Girl needs help with Black Krome

[justtobeme2]

I am using PNP (first time user) and I was instructed to put a base coat of copper. I buffed my item (corset busk) I plated it with copper everything went fine (have already done gold and it went fine) and then I went to the black krome I got in the mail today. It plates splotchy at best and 50% of the time not at all. I cleaned and cleaned and buffed and cleaned some more. I heated the solution,I heated the item, I used the wand (SS wand)I used the dip method with the wand one one side and the alligator clip hooked to the other, I tried another busk that seems to be nickle or zinc just to see if it was the copper and I got the same result. Please help!!Just on one little busk which has 5 things the size of a nickle (which is all I am plating) I have used 1/3 of the bottle and still negative results.

[andoverite]

Hello,

I received my PNP Black Krome kit earlier this week; today it's Thursday of the same week and I have yet to get any semblance of a plating. I used fresh 5 mil thick brass (70% copper, 30% Zinc) shim stock (6"x1") as a trial specimen. One third of it's surface area was left untouched with the milled finish, while the remaining two-thirds was fine polished with 600 grit SiC Buehler "metallographic sanding paper". The 600 grit polished surface was further divided into one-half that was treated with oxalic acid metal brightner solution, while the other half was not subjected to the metal brightner. The metal brightner left an obvious demarcation line between the treated and untreated halves. All processings were followed by thorough water rinses. Finally, the whole strip was given the directions-suggested light "Soft Scrub" polishing followed by a full water rinse and paper towel drying. One small central area was covered with masking tape in order to pick up and handle the brass strip. The plating directions were followed as best as the skimpy directions would allow. Electrical continuity was checked between the ss metal wand and the brass strip attached to the alligator clip of the power supply. Not only was there electrical continuity but there was 7.5 volts between these two points when the power supply was energized with 110vAC. Sofar so good. The wand was wrapped with the provided bandage in a manner that gave a covered wand as depicted in the instruction booklet. The plating solution was well shaken before pouring off a small working amount in a separate plastic container, as suggested in the directions. The wand was dipped in the original plating solution container as recommended, until the bandage was thoroughly wetted with the plating solution. The alligator clip made contact at about the middle of the length of the brass strip, so the wand was never farther away from this contact by 3".

Plating results after 30 minutes of stroking the sample? None, nada, zip, zero. I could see the "sizzle" or foaming caused by gasses generated from the chemical reaction, but no plating; just a slight darkening of the surface. There was no noticeable difference for the three differently treated surfaces. All surfaces did not become covered with a black coating. At best, there was a dulling of the bright brass finish. There were small areas that looked like they had a splotchy metallic blue coating, perhaps due to oxidation from the released oxygen gas "sizzle"(electrolysis of water?). At any rate, I'm very disappointed at the results.

I took one step backward, to a more basic experiment using refrigeration grade Copper 3/8" tubing. The point being that perhaps the Black Krome would plate better on pure copper compared to brass. The copper tubing was prepped again by fine polishing the total length (about 5") using 600 grit SiC metallograpic sanding paper, followed by water rinse, then polishing with "Soft Scrub", a thorough water rinse, and paper towel drying. Went through the same plating procedures as described above and as per the accompanying directions. Results? Same as above with the brass sample. Nothing but a dulling of the bright copper finish.

So, I'm in the same quandry that the previous writer is in. We need more specific information regarding what one is to expect and at what timeframe. What is the plating rate for this plating kit? Should I expect a full dark coating by 30 minutes of stroking? What are the signs of plating going awry or going correctly? Is there any quality control on the solution? Is there an optimum plating solution use temperature range? Is there anything I can observe that should alert me that there's something amiss after a given elapsed time?

There is one point that needs attention from the manufacturer of the power supply. There apparently is no "bleed-off" resistor to discharge the capacitor in the power supply. Several days after I used the kit on the brass sample, I started to hook up the kit for the experiment on the copper sample. I was very surprised to find that the power supply still measured 3.5 vDC, even though it wasn't even plugged into a 110 vAC power source. In other words, after three days, the power supply had discharged so slowly that there was still enough charge in some capacitor in the power supply as to maintain 3.5 volts. To check this, I plugged the unit into a 110 vAC source and measured the output; it was 7.5 volt, as it should be. but when I pulled the plug from the 110 vAC source and measured the output voltage it was still 7.5 volts. I had to wait several minutes before the voltage started to drift downward. Placing a 30 Kohm resistor across the ouput, brought the voltage down to zero volts, where, for safety sake, it should be immediately after pulling the power plug. Since I have no idea how big the capacitor is in this power supply, I can't determine how much energy is stored there, or how big a jolt it will impart to someone who accidentally grabs the two contact terminals of the power supply after removing it from the 110vAC power source.

[cbrooks]

To process any of the copper alloys you may need to pickle first in order for them to readily accept plating and to get complete coverage. You can use the pickel #1 (20 parts of water and 1 part of muriatic acid) or pickle #2 (2 parts water 1 part muriatic acid) or pickle #4, where you would immerse the part for 1-5 minutes, rinse with distilled water then apply your plating. This will acitivate and mildly etch the part which will allow for acceptance of the plating.