There are two types of boiled linseed oil. The first and original was linseed oil that was boiled until it became thicker and dried faster than raw oil. I'm not sure when but around WWI boiled linseed oil was getting hard to find and the new BLO was linseed oil with drier and other chemicals added. ALL the so called boiled linseed oil that I find is the chemically added stuff. I'm trying to, for lack of a better word, replicate some of the original finishes for restoration work. So far the stand oil seems to be about the same as the original boiled oil.
Each gunmaker had his own mixture and how he applied it. One method was to soak the stock with a mixture of raw linseed oil and turpentine (2-oil 1-turpentine)many put this coat on warm or hot. European thin shell walnut would take about three or so coats, American black walnut could go as high as twenty+. Once the wood would not take anymore oil and once it was dry they then used boiled linseed oil for the top coat(s).
