16 December 1941
From: The Chief of the Bureau of Navigation.
To: All Ships and Stations.
Subject: Identification Tags.
Ref.: (a) BuNav. Circular Letter #57-41 of May 13, 1941.
1. On ships and stations inaccessible to ships and stations which have been furnished with graphotype machines, it is directed that the data which is placed on the face of the tags by the graphotype machine be etched on with nitric acid by members of the Hospital Corps.
2. In inscribing the data required to be placed on the face of the tag, use a blunt pen and diluted printer's ink. The ink can be thinned with gasoline or turpentine. Turpentine is preferable as it does not dry so quickly. Have this data written out on paper in advance so that it can be quickly inscribed on the tag without having to delay by questioning the person for whom the tag is being prepared. The ink should be just thin enough to write with. If it spreads on the metal, it is too thin: if too thick, it will not flow from the point of the pen. Be careful not to smudge the fingerprint while placing the data on the face of the table.
3. The next step is the application of the gilsonite or asphaltum. This should be fine enough to pass through a sieve having 100 meshes to the square inch. Sprinkle thickly on the two wet surfaces. Remove what does not mix with and stick to the ink by tapping and blowing.
4. The tag is now held with forceps over a flame or stove until the ink and asphaltum have melted together, forming sharp, glossy black lines.
5. If not enough heat is applied to completely melt the asphalt the action of the acid will be too powerful. Complete melting of the asphalt is indicated by the lines becoming glossy. If too much heat is applied the lines run together and are obliterated. The etching solution consists of concentrated nitric acid, one part by volume; water, two parts by volume, plus a small quantity of hydrochloric acid.
6. The solution may be placed in glass, china or enameled ironware (if there are no nicks or cracks). A number of tags can be etched at once, but do not pile them one on top of the other. The name side should be up, and the fingerprint side down while in the acid bath. This will favor deeper etching on the name side, which is desirable, as it will not wear off so rapidly.
7. The etching process or acid bath should be watched and a tag lifted out from time to time to see how lively the action is. It can be moderated by adding water. Usually the process of etching requires one hour. The acid solution naturally weakens with use and should be renewed from time to time. If the corrosive action is slow in the beginning, concentrated muriatic acid (HG) may be added--one part to every thirty of the nitric solution.
8. Tags and necessary equipment for etching the tags may be obtained at either the Navy Yard, New York, or Navy Yard, Mare Island, California.
9. The Bureau also directs that monel identification tags be prepared and furnished the officers and enlisted men of the Coast Guard.
10. At one end of the tag, the letters USCG should be stamped or etched on the face of the tag issued to officers and men of the Coast Guard.
Particular attention is invited to paragraph one of Reference (a) which directs that Identification tags be issued to each officer and enlisted man of the Navy and Naval Reserve. Commanding Officers will take immediate steps to see that officers and men are furnished these tags. -
J. F. Shafroth, Assistant Chief of Bureau