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Rhodium plating problems


#1

Hi all of there, I was faced some rhodium plating problems(im new in plating),i was work on gold jewelry,but i alway cant reach the ideal
result ,may be the rhodium solution was not reach to the ideal
temperature or the jewelry was not clean enought ! i was tried to clean
the jewelry with asid(10%asid with 90%water),i tried once,is that
right? i will appriate if somebody who can share their experience or
giving me some advice. i would like to know what is the ideal
temperature of the rhodium solution, what is the ideal method for
clean up the jewelry & what is the ideal power volt to be set to.

besides,someone who can tell me where can i find a jewelry plating
guide book. (except RioGrande,there is no stock)

Thanks all of you.

Paul


#2

Paul, Sounds like cleanliness is the problem. I always rhodium plate
at room temp and get good results. Try using an electrocleaner
solution on the item before rhodium plating. Rinse with distilled
water and be sure not to get any fingerprints (oil) on it prior to
plating. You didn’t specify what the item that you are plating is
made from but, if you are plating silver or base metals; you must
first nickle plate it before rhodium plating. Otherwise, you will
contaminate the solution rendering it useless. Good luck! Ken


#3

There are 2 baths for rhodium plating: the degrease and the rhodium.
Degrease temp is 60 to 80 Celsius 4 volts, rhodium is 35 Celsius 4
volts. Preparing rhodium bath for first use is important: Depending on
the water/rhodium ratio, first boil the water, then as soon as it
starts boiling turn off the heat and pour the rhodium solution quickly
into the water. let it cool. Plating: first clean the jewelry with
ultrasonic , steam or a good soap and water. rinse, rinse, rinse. then
degrease for 1 minute at 60 to 80 Celsius. rinse, rinse, rinse.
extremely important to rinse under running water, not one drop of
degrease should contaminate the rhodium bath. never touch the jewelry
with your hand after degreasing. then rhodium plate for 1 minute at 35
Celsius. rinse and that’s it. the above goes for white metal plating.
if plating yellow gold, first nickel plate the jewelry then proceed as
described. Nickel plate is done at room temperature for 1 minute.

Fady Sawaya
@Artemis


#4

Paul, I plate pieces at room temperature.I use a glass coffee cup.In
the cup I have a platinized titanium annode wich I believe I purchased
from rio grande. Before that I used a stainless steel knife blade that
I bought at the dollar store.I bought a used rectifier that originally
came from a University of Colorado engineering lab for 75 bucks.It
only goes up to 12 volts D.C. wich works fine for what I use it for.I
have two radio shack aligator clips and some 8 or 12 guage sheilded
copper wire connecting them to the rectifier.I make a small hook out
of ss wire solder which is clipped in the alligator clip to hold say
a ring.The annode is hooked to the positive side of the rectifier and
the wire holding your piece is on the negative end.I usally crank the
voltage up all the way and adjust the amps.I don’t really use the
meters any more I just look at the piece and adjust the knob on the
rectifier until the ring is covered in bubbles that are rolling of the
piece if they are rolling of the piece too violently you will "burn"
the piece wich means it is plating with too much current.You can see
the process occuring.Take a piece of scrap and experiment until you
achieve the desired results.I have found that each piece varies when
it comes to plating.After I have plated the piece I rinse it in a
beaker of clean cold water.If you have a piece that is yellow gold
with a white pave plate or just two tone I use finger nail polish as a
mask.It will not plate where you paint it.After it is plated I put the
piece in a metal container full of accetone which rests at just the
right level on the rack of my ultrasonics to not get water in it.The
ultrasonic and the accetone blast the nail polish out of the
piece.Then I put the piece into the ultrasonic and steam it.Before I
plate a piece I prep it by buffing any old rhodium off and ultrasonic
and steam the piece.I don’t touch the piece from the steamer into the
plating bath.Fingerprints and grease don’t get along with the plating
process.Oh by the way make sure you are doing this in a well
ventilated area.Don’t put your head over your beaker or cup to see
what is going on.Never ever ever get acids of ANY kind near or into
any cyanide solutions as it WILL kill you.The best rule of thumb is to
keep them on seperate sides of your studio in locked cabinets.You
should avoid getting large quantities of solution in cuts as you can
become unconcious.This is common sense but I will say it anyway keep
your plating solutions locked up and out of reach of children and
pets.If you are doing large quantities of plating study material
safety data sheets and medical literature on it.This stuff demands
respect.

Regards
J Morley


#5

Hello J. Morley, Try using a magic marker to mask off what you do not
want plated. It is a bit faster than fingernail polish (which I used
for about 35 years). Have fun. Tom Arnold


#6

Hi Morley, I will very appriciated upon your advice & opinion,so what
is the voltage & time you always maintain ?(i mean how long you put
the pieces into rhodium solution). you said that you put the solution
in a glass,so ,what is the ratio between rhodium & water you alway use
to get the good result?

finally,i would like to say once again,Thank you! & i hope to have
more opinion from you.

Regards,
Paul


#7

Hi Fady, First of all,i would like to thank you for your useful
opinion & advice,i really appriciated. could i ask for what is the
ideal ratio of water/rhodium,i used 25ml rhodium into 450ml distilled
water,is this correct?

so, that is the formula you always use for your rhodium plating which
you told me yesterday(35c + 1 min + 4volts),i will try this tomorrow.(35c will no smook come up?)

i had saw somebody use (60-80`c+10sec+12volt) to plate the jewelry &
the resulted was no bad,do you try this before besides your formula?

i hope to have more opinion from you,

Thanks,
Paul


#8

Hi Ken, Anyway,thanks for your helped & adviced to solve my problem,i
really very appriated. you mean in room temperature is around 35.c, do
you? mmm…now,i knew what is my mistake,i always heat the solution
untill the smooth came up,i guess that too hot,right?and my voltage
alway set to 10-12volts.oh my god ! i had doing a big mistake. yes,some
of my pieces are copper jewelry but it was already nickel & gold
plated ,and my process is making to 2 tone colour with rhodium,do you
even use asid+water to clean up any pieces? or do you even heard
somebody using this method?that is a stupid job,do i ?

i had one experience with my work,when i first put the piece into the
solution(about 20 sec) but the area which i wish to plate cant all completely plate,that is some place white( grey white but not blight write,hi..that is not i want ) & some place still yellow,and i put in again & again(2-3 times), finally,that yellow place become black(burned !),so what is the problem? i guess that is cleanliness problem,dont
you?

Paul


#9

I use rhodium as a liquid straight out of the bottle.The glass
I use holds about a cup of solution.No water.Then when Iam done
I return it into the bottle using a funnel.The lenght of time
varies but for a ladies ring about a minute to a minute and a
half.Again if you experiment with a scrap piece of metal a good
way to check your thickness is to plate a piece of scrap and
then buff it off.I have found that a minute gives me a good
covering that is hard to buff off after a minute.Also your
rhodium will lose its strength as you use it you are depleting
the metal out of solution. Regards J Morley Coyote Ridge Studio


#10
          Hi Fady, First of all,i would like to thank you for your
      useful opinion & advice,i really appriciated. could i ask for
      what is the ideal ratio of water/rhodium,i used 25ml rhodium
      into 450ml distilled water,is this correct? 
  I use the German brand "degussa". it's a 100ml bottle to be
  added to 1 liter of water. 
          so, that is the formula you always use for your rhodium
      plating which you told me yesterday(35`c + 1 min + 4volts),i
      will try this tomorrow.(35`c will no smook come up?) 
  35 Celsius will not smoke up. sometimes when I'm in a hurry I
  keep the bath to room temperature (25 c) and it works well. 
          i had saw somebody use (60-80`c+10sec+12volt) to plate
      the jewelry & the resulted was no bad,do you try this before
      besides your formula? 
  Maybe the rhodium bath is of another concentration in order to
  heat it to 60 or 80. I'll try it anyway. 

Fady Sawaya
artemis@inco.com.lb


#11

Wow Paul! 10 to 12 volts is WAY too much voltage for rhodium.
Sorry I didn’t specify that in the first post… I use 2 to 3
volts max; and only plate for a few seconds. It shouldn’t take
any longer than that. If you are getting bubbles from the item
you are plating, then you are using too much voltage. The dull
black areas are probably from either too much voltage or the
item is dirty. If you have access to an ultrasonic and steam
cleaner, use them before using an electrocleaner solution. The
electrocleaner I use is not acid based but is an alkali. Acids
wont remove any oil or grease. Also, make sure you are using the
proper anode. Platinum, platinized titanium, or nickle. As far as
the temperature goes, I forgot the conversion factor from F to
C, but 35 degrees C sounds right…I just use the solution
straight out of the bottle whatever the temperature is. I only
rhodium plate occasionally. I am sure someone else on the forum
has much more experience at it than I do, But I seem to get good
results. Good luck! Ken


#12

Hi all, A quick note on Rhodium plating problems…

  First it's best to follow the manufacturer's instructions
  exactly for any plating product.  Most Rhodium baths are used
  at room temperature.  Heating them, especially to boiling, can
  ruin them permanently.  

  Bad overall color can occur if the bath is too hot or too cold
  - or if it was severely overheated at one point.  Even when
  allowed to cool to room temperature again, it may never again
  plate a good white color.  If that happens, you have to start
  over with a new bath. 

  Brown spots or discoloration can be caused by a contaminated
  bath.  When the bath is not in use, remove the anode (rinse in
  distilled water and put aside in a clean place), cover the bath
  so nothing extraneous can get into it.  

  Generally speaking: if the plating does not adhere to the item
  being plated, the item has not been cleaned well enough.  It's
  important to degrease the item - an ultrasonic works fine for
  this.  Steam cleaning is a good next step.  Electrocleaning is
  ideal. 

  If you get brown or black spots, it's usually because the
  voltage is too high.  You can verify this as the cause if the
  dark spot is concentrated around the contact point to the lead
  wire.  Never turn the power up so high that you see bubbles
  form on the item.  That's a sure indication of too much juice
  (electricity) - it's just not necessary and can cause problems. 

  Splotchy or cloudy looking areas are most often caused by
  chlorine contamination.   Rinse your item in distilled water
  (not tap water) before Rhodium plating.  The dragout of tap
  water into the Rhodium bath introduces chlorine into the bath. 
  Over time the chlorine 'eats' the Rhodium and results in that
  cloudly splotchy plate. 

  Keep a careful eye on the bath level.  (I plate in a beaker and
  when using a new bath, I put a rubber band around the outside
  of the beaker so I know the correct level.)  Rhodium baths need
  to be replenished at some point in their life.  As they
  evaporate you can add distilled water back up to the line (or
  rubber band in my case :).  Also as the bath is used, the
  chemistry changes.  This affects the results of course.  At the
  very least, you will notice that the piece is not plating as
  fast and just seems "weak".  Follow manufacturer's instructions
  carefully for replenishing. 

  Lastly be sure your Rhodium is sulfate type.  That type gives
  the whitest color. 

Best Regards,

Elaine Corwin
GESSWEIN CO INC USA
Tel: 1-800-544-2043, ext. 287
also 203-366-5400
Fax: 203-335-0300


#13

Hi All There, Thanks for your all helpful suggestions & opinions,especially i would
like to thanks to Ken, J.Morley, Elaine Corwin, Duane Pebworth, Faby Sawaya … I
will really appriciated for yours kindness to answered & solved my plating
ploblems,i`m very happy because i was learned a lot of plating technique from
yours.

at here i still have some questions,what is the meaning of steam cleaner,is that
means dip the pieces into the boiled water ,& how long should take for this step?

what is the ideal handling wire for rhodium plating,stainless steel or copper wire
?i tryed to use the stainless steel but it was spoiled when i plated,& the
stainless steel grease was appeared in the rhodium bath.

how to electroclean the pieces,what kind of anode should be use ?what is the
temp,time & voltage.

Thanks,
Paul


#14

Dear Paul,

Hi. I will try to answer your questions and I know others will
too so between all of us, it’ll be more than you ever wanted to
know! :slight_smile:

 what is the meaning of steam cleaner,is that means dip the
pieces into the boiled water  

A Steam Cleaner is a piece of equipment. It boils water in a
specially constructed tank. The boiling water makes steam which
is released on demand by stepping on a foot pedal. The steam is
directed through a small orifice (nozzle) at about 60-85 lbs. of
pressure. This means you get a sharp blast of hot dry steam
that is extremely effective in cleaning jewelry.

what is the ideal handling wire for rhodium plating,stainless
steel or copper wire?  

Well, my vote is for copper. Technically you dont want to
introduce copper into the rhodium bath - but the first time you
use the copper wire it gets rhodium plated anyway. I’ve never
had a bath become contaminated from using a copper work wire.
My copper wire is pretty thin gauge so I take about 6 pieces of
wire and twist them tightly together to form about a 1/8" thick
piece of wire.

 how to electroclean the pieces,what kind of anode should be
use ?what is the temp,time & voltage.  

Here it depends on what brand of electrocleaner you buy.
Gesswein’s is used at about 160 degrees F., about 6-9 volts as I
recall, and 30 seconds is usually plenty of time for a thorough
cleaning. I use it in a stainless steel beaker so I attach my
lead wire to the beaker lip and the beaker itself serves as the
anode. If you were to use a Pyrex beaker, you could of course
use a stainless steel anode.

After electrocleaning, rinse thoroughly in tap water. Then
remember to give one final rinse in distilled water before you
rhodium plate.

I hope this has been of help to you.

Best Regards,

Elaine Corwin
GESSWEIN CO INC USA
Fax: 203-335-0300


#15
 at here i still have some questions,what is the meaning of
steam cleaner,is that means dip the pieces into the boiled
water ,& how long should take for this step?  

Paul, A steam cleaner is essentially a length of coiled copper
tubing with a nozzle at one end and a water source at the other
end and a heat source in the middle. Yoe heat the water up to
212 F. (100 C.) and steam blasts out of the nozzle - Voila -
steam cleaning!


#16
  Paul, A steam cleaner is essentially a length of coiled
copper tubing with  a nozzle at one end and a water source at
the other end and a heat source in the middle. Yoe heat the
water up to 212 F. (100 C.) and steam blasts out of the nozzle
- Voila - steam cleaning! 

This describes the oldest forms of steam cleaners, and the
newest, both of which are “steam on demand” with no storage of
pressurized steam. But the majority of steam cleaners are a
boiler tank, with an internal or external heater. Water is
either added when the boiler is cool, or pumped in with a high
pressure pump. The boiler is heated until it’s pressurized to a
suitable degree with steam, and a manual or electrically operated
valve controls release of high pressure steam through a nozzle.
The key to them all is that you need steam at a pressure of from
20 to 100 psi, or so. Most steam cleaners are designed to work
best in th 60-80 psi range for pressure of the steam jet at the
nozzle.

Peter Rowe


#17

Hi There, Would someone know that rhodium plated normally will be
lasting for how long ?

Paul


#18

I have seen a number of notices and warnings, notifying the
jeweler’s world that many of the Boiler-type steam cleaners
qualify as high-pressure devices and as such are prohibited,
licensed, or regulated depending upon your local
ordinances/state laws. Be sure you check before you
purchase/install one of these!!

Mike