of the steel with tap water and cake on a large amount of dry salt. The action of the moisture and salt set the patina on its way.
Mist the salted surface frequently with the spray bottle, keeping it moist but not dripping wet for a week or more. In eight to twelve days the patina will have set on the surface and etched itself into the steel.
To finish the piece, choose one method: (a) Scrape the wax off with a one-sided razor blade, leaving the non-patinaed surface below exposed. This can then be left to slowly catch up with the rest of the finish, leaving a subtle shading, or sealed with a coat of oil, which will create a sharper contrast on the surface. (b) Melt the excess wax off and burn the remnants into place on the surface of the steel using a gas torch.
A patina that has been sealed in wax that was flamed into place will last a very long time. The wax as it dissolves and lodges in the texture of the steel will also tend to darken the finish slightly. This can leave beautiful effects ranging from subtle patterns of light and dark to large areas of dark against a brighter ground. Experiment with small pieces of steel. Try differing amounts of salt to water to see what works best for you. The same goes for using wax as a resister—play around with it and try different oils, such as canola or mineral oil, for their finish characteristics. When you are ready to install your bollard, set it in a hole with about a third of the total length below grade, then backfill the hole with dirt. Use a level to make sure the bollard is plumb and straight.