A black chrome plating introduction
An introduction to black chrome brush plating; tips and trouble shooting
Our Black Chrome Plating Solution comes in parts A and B so that you can maximise its shelf life; supplying it in this form means it will keep for at least two to three years. Although black chrome plating is probably one of the most challenging of all of the brush plating processes that you can tackle, it can lead to considerable rewards. Black chrome plating is in great demand from the plumbing and sanitary ware industry and is used extensively in the restoration of interior household items such as door furniture and light fittings. Brush plating with black chrome should be undertaken on items that are for interior use only; it isn’t suitable for objects that will be exposed to outdoors conditions.
Because the process can be challenging, you need to be cautious about the size of the job that you take on, particularly at the beginning, when you are learning the skill. Areas of your work that are corroded will need to be stripped of chrome, nickel and any other possible undercoats, then ground with an abrasive to remove deep pits. Your work will then have to be polished to create a surface that can be successfully plated.
It is always best to plan a black chrome plating job carefully before you start. Black chrome forms a non-conductive oxide layer very quickly after plating and so it is best to start at one end of the item you are plating and to work methodically along to the other end and avoiding going back over what you’ve just plated. Gold flashing larger items helps you solve this problem.
When black chrome plating onto copper or brass, first plate a layer of white bronze (for guidance on the preparation and use of white bronze plating solution, please see the related pages in this manual). If you are black chrome plating onto nickel or stainless steel, first ActiClean or prepare with MPU, then gold flash (plate a thin layer of gold) and finally black chrome plate. Do not attempt to black chrome plate onto iron or steel as this can only be done successfully by plating it in a tank. A carbon electrode should be used for all black chrome plating.
|Type of problem||Possible reason||What to do|
|No plating taking place||1. Incomplete electrical circuit
2. Surface not clean enough
3. Surface inactive because of thin film of oxidisation which has formed on the underlying nickel layer after cleaning.
|1. Check all electrical connections and clean if necessary. Make sure the swab is fully soaked in solution.
2. Repeat cleaning cycle.
3. Re-electroactivate with ActiClean (taking care that you don’t leave out any areas) or rub with MPU. If the piece you are plating is large (making it likely that the nickel undercoat will be exposed for a length of time), we recommend you gold flash and then black chrome plate to avoid this problem of oxidisation.
|Plating is patchy or not plating at all||Refer to first and third point above||Strip the existing chrome, clean, electro-activate with ActiClean and re-plate. Polish if the underlying layer of nickel is dull.|
|Surface is turning dull, especially on corners or protruding parts||1. Poor cleaning
2. Solution is too fresh or old and stale.
3. Temperature of solution is too low.
|1. Strip the existing chrome, clean, electro-activate with ActiClean and re-plate.
2. Allow the solution to stand for at least 3-4 hours or preferably, overnight. Do not use after 3 days.
3. Make sure the temperature in which you are working is at least 25 degrees Celsius.
|Dark streaks appearing in the plating.||Metallic contamination, most commonly caused by iron from using stainless steel electrode.||Check that the contamination isn’t caused by any other stage of the process and replace the stainless steel electrode with a carbon electrode.|