Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





"Boric acid level in a sulfamate nickel bath"



-----

 

I hang anode bags full of boric acid in my sulfamate nickel plating baths, and I find myself refilling them all the time. Can I dissolve too much boric acid in the bath?

Michael Brewington
plating shop. - Salisbury, Maryland, USA



 

You can not add too much. A saturated solution is optimum.

The boric in the bag is subject to a significant agitation and saturates the bath at working temp. When you shut down, agitation and temperature both drop and the saturated solution becomes supersaturated and precipitates to the bottom of the tank. On Monday, the process starts over.

You very probably have a thick to very thick layer of boric on the bottom of the tank.

James Watts
- Navarre, Florida



 

Well, you can't dissolve more boric acid than the solubility limit. But the problem is that if your 140 degree tank drops to a lower temperature, boric acid will precipitate and you will have particles that don't readily dissolve, and that will cause you problems.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey



 

Michael, boric acid should be maintained at an optimum level, in decorative nickel, 6 to 8 oz/gal. Prevents burning and pitting just to name a couple. Using an anode bag to maintain boric in the bath has been around forever. Yes it is consumed during plating. Don't you or a vendor run routine analysis on a regular basis?

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan



 

Hanging a bag of boric acid in the tank is common. You want the bath to be at or near saturation. The only time you could get excessive boric in the bath would be if the temperature was excessive.

James Totter
James Totter, CEF
- Tallahassee, Florida



 

Michael,

I think that you should analyze for boric acid and make additions based upon the analysis. My experience is that boric should be maintained between 4 and 5 oz per gallon and NOT above that. The reason is that the boric is soluble at 140 deg F but the work piece entering the solution is only around 75 deg F. If the boric is going to crystallize out of solution, it is most likely to do so on the cold work piece and cause rough plating.

Pat Mentone
Pat Mentone
St Paul, Minnesota


none
finishing.com is made possible by ...
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    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA