Black Zinc Coatings

[XK120DHC]

I am wanting to "plate" all the nuts, bolts, washers, etc. off my '53 Jaguar XK120 DHC in Black Zinc. I have talked to the local platers about this process, they use a large tumbling drum, which I'm not real keen on as small items can fall out of the gaps in the drum.. Not a problem on a Ford, but a big problem on a fifty year old Jaguar as the parts are made from "Unobtainium"!
The plater and I talked about wiring the small pieces together, this should eliminate the loss factor.. but I'm still nervous.
Having done business with Caswell Inc. in the past, I checked my "Complete Plating Manual" (Ver 2) for Zinc Plating and Black Chromate. Then I checked the website and found that the Zinc Crystals aren't available.. My option is "Copy Cad" and a Blackening dip..
Given that I have about a hundred pounds of nuts, bolts, washers and some small parts that I want in Black Zinc, and I printed out the Excel File "Surface Area Chart for Hex Head Bolts", I was floored to find that four 5/16" x 1 3/4" bolts equal 11.37".. The Copy Cad Plating Kit can only plate 12 sq inches at a time.
Now the Question:
What size tank/bucket/pond would be needed to do a "serious" amount of pieces (I'm not wanting to make a career of plating these nuts and bolts!)?
How many Anodes?
At how much voltage/amperage?
I'm not wanting to "experiment" with these valuable Jaguar parts.
Cost is a factor.. The local plating shop does up to fifty pounds for $40.
Convenience is a factor, as I must sandblast ALL the nuts, bolts and small parts in a short time before delivering they to the plater.. I could do "batches" at my own pace.
Additionally, I would like to hear from those who have serious experience using the Copy Cad and Blackener in plating a significant quantity (excess of fifty pounds) of nuts and bolts to learn about the ease of plating, quality of the plating, and exactly how much a "kit" would cover.
Chas

[sccc]

Sorry, but I can't answer your specific queries, as I am in the same situation myself. But where does one find this "Surface Area Chart for Hex Head Bolts" spreadsheet? I could use that right now.

[XK120DHC]

Originally Posted by sccc

But where does one find this "Surface Area Chart for Hex Head Bolts" spreadsheet? I could use that right now.

I found it in "Rainer Muller's Chrome System" report on one of Caswell's webpages.. I had to do a "Search" (upper left corner) for "Excel Files" to find it again.. The link is: http://www.caswellplating.com/restgal/mueller.htm
Hopefully this will open the page for you..
Scroll down about halfway and look for the highlighted words:
"Surface Area.xls" and "Washer Area.xls".
The info will surprise you.. I was shocked to see how much surface area there is on a simple bolt.. the threads account for the "unusual" large size..
Hope this helps.
Charles.

[mcaswell]

Copy Cad IS a ZInc plating system. It will give you a professional finish on the parts you mentioned.
There is also a new zinc blackener available. See the webpage for details. If you get stuck, email us. The V2 manual is VERY out of date.

[sccc]

Charles, thanks! I got them downloaded. Strangely, I had tried to search on "Surface area" and came up empty. Never thought to try "Excel files".

After reading your original post, I measured a bolt for myself, and sure enough, they have a lot more surface area than one would guess just by looking. A 1/2" shoulder bolt 2" long is almost 2" in circumference as well! at 4 sq." each, I would be at it for weeks, so I decided a hefty power supply is in order.

BTW, the little wall-wart power brick supplied w/the kit is a joke. Using a 2x3" piece of mild steel to initially purge the copy cad mixture, I got nothing from the system. No fizzing of the mixture, and no plating. So I hooked up the voltmeter, and found that having 12 sq." submerged in the mixture would draw the voltage down to 0.45v. I gradually raised the test piece out of the mixture, and watched as the voltage increased. When it reached anout 0.9v, the fizzing began in ernest, and reached a moderate level at about 1v. By this time there was only 1 sq." of material left in the mixture. I held it there for 10 minutes, and it did plate nicely, but clearly this wall wart is inadequate to the task.