Several months ago I was doing research into the traditional finishes as well. Much of my information was provided by damascus, but from others as well, including folks on this board, but from other boards devoted to violin and furniture refinishing as well. I was considering experimentation with copal varnishes, but ultimately decided that sourcing and processing of the original ingredients would simply not be either cost effective, or substantially superior to using more modern (and widely available) ingredients. Not to mention the hazards of making copal varnish at home.
Since most of the guns I'm working on are field and mid grade, I've settled on a combination Red (Andy's) Oil and French Polish method that I'll briefly describe here. One exception I'm making is a high grade Thomas Bland & Sons hammer gun, I'm not sure if I'm going to use traditional oil finish methodology on that one yet. French Polish appears to be fairly period-correct, at least for Parkers from around the turn of the century.
Once the stock prep is finished, I use a home-made Alkanet spirit stain. I've made two types, one with grain alcohol, another with a commercial stain base. It's very hard to tell the difference, if anything the commercial stain base appears to penetrate a little better. I then use the Andy's oil recipe from damascus. It is alkanet that has been soaked in 50/50 food grade walnut and linseed oils. Both are raw, and appear to be fairly pure. The raw linseed (flax) oil is considerably less expensive that the artist's grade variety. After staining at least twice over a two day period, and allowing another day to dry, I hand-rub in several applications of the oil, using only a few drops each time, over the course of one day. (once an hour, for a day). Then, after 24 hours, I drop to one application per day for one week. I allow a few days after the last application to insure the oil is dry, Since most of the time I've had to use a solvent soak on the stocks, this is usually long enough. I then French polish using a natural shellac, slightly amber in color. The Zinsser folks informed me that their amber shellac product is essentially the same formula as it was at the turn of the century. I use that straight from the can and cut it with alcohol to to the desired weight. It's a three pound cut in the can, so I cut to two lb. for the initial coats, then to one lb. for the final ones. I do use the guideline of 100 passes for the total application. I use Andy's oil for the lubricant during the French polishing. It really doesn't take that much time once you get used to the methodology. I usually rub with rottenstone to develop the final satin look. Once the finish is done, I paste wax at least three coats, usually four or five. It looks very nice, and I hope what I'm doing is fairly historically accurate.
After reading the previous posts in this thread, I'll experiment with exposing some Andy's Oil to air, and see what develops. I had considered adding some Japan Drier to it, but haven't gotten around to it.
I also use oxalic acid whenever I consider bleaching to be necessary.
Regards
Ken
Last edited by Ken61; 12/21/14 02:20 PM.
