Safer electroplating solution 2

Ok, the new (now pure) Trisodium Phosphate came in. Time for a new, slightly more careful, set of experiments - This time with pictures.

Standard solution composition:

32g Oxalic Acid

10g Trisodium Phosphate

4g Ammonium Sulphate

950 mL Water from water filter.


Experiment 1:

Temp 70C

Target CrV steel wrench

Anode: Copper

Constant current set to 1A

Plated area guesstimate: 5 in^2

Time log (HH:MM):

09:30: Start

09:35: Nice copper layer already. Decorative quality

09:45: Sparkling noises around copper anode. Particles floating in solution; starting to stick on wrench. Removing sample.


Wow! Decorative and strongly adherent copper plating in only 15 mins.

Experiment 2:

Continue to use the same solution to plate a stainless steel spoon.

Area estimate for the spoon: 8 In^2

1A at 20V. Result: Strongly adherent copper plating. At the concave of the spoon and the area opposite of where the stirring directed the solution there was little to no plating. Maybe lower current would even that out. Or maybe a greater distance from the anode. The plating was dull but buffed up to a nice shine with a little rubbing. I put both black and white backgrounds in the photo to give a better sense of color.

Experiment 3:

Try to copper plate a brass rod using the existing solution.

10:11: Start. 1A. Area estimate: 1.6 in^2

10:21: Stop. Matte plating. Strongly adherent. Cleans up nicely with a little buffing using stainless steel wool.

Experiment 4:

Use existing solution to plate copper onto aluminum foil.

Area estimate 2 in^2

Current: 1A

Result: Matte deposit with no adherence at all. The deposit can be rubbed off with ease.

Experiment 5:

The patent describes a process to clean all the anode metal ions out of the solution by reversing the current and using a carbon anode.

10:39 : Start. Current 1A. Solution color: milky blue.

11:34 : increase current to 2A. Color still milky blue but lighter.

12:06 : increase current to 3A. Color now transparent blue.

12:30 : almost clear.

12:50 : stop. clear color. Take apart setup. Copper electrode looks cruddy. Upon closer inspection the solution was not completely clear.

18:30 : Start. Cleaned copper anode. Continue reverse operation to get solution completely clear

19:30 : Clear. Stop

Experiment 6:

One of the most interesting aspects of this solution is its purported ability to be reused for a different anode material. So after removing the copper ions with the reverse plating I want to try to use the very same bath for nickel plating.

Anode material: Nickel

Cathode: copper plated wrench from earlier experiment. submerged below the original plating area to see if copper and/or CrV steel can be plated.

Result: black coating on entire submerged area. Can be rubbed off easily to reveal nickel on the area that was copper plated. No nickel plating on the CrV steel.

Experiment 7:

Nickel plate the brass rod that was copper plated in experiment 3.

Rod submerged 3" deep. Approximate area 2 in^2

Current 0.1A

20:02 : start.

21:00 : stop. Result: both the copper and the brass got plated with nickel. The plating was black but could be cleaned up with stainless steel wool. The plating was very thin. The underlying metal is visible. Longer plating time and maybe lower current seems prudent.

Experiment 8:

I am using the spoon from experiment 2 as the cathode and submerging enough that both copper and stainless steel are plated on to.

Current: 0.08A

Area estimate: 6 in^2

06:00 : start.

07:00 : nice coverage on both the copper and the stainless steel. Have to interrupt. Taking spoon out of solution. plating looks slightly dark.

08:00 : continue

08:30 : second interruption. Spoon out again.

10:00 : continue

12:30 : stop. Result: Nice clean deposit.

It is a little difficult to see the difference between the nickel and the stainless so I wanted to see if there was copper underneath just to be sure. I took some fine sand paper and slowly took the nickel down to look for the copper. Sure enough it is there.

It is not clear whether we have nickel plated onto the stainless..

Success!! The problems in the original series of experiment were truly caused by the contaminated TSP. Nickel plating did not work at all there.

Experiment 9:

The patent claims the ability to plate alloys such as brass and Monel. Using a freshly made solution to test depositing brass onto steel.

Target: Steel parallel

Area: approximately 6 in^2

Current: 0.5 A

Temp: 64 C

Result: Black deposit. Stainless steel wool reveals some non-strongly adherent copper.

Experiment 10 :

Repeat experiment 9 with lower current density.

Result: copper-black deposit; Precipitate in solution

Experiment 11:

Use the same solution to try to plate brass onto the nickel plated stainless steel spoon from experiment 8.

18:06 : start. Current 0.1A

18:08 : current has dropped to 0.03A. Looks like a copper deposit is forming.

18:55 : stop.

Result: There was a dark brown chocolate color film up to the level of immersion. This could be removed with stainless steel wool leaving only the copper layer onto which the nickel had been plated. Looks like we took the nickel clean off...

Experiment 12:

Hard chrome plating. This whole series of experiments was started with the question of whether this solution was able to do hard chrome plating and the bad-TSP solution could not. So lets give this another try.

Fresh solution.

Current: 0.1A

Target: partially copper plated stainless steel spoon.

Temperature: 70 C

Anode: 99.9% pure chrome slug.

07:08 : start

08:10 : solution is light blue

09:00 : solution is blue green

10:30 : no sign of deposit. Increase current to 0.4A

10:45 : solution deep green-blue-black

11:40 : stop. No visible deposit of any sort.

Experiment 13:

Use existing solution from experiment 12 and just change out targets.

New target: partially nickel plated CrV steel wrench.

11:43 : start. Current 0.04A

12:05 : gotta stop. No sign of deposit.