Copy Chrome questions

[68commando]

I have been using the PNP copy chrome kit for a while now. If you look at the picture, there is a rough plated area above and to the left of the hole in this item. Why is this happening? Could it be lack of cleaning

Also, I have been plating things for about 5 minutes per the instructions using the dip plating instead of the brush plating and now I have upped the time to 1/2 hour to be like the big kits. I noticed that some of the parts I only plated for 5 minutes were rusting and have uneven plating on them. Should I be plating for 5 minutes or 1/2 hour?

Thanks,
Dave

[mcaswell]

It really depends whether you were immersion plating, or not.

If you were brush plating, the rate of plating will depend on the speed you move the wand around, and the total area you try to do in one job.
The actual power supplied to the wand from the adapter is approx 1/3rd amp, and as the required immersion time is 1 amp per 16 sq ", you should plate, in theory, 5 sq" with the power going to the wand. However, the surface area of the wand, if it is kept still, is about 1/2 sq", so there is much more power going to that small area. This makes the wand plate much thicker and faster. How much is difficult to determine, because the wand is not stationary.
You will see this if you keep the wand still, you'll see it will burn the area because of the excess current.
Brush plating is a rather primitive method of plating, but if used correctly is ideal for these smaller areas. The downside is it needs a little practice to find out what will work for you.

When immersion plating using PNP, you need to consider that the power supply is putting out a constant 300ma - 1/3 amp and will plate about 5 sq" with most solutions. If your part is only 1 sq" you need to place something else in with it to make up the surface area to 5 sq". It will then plate at 1 thousandth of an inch per hour.

[68commando]

Mike,
Thanks, I have been using the immersion method with the PNP, however, I have a variable voltage power supply that I am using with it. I have hooked up a small ma meter to keep track of the current, and I am keeping the current at about 50-60 ma per sq inch which translates to 1 amp per 16 sq in. Most of my parts are quite small as in the picture so I am usually only plating about 1 sq inch, so I keep the current at the 40-60 ma range. I guess if I want a thicker plate, I should plate for about 1/2 hour. Some of the stuff I plated for 5 minutes seemed fine when they came out and after polishing, but seemd to haze over in areas after a few days. I'll see how the longer plating stuff turns out.

Dave