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

on this site
current topics
topic 2844

Student Question: Uses or sources of boric acid, fluorine, and barium sulfide

Boric Acid Powder
(2 lbs.)


If anybody can give me some info., I'm doing a research assignment on plating and coating. I am the mock CEO of a mock plating and coatings company, and my instructor has given me a list of chemicals to do a waste minimization report on. I have been unable to find the uses of some of the chemicals in the industry. The chemicals are boric acid, fluorine, and barium sulfide. Any info on the uses of these chemicals would be appreciated. thanks,

jake hairell
- spring, texas

Boric acid is kept in the bathroom medicine cabinets of plating shops as an eyewash. Putting smaller eyedroppers in the bottles might help reduce waste, not just in plating shops, but in the school nurse's office as well :-)

Boric acid is also used as a buffer in acid plating baths. Elemental fluorine is not used, but hydrofluoric acid and fluoboric acids and acid salts are widely used. Sorry, I'm not familiar with barium sulfide.

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


Boric acid is a wonderful buffer for plating baths. H+ ion is frequently removed from the diffusion zone which is possibly a millionth of an inch thick on the part that you are plating. This raises the pH and forms a ugly or bad or both plate in acid plating solutions (baths). Boric acid has 3 hydrogen ions that will come out as required to maintain a pH on the surface. They come out at 3 different pH's, so are wonderfully useful in lots of different plating solutions. It has a tendency to make the plate white or bright, this is because it maintains the pH very well. Higher pH's tend to give a dark or even black look that is sometimes rough. A buffer is a chemical that will resist the change of a pH in either direction.

Fluorine is a gas that is extremely active and very dangerous. "Fluorides" are in plating in etch/activation tanks and a few plating bath. Fluoboric acid is much more common in plating baths. Ammonium bi fluoride is the safest way to get the fluoride ion as hydrofluoric acid is very dangerous, possibly the nastiest acid to work with in a concentrated state. It eats glass!

I can not imagine a use for barium sulfide as barium forms rather insoluble compounds as does sulfides. Barium sulfide should be extremely insoluble. Both are hazardous materials and require special handling, more so than than some other plating materials.

James Watts
- Navarre, Florida


Barium sulfide can be used for putting blue and brown coatings, or patinas, on metals like brass, bronze, and copper.

dave wichern
Dave Wichern
Consultant - The Bronx, New York

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


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

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.