On February 14, 2018, nine copper strip tests were made for the upcoming President's Day weekend trip to Texas for a field test. This is a new procedure that is largely based off the methods detailed in Demirkan et al. (1) This method uses a variety of washes that remove hydrocarbons and oxides from unpolished copper sheets so that they may corrode more evenly. The reasons for switching to this method from the copper rod method can be reviewed in this note. Additionally, a video has been created demonstrating this method. Please follow this link to the video for visual guidance in this process. Below are the materials and procedure for testing method preparation.
- Integrity Beads Copper 24 Gauge Sheet - 6" x 6"
- 70% isopropyl alcohol
- White vinegar
- Distilled water
- KimTech wipes
- Utility knife
- Ultra-fine sharpie
- Latex gloves (DO NOT use vinyl)
- Plastic bags
- Mounting platform (I used a radiello badge, but use whatever you have on hand.)
- Cutting board with soft padding (clean scrap towel, paper towel, etc.)**
Kim Tech Wipes and Latex Gloves
Solvents (Distilled Water, Acetone, 70% Isopropyl, and White Vinegar)
-Cutting the sheets-
- Designate a large area for your workspace. There are going to be many solvents and materials to go through in this process, so a lot of space is advisable. Organize your materials in a way that makes sense to you.
- Put on LATEX gloves. It is really important that you use latex. You will be handling acetone, which dissolves vinyl gloves
- Remove the copper sheet from the sealed Integrity Beads baggie
- Choose your experimental side (corrosion side) and then your cutting side
- Experimental side should have fewer cuts, scrapes, and other surface abrasions
- Place the experimental side face down on the soft surface on your cutting board. The soft surface is to ensure the copper sheet doesn't scratch while cutting and handling.
- Mark with your sharpie and measure with your ruler on the cutting side where you plan to cut
- I marked two parallel edges of the sheet with 2-inch marks, then marked the other two parallel edges with 1-inch marks, and then connected them. This created a grid of eighteen 2" x 1" rectangle strips. Please feel free to cut the copper sheet in whatever way you wish to do it. My method is not critical for the success of this test.
- Cut the copper sheet along the lines using the utility knife with extreme caution since it is really sharp. This process will take a lot of pressure on the sheet and will require repetitive cuts over the same line.
- The utility knife will not be able to cut all the way through. Make about 10-12 cuts along the same line until it is fairly deep. Pick up the sheet with gloves on and gently and slightly bend one way and then the other way. Repeat this over and over again until the copper sheers off.
- Do this for all lines.
-Preparing your mounting platforms-
- Remove your gloves
- Prepare the velcro
- I cut my velcro into small pieces (approx 0.5 x 0.5 inches) and then stuck them to the cutting side of the copper sheet before solvent treatment
- Leave the other side of the velcro sticker on for now
-Washing, polishing, and mounting the strips-
- Apply acetone to a KimTech wipe and then wipe down all of the experimental sides of the copper strips (the side without the velcro attached). Feel free to trash the wipe if it gets ripped all over and start with a fresh one.
- Apply some isopropyl alcohol to a KimTech Wipe and then wipe down all of the strips on the experimental side again. These first two washes removes hydrocarbons from the surface
- Wash off these surfaces with distilled water. Don't worry about drying off the strips for now since there is one more wash.
- Apply some vinegar to a KimTech wipe and then wipe down the same surface This removes oxides from the copper surface. I used vinegar instead of nitric acid that Demirkan et al. used because it is more readily available and does a similar task.
- Finish up the washes with a good rinse with the distilled water
- I gently patted down my copper strips with a KimTech wipe
- Mount the strips to your mounting surface
- I used a radiello support plate for this experiment for easy hanging in the field.
- Last, place your final product into a baggie so that they are not exposed to outside air.
- Demirkan K, Derkits Jr. GE, Fleming DA, et al. Corrosion of Cu under highly corrosive
environments. J. Electrochem. Soc. 2010; 157(1): C30-C35. doi: 10.1149/1.3258288****