Anodes are performed using an acid to form a corrosion and wear resistant coating on the metal surface. The anode process will also change the crystalline structure on the surface of the substance (as in aluminum alloys), allowing you to color the metal using a bright color. Doing an anode yourself at home can be very useful for some projects, such as securing a family heirloom metal object or ancient jewellery. You can also use it to do experiments at home with older children. Don't forget to take precautions regarding caustic materials (flammable, rust and crumble), such as sulfuric acid and alkaline solutions, when you anodize aluminum at home. These materials can cause chemical burns if not handled properly.
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Part 1 of 4: Preparing the Ingredients
Step 1. Purchase some standard aluminum alloy metal
Anodes do well on aluminum. So, you can do it yourself at home if you are careful. Start with small pieces of aluminum as a first step to soaking in the acid solution.
- You can buy small pieces of aluminum for this project at a hardware store or online, for a relatively low price.
- In this process, the piece of aluminum to be anode functions as the anode (the part that is positively charged).
Step 2. Buy a thick plastic tub in which to soak the metal
Choose a very hard and strong plastic material. The size of the tub to use will depend on the metal being handled, but make sure it is large enough to accommodate the metal and aluminum, and that there is room left for the soaking liquid.
Step 3. Buy clothes dye at the grocery store
When anode, you can dye the metal almost any color using regular fabric dye. This process is also used by Apple when coloring their iPods.
You can also use special anode dye for better results
Step 4. Purchase the materials needed to perform the anode
You will need some special tools to do the anode at home. Most of this equipment can be found at hardware or hardware stores. Some of the items needed include:
- Degreaser (fat and oil removal product)
- 2 lead cathodes long enough to hang over a plastic case
- Aluminum cable reel
- Distilled water in sufficient quantity to fill a plastic tub.
- Baking soda
- Rubber gloves
Step 5. Look for shops to buy hard-to-find materials
To perform an anode, you will need a few liters of sulfuric acid (battery acid), an alkaline solution and a constant power supply with a voltage of at least 20 volts. Maybe you will have trouble getting battery acid. However, try looking for it at an auto supply store. A large battery charger can also be used as a constant power supply.
Part 2 of 4: Cleaning Aluminum
Step 1. Wash the metal using soap and water
Clean dirt and debris to facilitate the anode process, and minimize the possibility of failure when running the process. Wash the metal you want to anodize with a mild detergent and warm water. Next, dry with a clean tissue or cloth.
Step 2. Use a cloth to apply the degreaser
Follow the directions on the product packaging for using a degreaser to remove any oil that is still adhering to the metal. Wipe the metal if necessary, and make sure that no product remains on the metal before you move on to the next step.
Step 3. Dilute the lye with water to make a soaking solution
Use a small plastic tub to mix 3 tbsp. (50 ml) lye with 4 liters of distilled water. While wearing rubber gloves, dip the object you want to anodize into the solution. Let it soak for about 3 minutes before you take it out and clean it with warm water.
- The alkaline solution will remove the anode that is already on the metal surface. After the anode layer is removed, the metal surface will be easily wetted with water, and will not form water droplets on it.
- Wear rubber gloves when you handle alkaline solutions.
- Do not use spoons or measuring cups used for food. The materials used to carry out this process are toxic.
Part 3 of 4: Preparing the Anode Tub
Step 1. Place the plastic tub in a well-ventilated space
This tub should be placed in a location away from objects that could harm the anode process. Place the plastic tub on top of a wooden plank and/or heavy cloth to contain any spilled liquid. The ideal place is a garage or shed that has its doors and windows open.
For best results, we recommend doing this process when the room temperature reaches 21-22 °C
Step 2. Prepare the power supply
Place the power supply on top of a non-combustible object, such as concrete. Use a multimeter (available at auto supply stores) to ensure that the battery you are using can function consistently.
- Connect the positive wire from the battery charger or rectifier to the wire to be attached to the aluminum.
- Connect the negative lead from the battery charger to the aluminum wire connected to the 2 lead cathodes.
Step 3. Tie one end of a long aluminum wire to the anode (aluminum object)
For this purpose, you can use a 12 gauge aluminum cable. Twist or connect the wires in a hidden area. For example, if you anodize a key, wrap the cord around the joint between the blade and the back of the key.
- Areas that are wrapped in wires will not be anodized.
- For a consistent flow of electricity, wrap the wire tightly.
Step 4. Wrap the center of the wire onto a small wooden plank
The wooden planks should be longer than the width of the plastic tub. This is to make it easier for you to lift the aluminum when the process is complete later. Once wrapped around the wooden board, make sure that there are still remaining wires to connect to the power supply.
Check the wooden plank to see if the aluminum object is submerged in the acid solution, but not touching the bottom of the plastic tub
Step 5. Place lead cathodes on each side of the plastic tub
Run the aluminum wire between the 2 cathodes and connect them to the wooden board. You must attach the negative part of the power supply to this cable.
Make sure the wires connected to the aluminum object do not come into contact with the lead cathode
Step 6. Make a mixture of distilled water and battery acid in a plastic bath in equal proportions
The amount required depends on the size of the aluminum to be anodized. The water should be sufficient to completely submerge the metal. Be careful not to spill the mixture when you stir it.
- Put on a mask or respirator before you handle acid. Increase the ventilation of the room by turning on the fan.
- Be sure to always pour water first before adding the acid.
- If any acid is spilled, immediately sprinkle baking soda on top.
Step 7. Connect the aluminum wire to the power supply
The wire connected to the aluminum object must be connected to the positive terminal on the power supply. The wire coming from the lead cathode must be connected to the negative terminal on the power supply.
Before turning on the power supply, check around the plastic tub to make sure no liquid has been spilled. Double check that the power source is securely connected, and that all parts of your skin are covered
Part 4 of 4: Anodizing and Dyeing Metals
Step 1. Turn on the power source
Once turned on, slowly increase the power until it reaches the ideal amperage (electric current). The general rule is 12 amperes for every 9 square cm of metal material.
Increasing power too quickly or using too much power can burn aluminum wires
Step 2. Keep the power supply constant within 45 minutes
Small oxidation bubbles will begin to form on the surface of the aluminum. The color of the aluminum object will also start to turn brown, then yellow.
If no bubbles form after the power supply is turned on for about 30 seconds, turn off the power supply and check the connection. This usually indicates that the power supply is not properly connected
Step 3. Mix the dye during the anode process
If you want to color the aluminum metal, prepare the dye so that it is hot and ready to use when the aluminum is removed from the plastic tub later. Each dye has different requirements. So, prepare the dye according to the instructions given on the packaging.
- Heating the dye will increase the amount of pigment that can be absorbed by the aluminum metal. However, do not heat the dye above 50 °C.
- The pot can be damaged if it is exposed to the dye. So, use old pots that are not used for cooking food.
Step 4. Turn off the power supply when 45 minutes have elapsed
After the anode process in the plastic tub is complete, turn off the power supply before you remove the metal. Carefully remove the aluminum metal, then wash it using distilled water.
- Do this quickly if you want to color the aluminum.
- Always wear safety gloves when picking up and washing aluminum.
Step 5. Put the aluminum in the heated dye bath
Let the aluminum soak in the dye for about 15 minutes. If you only want to color certain parts of the aluminum (such as only the back of the key), wrap the aluminum wire around the area you don't want to dye. Use this part as a handle when you dip the aluminum in the dye.
If you don't want to stain the aluminum, boil the metal immediately in distilled water for about 30 minutes
Step 6. Boil distilled water on a hot plate (the hot plate used in the laboratory)
You must provide enough water to completely submerge the aluminum. Once the aluminum is finished coloring, remove it from the coloring pan and place it in the boiling water for about 30 minutes.
Step 7. Carefully remove the still hot aluminum, then let it dry
Place the stained aluminum on a clean washcloth or towel and let it cool before you handle it. When it's cold, you'll need to seal the surface tightly.
Warning
- The materials used in this project can be hazardous if spilled or swallowed. Keep pets and children away from your work area. Make sure you always wear thick clothing, protective eyewear, and gloves.
- Never pour water on an acidic solution. This can cause it to overflow and explode. This reaction occurs due to the heat generated, and can result in acid burns.
