gold electroplating on sliver

[Julie Harnois New User Find all posts View Profile Close Julie Harnois]

Hello people!
I am a super amateur I might be doing everything wrong so let me know

I want to plate a musical instrument mouthpiece (trombone trumpet or horn)
A trombone mouthpiece is about 7 in square, a trumpet and horn about 4 in square
To gold plate I am using a kind of adaptor that I found working for that with stainless electrode
4 amps
5 volts
Temperature is about 30 sec in the microwave for 4 oz of liquid gold solution
Duration of plating about 1 minute
before electroplating I clean the silver with a silver polish, then dish soap, then boiling water

It works but the plating stay for about 1 month,
as the mouthpiece is placed on the lips for about 5hr a day everyday
I cannot use any hard chemical as the mouthpiece have a direct contact with the skin

is there something I can do so that my plating will last longer?
maybe some kind of electro cleaning is necessary?
longer plating time?
temperature?

I do it because I have a silver allergy and for some of my friends in the same situation and this gold plating remove all the problem i suffer from the silver.
If somebody could suggest me ideas I am open to suggestions!

Julie

[gsw3 Amateur Metal Finisher Find all posts View Profile Close gsw3]

Re: gold electroplating on sliver

I have never plated gold directly over silver (I always do a nickel strike coat first); however, assuming you are using Caswell’s gold plating solution try the following:

1. Cleaning:
(A) Be certain that the silver polish you are using does not contain any silicone in it’s formulation because it will be all but impossible to get the silicone out of the pores of the metal and the plating will not adhere to the base metal. I found out the hard way, not a good thing.
(B) As far as using dish soap for cleaning, be sure that it does not contain any lotions (aloe, etc) as this will also cause the plating to fail. I was using Dawn dishwashing detergent (The blue stuff) with good results on the water break test the water must sheet off the part when rinsing, not bead up). I have since switched to another type of cleaner (Awesome).

2. Pickling:
I noticed in your post that you are not pickling the part (acid dipping) prior to plating. I can’t say for sure exactly what acid to use on silver (I always use diluted sulfuric acid (battery acid)) and a distilled water rinse when plating nickel, copper and Copy Chrome on to brass and steel prior to the part going into the solution. You might try vinegar since it is readily available and mild and see if that helps. Be sure and rinse the part in distilled water after the acid dip. I rinse in distilled water then use a spray bottle filled with distilled water and spray the part down to be sure all the acid is removed.

3. Part square inch calculation:
It seems like your mouth pieces should figure out to around 2 to 3 square inches, not the 4 to 7 you stated in your post. 3.1416 times the diameter times the height of mouthpiece times 2 should get you close to the actual square inch area. I did the last “times 2” in the formula to get the inside area of the mouthpiece. Not much plating will get into the inside because of anode shadow.

3. Voltage/Amperage:
Your voltage and amperage is way off. Try 2 volts @ 50 milliamps per square inch of part area (1000 milliamps = 1 amp). Also, are you using a constant current power supply? It is very important that you have the correct amperage or no plating will result or you could burn the part. Also, be sure and go in electrically connected (power on the part) prior to putting the part into the solution.

5. Solution Volume, Temperature and Anode:
(A) you say you are using just 4 ounces of solution. Here may be another issue. When you use a stainless steel anode (verses a gold anode) when plating you are drawing out the gold from the solution (verses using a gold anode the gold comes from the anode not the solution) so you will be depleting the amount of gold rapidly from 4 ounces of solution. Try using the entire quart in a larger container. There is no reason to discard the solution (as long as you don’t contaminate it). Just pour it all back in the container for future plating jobs.
(B) Instead of guessing at the solution temperature, actually measure the temperature, it should be 140 degrees F.

6. Agitation/Anode placement and size:
(A) It is important that the solution has some agitation/movement during the plating. I use air and large bubbling (not an air stone which results in fine bubbles sticking to the part). For your application a small fish tank air pump (Caswell has them) with just an open ended air line at the bottom of your plating tank bubbling on the part should suffice.
(B) Place anodes on both sides of the tank and the anode square inch area should be twice the part square inch area.
(C) Part rotation; I devised a device to rotate the parts in the plating solution to insure the plating is even. You can do this by simply rotating the part (or the anodes) every couple of minutes to be sure the anodes don‘t build up the plating in the area they are facing the part.
(D) Part hanging wire; use only pure copper wire to hang your parts. Also be certain that only the stainless steel anodes are in the solution, not any other metal (like an alligator clip attached to the anodes below the solution level).

7. Plating Time:
You state a 1 minute plating time. This is just not enough time. 1 minute of plating will give you just a vapor thickness of gold. You need the following times to build up the gold plating to the stated thickness listed below: For reference, a human hair is .0015” thick (it would take 90 minutes of plating time to get a human hair thickness of gold).

1.2 minutes = .00002” thickness
1.8 minutes = .00003” thickness
3.0 minutes = .00005” thickness
6.0 minutes = .00010” thickness
12.0 minutes = .00020” thickness
18.0 minutes = .00030” thickness
30.0 minutes = .00050” thickness
90.0 minutes = .00150” thickness

I have been plating small parts for over 13 years.. See some of my work on the opening pictures on Caswell’s nickel and CopyChrome ads.

Good luck, tell me if any of this helped you.

[Julie Harnois New User Find all posts View Profile Close Julie Harnois]

Re: gold electroplating on sliver

Wow Thanks!
I will try it and let you know
so much details
thanks a lot!!

[ZingZong707 New User Find all posts View Profile Close ZingZong707]

Re: gold electroplating on sliver

Thank you very much for this valuable contribution and informatic.Keep updating us.*Great job

[Linda E. New User Find all posts View Profile Close Linda E.]

Re: gold electroplating on sliver

I want to add goldplate to small sterling silver jewelry findings. Has anyone tried this with the Plug'n'Plate kit, and does it work well? If so, any tips?

[Julie Harnois New User Find all posts View Profile Close Julie Harnois]

Re: gold electroplating on sliver

Yeah it work well! if you touch it everyday because you wear the jewellery the plating might go off after 2-3 months. But you can still do it again, It take 5 minute to do