No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

citric acid Passivation with Spec. QQ-P35?



 

ASTM A967 [affil link] allows for citric acid passivation, but what about QQ-P-35C [affil link or DLA] ? I don't see any mention of Citric. Could we use it and be in compliance?

Enrique Segovia
- Monterrey, Mexico


Sorry, No! Although the spec. has been discontinued, it is still being used by many, and unless the spec. can be substituted with the ASTM standard you MUST use the specific chemicals and concentrations noted in the mil-spec. ASTM standard is much more lax in the methods to achieve passivation- concerning itself with the end results as opposed to the means.

Bill Grayson
- Santa Cruz, California, USA
 


Hello Enrique!

Unfortunately QQ-P-35 mandates that you use one of the solutions that are listed, so you can't use citric acid solutions and certify to QQ-P-35, UNLESS you take exception to that portion of the specification. We have a number of vendors who take exception to various portions of our drawings or specifications before they process our parts, and these requests often find their way to my desk for engineering analysis. Sometimes we allow the exceptions, sometimes not, but you should ask.

Good luck!

lee gearhart
Lee Gearhart
metallurgist - E. Aurora, New York
 


 

Enrique:

Nobody should be citing QQ-P-35C [affil link or DLA] as a specification for passivation, since it has been long since cancelled. However, many companies take a long time to change prints, etc. The U.S. DOD has cancelled it in favor of ASTM A967 [affil link] , which allows the use of citric acid formulations on all applications except aerospace.

If you are doing aerospace parts you need to use AMS2700 [affil link] or AMSQQP35 [canceled, affil. link]. AMS2700 [affil link] allows the use of citric, AMSQQP35 [canceled, affil. link] does not, at this time.

So, unless you are doing aerospace parts specified to AMSQQP35 [canceled, affil. link], you can use citric formulations. See our Web Page for more details on this. Call us if you do not understand.

lee kremer
lee kremer sig
Lee Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois
stellar solutions banner


none
www.finishing.com is made possible by supporting advertisers ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages



(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:

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


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"