Ask the Expert Question-and-Answer Archive
(Hard Chrome Plating)
by Randy Taylor, Advanced Tooling Corporation.
August, 2006
Labor-Intensive Masking Alternatives
Q. I work as a methods analyst supporting a
hard chrome line. We use a very extensive and time consuming method of
Masking with lead tape all non plated surfaces followed by plastic tape, on
some areas where we cannot use plastic tape as our secondary tape we use
stop-off lacquer. Our gears and journal bearing surfaces and thickness
requirements have our parts in the tank for as long as 26 hours in some
instances. So chromic acid attack is extensive unless we use these heavy
masking methods. Are you aware of other tapes than lead/plastic that do a
good job at standing up to the chromic acid and a delivery means that would
in some cases take us from an order qty of 10 for up to 6 hours down below
three (50% gain or better?). Or are you aware of tape cutting by computer
program to enhance the speed? Any ideas are welcomed. Thank you in
advance.
A. Hard Chrome plating is historically "labor intensive". If it wasn't
for the superior wear, extended service life, and many of the other great
characteristics of hard chrome, or the fact that your customer won't take
"No" for an answer, one might conclude that often, "it's not worth the
effort!"
I come from a long line of "hard chrome platers" and there aren't many new,
exciting or innovative ways to "skin a cat" around a chrome tank these days.
On the brighter side, however, I happen to be part of a company which is
dedicated to making the plating & masking process easier and more operator
friendly. Our background is primarily with aerospace and aircraft "Hard
chrome process optimization", but ATC covers many other industrial hard
chrome categories. Most masking techniques we've all learned from the old
timers. These techniques vary widely from job to job, and generally do the
trick. But even the "old timer's" might be surprised to see how far some of
our latest processing techniques have actually come.
I'd like to help you, if I can. Let me start by saying that the real answers
you seek, may not necessarily come from better masking materials or taping
techniques, but rather, affective use of DC current, conforming anodes,
properly sized contact areas, state of the art rectifiers, well designed and
built plating racks and frames, and a variety of shields, robbers, thieves
as well as "no mask" tooling and fixturing techniques.
My true calling is hard chrome consulting, and when I'm not answering
questions on line at the STERC "Ask the expert" website, I run a company
called Advanced Tooling Corporation, in Middlefield, Ohio. We also have a
sales and information office in Scottville, VA. ATC has helped dozens of
companies around the country, improve their hard chroming skills, from
masking, through proper anoding, tooling, fixturing , bath analysis,
troubleshooting, environmental issues and a very special product line we
call "no mask anodes".
Let me know if I've helped to answer your question? Your certainly not alone
out there, there is much information and training available, however, that
will improve hard chrome productivity and quality. The bottom line in our
ever changing industry, is doing it better, faster, cleaner, "greener", and
more profitable.