50090

A good copper electroplating solution for science project

September 23, 2008

I am conducting a science research project inquiring into the relationship between temperature and the amount of copper transfered during the electroplating process. I am in 10th grade Honors class and am looking for a formula for a solution that i can use that does not contain concetrated sulfuric acid. any suggestions would be much appreciated.

John S.
student - Hershey, Pennsylvania, USA

Hi, John. You can use copper sulphate without any sulfuric acid if you wish. It's not ideal, but it will work. See if a local library can get you a copy of the Metal Finishing Guidebook or the Electroplating Engineering Handbook for full details about copper plating. Good luck.

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey

hello, this is a follow-up inquiry. I am in 10th grade honors chemistry class and am doing a science research project. I am testing so see whether temperature affects the amount of copper transfered onto brass cathode. I am setting up my project and am wondering how i could control a constant test group and a higher but sustained temperature. Also, how much can I change the temperature to ensure I am not doing anything unsafe by heating acids.
thank you

John S
student - Hershey, Pennsylvania, USA

Hi, John. You could use an aquarium heater, or pour hot water around your experiment dish in a double-boiler effect. But using ice in the double-boiler may be an easier way to try another temperature.

Regards,

Ted Mooney finishing.com Brick, New Jersey

hello,
I am struggling with my science research project. What could I use as a base metal to plate copper onto if I am using an acid copper solution. My teacher specified i couldnt use brass. I have found conflicting evidence about whether I can use iron, tin, or aluminum. help would be greately appreciated.
thank you

John S
- Hershey, Pennsylvania, USA

Electroplate onto a quarter, John. It's a cupro-nickel alloy. You cannot do scientific work electroplating onto iron, tin, or aluminum because copper will spontaneously deposit onto them, due to their lower nobility, without any electricity applied. Good luck.

Regards,

Ted Mooney finishing.com Brick, New Jersey

Hi,

after taking much info from this site, thought it would be time to give some back. Just tried copper immersion plating on blank steel with household chemicals. The best recipe follows.

Source steel: 4" round disks, drum-deburred, rinsed at the factory. They seem to be oil-free, and corrode quickly if touched by bare fingers. Nails and other hardware which usually rusts works well, too.

Solution: table vinegar (4% acetic acid in water?), the cheapest (and the cleanest) brand - no flavorings, just water and acetic acid. Kosts 40 eurocent per 1.5 liters here in Lidl :) Copper wire from a multi-strand cable. Strip isolation, disperse the braid with your fingers and throw it in acid. Then add a little bit of medicinal (3%) hydrogen peroxide [link is to product info at Amazon] - this will oxidize copper and really speed up the dissolution. You may heat up your solution to some 50-60'C, but even without heating, if you add peroxide, you will see blue tint develop in an hour or two. You may add some table salt, although it seemed to me copper sticks to steel better without.
Alternative solution: 50mM (6gr/liter) CuSO4 in vinegar. Advantage: turns blue instantly :) so you can plate right away, but you will need copper sulfate (which is somewhat poisonous!)

IMPORTANT: when buying vinegar, also buy a steel pan-scraping sponge. When you are done plating, drop the sponge into your solution overnight to remove Cu2+ ions (very bad for the environment) from the vinegar before you dispose of it. Afterwards, you can pour the vinegar down the drain (and trash the sponge).

Plating: 30-60sec will give you a dark copper color finish. Rinse well in distilled water (if available), and DRY QUICKLY! (with a tissue) Your iron is not 100% covered with copper, so it will continue to corrode if wet. You can coat the final product with hairspray to keep it nice for longer.

Extra trick: we first let the kids draw some stuff on the steel with permanent markers which are invisible in daylight and fluoresce under UV (blacklight). Then in daylight they saw their drawing "re-appear" in the copper/vinegar plating bath.

SurfCat at Leiden
- Leiden, Holland