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Heavy deposition 24k gold plating?


#1

Hello All,

My goal is to plate sterling silver rings with Rio Grande’s ‘24ky
heavy deposition bright acid gold’ solution. With 5 failed attempts,
I am still trying to trouble shoot.

The process I used as per each bottle’s instructions:

  1. Clean the piece in the electro cleaner (180 degrees) at 10 volts
    for 60 seconds. The anode was stainless steel and the ‘wire’ holding
    the silver ring was copper.

  2. Rinse with water.

  3. Nickel plate with Rio’s 'bright nickel plating solution (140
    degrees) at 3 volts for 3 mins. Nickel anode.

  4. Rinse with water.

To this point, everything worked well in all 5 tests.

  1. Rio’s 24ky heavy deposition gold plating solution. Instructions
    on the bottle say, stainless steel anode, heat to 100 degrees,
    voltage 1/2 - 3. Time ‘until desired thickness is achieved’ about 100
    microinches are deposited in about 35mins at 3 volts.

I used a stainless steel anode, heated the solution, used a gold
wire to hold the nickel plated sterling ring. I started with 3 volts
and set a timer for 35 mins. Everything looked good for several
mins, a smooth shiny gold plating had consistently covered the
piece. After 15mins, I checked again. It had developed a frosty
thick texture on the ring as well as the gold wire holding it. The
connection between the gold wire and the negative clip had turned
slightly dark. I pulled it out and polished the ring. The plating
seemed to hold up through a light sanding (to level the surface) and
a buffing with tripoli.

Next attempts were with a lower voltage, though it seems they all
get ‘chunky/frosty’ within 15mins.

Questions:

Is this frosty coating normal?

Could this be a result of the bath cooling down in 15mins?

Should I have electro-cleaned again after nickel plating instead of
just rinsing with water?

What ‘wire’ material should I use to hold the piece (negative) for
24ky gold plating?

Any advise would be much appreciated, I have not done much plating
beyond ‘Rhodium’.

It seems like a tricky art

Amy Phillips
www.beegirlmetal.com


#2

Heat must be maintained for the whole process time. If you are going
to be plating for that long you need a thermostatically controlled
heater for your bath.

And yes it is a tricky art and that is why professional platers are
a good idea for anything more than a quick dip in rhodium. Unless you
want to take the time to learn a whole new craft.


#3
Could this be a result of the bath cooling down in 15mins? 

The temperature stated on the plating solution bottle should be held
constant, as James Binnion said.

If you have remaining plating solutions and no way to recover your
cost, then you might as well use them.

I use an electric hotplate with a temerature dial to warm my plating
solutions. Such hotplates need not cost much. I put a 4 quart pot on
it, three quarters full of water, and immerse beakers of plating
solution in that water bath. I regulate the temperature using a dial
thermometer in the water bath. Rio Grande, Otto Frei, Gesswein,
Contenti, and others sell suitable dial thermometers. Allow the
solutions to come up to temperature with the bath.

If you use multiple plating solutions (nickel, gold) at the same
time, and if the required temperatures are substantially different,
use two hotplates and water baths.

The solutions I use require an acid dip between steps. If your
solutions require it, get the acid from your plating chemicals
supplier.

Rather than sanding your plated work, try burnishing in stainless
steel shot instead. A small tumbler and 5 lbs. of shot will get you
started, for small items. If your barrel tumbler is larger, prop up
one end so all the steel falls to the other end rather than spreads
out. It is nice to go first-class with a large tumbler and $500 worth
of shot, but you can start small and add on as you go.

Keep a record of what you do each time and note the results.

Good luck!
Neil A.


#4

James,

And yes it is a tricky art and that is why professional platers
are a good idea for anything more than a quick dip in rhodium.
Unless you want to take the time to learn a whole new craft. 

Thanks for this advice. I didn’t start this thread, but have also
had difficulties with plating. I’ll take your advice, invest my time
elsewhere and quit while I’m behind.

Jamie


#5

Plating is really not that big of a deal. Been doing it for years
with great results.

Part of the secret is getting the items to be plated well finished
and super clean, using a hot ultrasonic, a steamer, and not touching
items to be plated. Keep everything surgically clean. Wear surgical
gloves, avoid plating fumes.

Anything to be plated will need to have the identical finish on the
metal that you want to see when it is plated. Plating won’t polish
anything brighter than it already is.

Rio Grande makes a “Heavy Deposition” gold plating solution, which
lets you just plate and plate a heavier and heavier layer of gold on
the object you’re plating. Stays bright, and won’t “brown out”. I
love this solution. Copper plating is necessary if your plating
surface is “iffy” and may not take plating easily. After the copper
plating, which goes on easy to most metals, you’ll want to put a
nickel plating, which seals the surface of the metal beneath before
the gold goes on. If you’re plating over sterling, for instance,
you’ll need to prevent the copper molecules (tarnish) from migrating
through the gold plating and ruining the plated finish. The nickel
plating prevents any migration through this nickel barrier, and keeps
the gold plating looking good.

Just remember, except for rhodium, which is one tough surface, gold
and silver plated surfaces are pretty vulnerable to wear. Rio Grande
has a wonderful consumer help service, and they can answer specific
plating questions easily.

Jay Whaley
Whaley Studios