finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
topic 4336

Chemical Polishing (Bright Dipping) of Aluminum


(2000)

Q. I have been looking at chemical polishing of aluminum with a phosphoric-nitric mix and was wondering what materials were used to make the baths, and what special requirements would be needed to pump the solution.

Nathan Havercroft
- Manhattan, Kansas


(2000)

A. The typical material of construction for bright dip equipment is 316L stainless steel. Be very careful of the L portion; it stands for extra Low carbon. If you don't use all 316L you will get chromium carbide precipitation in the heat affected areas adjacent to welds, which will corrode quickly.

Lee Branch
Richmond, Virginia


September 23, 2010

A. Hi, Nathan.

An additional aspect to consider is the need for a special ventilation system. This solution evolves clouds of mustard color toxic NOx, and lip-style tank exhaust is probably not adequate. The bright dip tank and the first rinse usually need to be installed in a "garage" ventilation system, and may require a two-stage fume scrubber rather than a conventional one.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


(2000)

A. If you go the route of electropolish instead of bright dipping (its not so extreme in its temperature requirements if that matters, and because of its use of electrical means its more controllable). The problem with the electropolishing being that the only true tank material they've found to hold the electrolyte and maintain a reasonable lifespan is Kynar(tm). Apparently its life is very good, but a sheet of the stuff will set you back 1200-1500 dollars, so you're looking in the neighborhood of 5K+ to put a decent sized tank together. If they could figure out a way around this, they'd have more acceptance I'm sure, but it's a large hurdle to jump for any shop.

Matthew Stiltner
plating company - Toledo, Ohio


(2001)

RFQ: I am looking for a vendor to perform aluminum bright dip operations. Our annual aluminum bright dip requirements are ~ 1500 pieces ranging from 28" x 1.3" diameter tube to 1" x 1" diameter machined part of alloy 1100 aluminum. If this is something within your capabilities and you are interested, I will need a description of the process and any quality systems you have in-place. I would prefer a vendor in the northeast.

Thank you,

James L [last name deleted for privacy by Editor]
- Horseheads, New York
outdated



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.