Thanks for the nice comments. I do appreciate it. For me, horn work is always more of a struggle than leather work. I have to use the old adage about thinking it through three or four times before cutting anything.
To answer the questions:
I was looking at John's article in the last Horn Book, published before Dixon's. I haven't seen a "new" issue yet.
In essence, John's dying method replicates what might have been done in the 18th. century to color a horn. He notes that there certainly seem to be old horns that were colored, not just left to the elements. Aqua Fortis and Manganese Permanganate were available in that time period and used regularly for other things.
To dye with AF, clean the horn thoroughly with denatured alcohol to remove any trace of oils. Always wear gloves for the entire process. AF is an acid, and it is nasty stuff. Wipe a coat of AF on the horn, trying to cover it as evenly as possible. It will streak if it is not even. I put the tip of the horn on a steel rod clamped in a vise so I can rotate the horn on the rod while coating it when I start the whole project.
Let it dry for 20 minutes maybe. Wipe on one more coat to be sure it is covered. Let dry again. With a heat gun on pretty hot (I use 750 degrees on mine), start working over the surface of the horn. You have the get the horn really hot to activate the color in the AF, but you you do not want to burn it. You will see it change color and turn yellow. Keep working over the horn until you are satisfied.
If the yellow is not full enough, let the horn cool back to room temperature and repeat the process once more. Two coats are usually sufficient to get a good, deep yellow color. Every horn is different, so there is no "rule" about this. Be sure and let the horn cool. AF gives off a pretty bad set of fumes if it applied to a hot horn. A fan nearby might not be a bad idea, or work outside.
If the horn is too yellow, too bright, or whatever, you can cut it back and add more brown/gold tone to the color with the Manganese Permanganate. Again, wear gloves. This stuff does not seem as toxic as the AF, but it will stain you.
Put some MP on a cloth (while wearing gloves) and start wiping it on the horn. Different horns will react differently to this, and it is almost impossible to really control the reaction in my experience. You will want to keep a clean cloth around to wipe excess off too. Keep wiping it on with fresh applications to the cloth until you get the color you want. This can range from a nice darker yellow to orange-tinted, to a real brown. Practicing this whole process on a junk horn might not be a bad idea too.
Hope this answers the questions about the process.
Jeff
