No passwords, No popups, No cost, No AI:
we earn from 'affiliate link' purchases, making the site possible

Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

finishing.com -- The Home Page of the Finishing Industry

  The authoritative public forum
  for Metal Finishing since 1989

-----

Raising a destroyed (ground down) Hull I. D. # on an Aluminum boat

Q. I'm a firearms examiner at the [surname deleted for privacy by Editor] Police Dept. Crime Lab. I'm working on a research project involving serial number restoration on titanium and scandium alloy firearms. In a nutshell, serial number restoration uses chemical etchants (acids) to enhance obliterated characters from metals where plastic deformation has occurred in the crystalline structure of the metal.

What acids can SAFELY be used (i.e., Not HF) on Titanium? Any thoughts on what to use on Scandium?

Thanks in advance...

Jill E [surname deleted for privacy by Editor]
Crime Lab - Florida

Q. I am a Marine Deputy Sheriff and we are trying to raise the HIN on an aluminum boat that has been purposely ground down so as to try to disguise the proper ownership of this vessel. I recently attended a training session that showed how to use a chemical soup [ ... ] but the instructor wasn't quite clear on this.

Nicholas J [surname deleted for privacy by Editor]
- Coos Bay, Oregon

March 30, 2009

Hi, Jill; hi, Nicholas. There are many books and blogs describing such methods:

- "Crime Scene Training" at www.csitechblog.com/2011/07/how-crime-labs-restore-obliterated-serial-numbers.html
- "Idaho State Police Firearm/Toolmark Procedure Manual, Section 7: Serial Number Restoration" at www.isp.idaho.gov/forensics/documents/currentAMs/Firearms/Section%207%20serial%20number%20restoration%20rev%200.pdf
- "Serial Number" at what-when-how.com/forensic-sciences/serial-number/
- "Handbook of Methods for the Restoration of Obliterated Serial Numbers" by Richard S. Treptow at books.google.com.br/books/about/Handbook_of_Methods_for_the_Restoration.html?hl=pt-BR&id=0_HdHAAACAAJ

... but we deleted your partial explanations so that we don't make it easy for people who have ground off serial numbers to check the reliability of their work if you described an unpublished method :-)

If any reader can fill you in on these details that weren't clear, we will be happy to direct their response to you or put them in contact with you.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
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: