As an Amazon Associate & eBay Partner: we earn from qualifying purchases
Mr. Rogers: "Look for the Helpers. You'll always find people who are helping."

Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Adver-
tise
Help
Wanted
Current
Q&A's
Site 🔍
Search
finishing.com -- The Home Page of the Finishing Industry


  -----

Why Anodizing Uses a Hollow Copper Work Bar

Quickstart:
     In production anodizing and plating, it is usual to suspend one or more plating racks from a copper bar or aluminum & copper structure that spans from one side of the tank to the other. This bar is often called a work bar or flight bar.
     The tank is equipped with copper or brass contacts (often called saddles or v-blocks) mounted on the rims of the tank and bussed to the power supply. The bar sits down on these saddles. The bar carries the anodizing or plating current from the saddles to the racks; the racks in turn are conductive, carrying the current to the workpieces.
    

61853

Q. Curious as to whether it matters if a copper flight bar for anodizing work is hollow?

That is to say, if the copper flight bar is like a pipe, but with closed ends, versus a solid piece of copper all the way through, will this potentially affect anything like carrying capacity?

I've usually seen solid pieces of copper or aluminum for flight bars.

Matthew
Employee - Illinois
July 1, 2025

Tip: This forum was created to help build camaraderie among enthusiasts around the world through sharing tips, opinions, pics & personalities.
The operator & those readers who still want that might not engage with anonymous posters.


"Electroplating Engineering Handbook"
by Larry Durney
EEHcover
on eBay
or Amazon
or AbeBooks

(affil link)

A. Hi Matthew

The DC current used in anodizing and plating runs through the conductor, not on its skin as in some AC applications. So the reason for using a hollow bar is because more strength can be gained from a hollow tube than from a solid bar of the same weight.

For plating and anodizing purposes, a rule of thumb is that the current carrying capacity of copper is 1000 Amps/sq.in, and 500 Amps/sq.in. for aluminum.

But the work bar must also be strong enough for the span and the weight of the racks. Often this means that a hollow tube meets the load carrying and current carrying needs better than a solid bar; it's not unusual.

Luck & Regards,

ted_yosem
Ted Mooney, P.E. RET

Striving to live Aloha
(Ted is available for instant or longterm help)
finishing.com - Pine Beach, New Jersey




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread


Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Finishing
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g,
& Software


About/Contact  -  Privacy Policy  -  ©1995-2025 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"