The use of brass, copper and bronze found objects is essential in the creation of Steampunk fashion and gear. A bright brass gear or clock piece is sometimes called for but often a dulled and antique feel is more consistent with the look that a person is trying to get their hands on. Here I will go through step by step a few basic processes for patinas I commonly use in my Steampunk items.
The most common and possibly easiest patina to get your hands on the materials for is a dark antique patina. This antique feel comes from a substance called liver of sulfur. Liver of Sulfur is a mixture of Potassium Thiosulfate and Potassium Trisulfide. This is a toxic material and should be handled with gloves, goggles (no pun intended) and in a well ventilated area. This substance can produce a toxic gas if exposed to acids so use as directed. I use a formulation that can be had from the Rio Grande Jewelry Supply company. They are at www.riogrande.com. Most any online jewelry supply will have Liver of Sulfur. This patina works well on Brass, Copper, Silver, and Bronze.
#1 Preparing your brass, copper or bronze item.
When using patina it is essential that all oils be removed from from the brass object to be worked on. This includes the oils from ones hands. Often all that is needed is a good wash and scrub from a dish detergent. After this, dry the object with a paper towel, handle with gloves thereafter. One can increase the action of the patina by scratching the metal with sandpaper, steel wool or wire brush.
#2 Preparing Patina for use.
In preparing the liver of sulfur patina it is essential that one use hot water in the process. In my experience the patina will go on very slowly if the water used is cold. I usually take and set my items in a 5 gallon bucket in the workshop. I then boil water consistent with the amount required by the patina formulation's instructions. I then place the correct amount of patina in the 5 gallon bucket and add the boiling water to the gears and patina. Do this in open ventilation as you will likely get a sulfur smell. Stir this mixture and allow to react. You can periodically check your brass and pull out as needed. The brass will darken to its mature color as it dries.
#3 Post Patina
Take the items and place them in a bucket, rinse and discard the liquid Three times as this will get most the liver of sulfur off. Now the items need to be scrubbed with liquid detergent once again. At this point if the item is not dark enough you can repeat step 2 by using the existing still warm solution of patina in your garage.
#4 Disposal of Patina
If sealed and kept from the air you can reheat and use the patina again although its potency is reduced and this translates to longer curing times. Contact your city to find out how to properly dispose of your used patina as each country and state is different. Pouring it down the sink will create a potential toxic gas problem if the wrong things mix in the sewer or sink trap.
In conclusion, although this technique is not novel and is well know in the altered art and craft movement it is the easiest and safest patina for the home DIY Steampunk engineer to use. This patina should give you many options as you explore using distressing and wax relief techniques to get a one of a kind Steampunk piece.