How to Make Aluminum Black
by Brandy Alexander
Anodizing aluminum black may be easier than you think. With a few commonly found materials from your local hardware store, you can transform aluminum from a dull gray to a brilliant and impressive black. Anodizing makes the outer surface of aluminum much stronger and prevents oxidization. It is also the only way to permanently color aluminum.
Step 1
Clean the piece of aluminum you wish to anodize as thoroughly as possible. Use dish washing liquid and water for this task. After washing, degrease the aluminum using some degreasing cleaner.
Step 2
Desmut the piece of aluminum by submerging it in desmut liquid for about 2 minutes. Use one of the polythene tubs for this step. Warming the solution to about 140 degrees Fahrenheit will improve the desmut results.
Step 3
Mix one part sulfuric acid with one part distilled water in the other tub. Add the water first, then slowly add the acid. You should mix enough to fully submerge the piece you wish to anodize.
Step 4
Attach the negative cathode from the power supply to an aluminum plate. Submerge the plate into the acid solution.
Step 5
Connect the positive lead from the power supply to the aluminum piece you want to anodize using a length of aluminum wire. Place the piece of aluminum into the acid bath solution.
Step 6
Turn on the power supply to 12 volts DC at two amps. Monitor the cathodes for bubbles forming in the acid solution. This will tell you that current is flowing.
Step 7
Remove the piece of aluminum when you notice no more bubbles forming on the cathodes.
Step 8
Mix 4 tbsp. of black anodizing dye with 2 quarts of distilled water. Submerse the piece of aluminum in the dye solution for 15 minutes. Heating the dye solution to around 100 degrees Fahrenheit will help to make the dye adhere better.
Step 9
Remove the piece of aluminum from the dye solution. Seal the aluminum's surface by boiling it in pure distilled water for about 30 minutes. Remove the item from the water after the 30 minutes have elapsed.
References
Tips
- Changing the amount of time the aluminum sits in both the acid bath and the dye as well as changing temperatures will enable you to slightly modify the depth of color.
Things You'll Need
- 2 polythene tubs, 10 gallons each
- Dish washing liquid
- Water
- Degreaser
- Desmut liquid
- Sulfuric acid
- Distilled water
- DC power supply
- Aluminum sheet and welding wire
- Aluminum plate (cathode)
- 2 gallon pot
- Black anodizing dye
- Safety gear
- Baking soda
Warnings
- Always wear appropriate eye, hand, skin and body protection when anodizing and working with acid.
- Always dispose of acids and dyes in the appropriate manner; contact your local waste management company for details.
- Keep some baking soda handy to use to neutralize any spilled acid.
Writer Bio
Brandy Alexander began writing professionally in 1993. She has years of experience as a professional of the English language employed with the "Cape Times" and "The Mercury." Alexander holds a master's degree in English literature from Stellenbosch University in South Africa.
