Hi all and apologies if this has been asked before but I have not seen this asked recently.
I have to gold plate (acid based not cyanide) on silver and have wondered whether 1 longer plate would be better than several shorter based layers. I am aware that whatever I do is not likely to be durable but the items are going to sporting medals which won’t get a lot of wear and tear after presentation.
Thanks for your advice,
Roger
All gold plating on silver requires an “underplate”. Usually nickel but I believe that palladium works but is more expensive. The problem is not the wear but the silver oxidation will show through the gold plating.
Thanks Phil, appreciate the response. I was wondering about the fire scale etc - looks like another plating solution goes on the shopping list
Do you reckon platinum plating would work just as well as the palladium - its about half the price
From what I remember, the issue wasn’t oxidation of the silver so much as the fact that the gold dissolves and diffuses into the silver layer whilst it is being plated. The result is a tepid greenish silver. The gold won’t however dissolve into nickel or platinum.
You can demonstrate that by burnishing gold leaf onto fine silver with a standard gilders’ agate burnisher; the result is a greenish silver. Gold foil (which is very considerably thicker than leaf) works tolerably well (this is very close to the keum boo technique).
45 years in the trade and I’m still learning. Thanks for your help
I, unfortunately, have a lot of experience with acid gold plating over large sterling cast pieces and it’s a one way road - to heartache and misery.
My experience has, with few exceptions, been an eventual discolouration - purplish, brown spotting that occurs in 3 months, 3 years or 3 decades. This result has happened with no nickel, acid copper with nickle, cold nickel, hot nickel, copper flash, 50 mils gold, 100 mils gold. You name it, I feel as though I’ve tried it. Some how, some way the gold and the silver chemically want to find each other and bond and the spawn of that bond is purple, brown splotches.
As my product is cast, I’ve always wondered if the problem was accelerated by the lack of density, on an absolute, relative scale, as compared to a struck or milled sterling items. Could an otherwise mirror finished cast piece [predominately large belt buckles] still possess “micro” pores that, in time. leach out the multiple chemicals in the baths along the plating line prior to the final tank of acid gold?
Another line of inquiry could be made as to atmosphere has an effect, the way it would on the time-to-tarnish on traditional sterling. Humidity, salinity, fingerprint oils, I’ve suspected as playing some part, perhaps.
The wisdom I’ve accumulated over the years would barely fill a thimble. In essence, Gold over Sterling -beware. How hundreds of years old gilded silverware has held up, I’ll never know.
Best practices, as indicated in prior posts, include a copper strike, pre-plate of nickel [no direct experience with Pt or Pd] followed by a high mill layer of acid gold. Even so, my 3 year warranty on plating defects gave me a fairly regular source of re-plate projects.
Good luck. [Am I bitter and PTSD about gold plating? You bet.]
Thanks for your reply Jeff and can understand that your heart sinks when the items come back for attention.
My items will be hand made so very little in the way of castings and once presented may not be handled for long periods. I hold out hope that a lot of the problems you have experienced might be due to cast components.
I’ll take on board what you have to say and may have to expect that there will be returns over the years.
Take care,
Try a cyanide based plating solution. I have always used cyanide based plating solutions. I used to be an ecclesiastical silversmith. I made chalises , patens, and pix. The chalices were all 24 kt gold plated inside the cup, the paten surface that touched the host , and the interior of the pix boxes. I have a couple of pieces that I made that are over 50 years old that are still bright gold.
I’ve never used acid plating solutions. So it may be the issue of the chemical composition of the plating solutions.
Cyanide will only kill you if you contaminate it with acid, handle it without gloves on your hands, or drink it. I used to work in a mass manufacturing class ring and pin manufacturing plant. We had and entire conga line of multi gallon tanks of cyanide plating solutions that were uncovered during plating. I’m still alive and so are the now retired owners.
Jo
Thanks Jo,
I have to wonder whether the limited times that I would be using the plating would be worth the cost of setting up and the regulations involved in using cyanide solutions. At this stage we are looking at perhaps fewer than a dozen item a year and having it outsourced and being done elsewhere is cost prohibitive.
Thanks for your input and perhaps if the need increases we may well look at the cyanide solutions.
Roger