The Basics Of Electroplating To Get Rid Of Brassing

[Addertooth]

I posted this in the Waterman forum as a response to someone who was concerned about brassing on his celluloid bodied pen clip. I thought it might be of use to the entire forum. So I post it here.

 

 

Home plating is not difficult. The hardest part is the surface preparation of the metal before the plating.
Before you get started, mask any areas which you are NOT plating. It protects those other parts from physical abrasion and chemical attack.

Step 1, get it smooth, often that rolled gold finish has a sharp edge and the underlying brass is intentionally rough, to enhance adhesion of the rolled gold to the brash. Polish it all until it is equally smooth, and no apparent transitions from where the rolled gold remains, and where it has worn/torn away.

Step 1b, if any original engraving was obliterated during the polishing phase, restore it. There are two general families of engraving. The first is machine or displacement engraving (stamping, rolled imprint, diamond stylus) which pushes the metal out of the way (like a bulldozer) but does not remove it. The second is classical chisel style engraving, which actually carves metal away. The latter type is seen in some of the precious metal bodied pens which have artful hand engraving on them.

Step 2, clean, I mean super meticulously clean, with the masked off parts safely covered, get them visually clean, then don latex gloves, get out alcohol wipes, then wipe the surface down (you are about to plate) to remove any oils your skin put on the metal. Residual oils can interfere with the plating process. Rinse the surface with distilled water to remove any trace of what was left behind by the alcohol wipes.

Step 3, Plate, basic gold kits are less than $100, and you can buy the replacement "plating solution" for about half that price. In your application, you will likely want "brush plating solution" as versus "dip solutions" which require immersion. My photos below are using the dip method.

Step 3b, rinse, rinse rinse, rinse all of that plating chemical off your pen. It may affect color or other characteristics if left in place.

Step 4, With a jewelry cleaning cloth, buff aggressively, the initial finish after plating will look rough and discolored. Only with buffing will your initial horror abate. The underlying brass contaminates the solutions and places a layer of rough dark copper on the surface (you will believe something went horribly wrong with your plating). Did I mention buff with a jeweler's cloth, yes, I meant it.

Step 5, Admire.

Below is an example of a practice piece which was only lightly cleaned, there was no pre-plate polishing (no Step 1 was performed, for test reasons, I wanted to evaluate adhesion with poor surface preparation). Then the part was plated for about 30 minutes (at 140 degrees F) and the plating solution was carefully rinsed away, so it would not chemically attack the other parts over time. It was buffed with a jewelers cloth.

Pictures: Before Plating, During Plating, After Plating. Once again, this was initially a parts pen purchased for $53 to do cruel experiments on, pity it not.

Note the extensive Brassing in the Before picture (the first picture).

Due to the lack of surface polishing before the plating, you can see a change in smoothness in the plated areas, as that area was rough brass instead of the glossy rolled gold. This is to be expected if you skip the surface polish stage prior to plating.

Edited August 12, 2019 by Addertooth

[eckiethump]

I have been doing quite! a bit of tank, gold electroplating recently,now I bright nickel plate, prior to gold plate, gold is permeable and eventually base metal wil tarnish through. As op points out,preparation and cleanliness are paramount.

[Addertooth]

Eckiethump,

Extremely valid point. I wanted to start out explaining the basic process, and avoid scaring people off. But you are correct, throwing down a base nickel plate, prior to the gold plating is the best "long term" course of action. The thickness of your plating also affects how long it will take before tarnishing begins to show up. A polishing cloth will remove the tarnish as it starts to appear as well, restoring your finish (i.e., if the tarnish shows up, it will wipe off). The tarnish was useful to me the other day, as it allowed me to determine (due to the tarnish color), that a pen was Vermeil (gold plate over sterling silver), which was rare on a specific model of pen. For that pen, the majority of them were gold plate over brass. But some of the models maded during WW 2, were made out of a sterling base metal, due to the wartime brass shortage.

Edited August 12, 2019 by Addertooth

[Paul-in-SF]

I have a question about brushing on the plating solution vs. dipping - in your example you dip-plated for 30 minutes at 140 degrees. How would I translate that into time and temperature for brushing? Do I keep brushing on heated solution for (say) 30 minutes? How does that compare in terms of effectiveness for the end product?

 

Oh, yes, what do you recommend for masking the rest of the pen? Is there any type of masking to avoid?

 

Thanks for this information, by the way, it's very intriguing, I have several pens with severe plating wear on the clip, cap ring and lever.

Edited August 15, 2019 by Paul-in-SF

[Addertooth]

I will use gold as an example. Brush plating solutions/gels for Gold are a much higher concentration of gold, than dip solutions, this allows for more rapid plating, and for cooler temperatures. Because of the higher concentration of gold, they tend to cost more per ounce. A two ounce jar of brush plating solution costs about a hundred bucks, dip solution is less than half that cost. You also need a brush-friendly wand. The Wand is covered by a cotton swab which is saturated with the brush plating solution/gel. I normally would not warm a brush plating solution/gel, or if I did, certainly not as hot as 140. Plating too fast results in a rougher finish.

 

As far as masking, the first element is it must be fluid tight. I would not want to risk the body of the pen being discolored by the plating solution. You can go as radical as using a wax with a low melting point for celluloids, but on hard rubber (which is porous) you should likely avoid waxes. I might use something as simple as multiple layers of cling wrap (which must be tested to make sure the plating solution does not affect the wrap), and then some other element to help seal the edges. For the sanding and polishing stages (prior to plating) I tend to prefer blue painters tape to prevent scratching the body as the clip/lever is being polished. And as always, ruthlessly rinse after plating to avoid any lingering salts from the solution from affecting the pen long-term.. As you saw from the picture, the black hard rubber of the ring pen was unaffected by the plating solution, so it was not protected. I intentionally put a drop of the plating solution on the inside of the barrel where it would not be seen, and left it there for an hour, to see if any change in color or texture of the hard rubber occurred. It did not, so in this case, I did not wrap or protect the hard rubber from the solution. This was a risk, but as the pen was a Test Mule for the solution, it was part of the overall exercise.

 

Brush plating is really not time based. My standard is simple. However long it took to get a good/uniform gold color on the plated part, triple it. i.e. if after 4 minutes you have a beautiful uniform gold plating on the clip/lever/ring, then continue for 8 more minutes. The key thing to avoid is uneven application, it is a pen, not palomino. Brush plating tends to be much faster, due to the higher concentration of gold.

For truly lasting results, an underlying layer of nickel is preferred (as pointed out by Eckiethump, as it requires less polishing in the future).

[eckiethump]

The information you are imparting here is excellent, I might even try, having been advised not to, by well respected persons, brush plating. With patience and possibly multiple applications ? It could replicate results of dip plating ?

[Addertooth]

Where 99.9 percent of people go wrong with plating falls in 3 areas.

1. improper masking, they end up scratching stuff in the polishing phase which is not the plated part.

2. Improper polishing of the part you are about to plate. Gold plate will never be smoother than the underlying metal. If you cannot polish brass until it is shiny, then plating is not for you.

3. They Plate too thin, or plate too fast. Too thin makes a finish that rapidly fails in its appeal, plating too fast results in a rougher finish. The instructions which come with most plating kits are "okay" but hardly an exhaustive treatise on the process. Remember, if done right you are making a change which will be enjoyed for years... a bit of time and effort is worth the result.

 

Other more experienced hands have reasonable concerns for the level of skill you may employ, as they may not know the level of effort you put into projects. Slow and easy, focusing on perfection, instead of "close enough" wins the day. There are some that view plating in the same vein as blackening faded hard rubber. They see it as a "cheat".