This is what I use mineral paint thinner, oil varnish and linseed Im sure its not traditional - you can use this for many processes with good results , touch ups . I have tinted - colored this mixture with LMF stain with good result . My subjective opinion if you have not applied much finish try your formula on other than the rifle .
Shop made Linseed Oil varnish is traditional and was common before the making of Linseed oil finishes was industrialized varnishes were made in house by the gunsmith. That very dark finish seen on some original guns and rifles is not shellac. Its a linseed oil varnish. They added drier metals, lead acetate/carbonate etc was one, and cheap resins such as rosin, gum benzoin and others to make the varnish more water resistant.
IIRC JP Becks estate contained a “paint pot” which I am sure was used to make small batches of varnish for gunstocks.
Back to the black coloring. This varnish, commonly referred to as “brown varnish” I am told, will darken or even turn black due to the emissions of coal fires. Thus they are often much, much darker than when applied. Shellac does not do this. Finally furniture finishes, violin varnish etc are NOT very durable as a gunstock finish. The Violin Varnish for example was part of the tonal quality of the wood. And they used much harder resins such as Copal. But these high temperature resins were much harder to combine with the oil and unless very carefully done the heat would ruin the varnish. AND these were more brittle and likely to crack or craze with rapid temperature/humidity changes. A finish that does this on a firearm is useless for protecting the wood. A properly made “soft’ linseed oil varnish is actually elastic and will move with the wood without failing. If looking at 19th c rifles with this finish it will be seen that a dent cause by a rounded object will not break the finish unless very deep or done with and object that has a sharp edge that will break the surface film. A very hard, non-elastic plastic finish used on some modern brass suppository guns could be heard to crackle if brought in from -10/-20 temps to a warm room. You could literally hear the finish breaking and once cracked its then transparent to water. Artists “stand oil” was made by allowing the oil to air dry, since heating darkens it in a normal oxygenated atmosphere. The oil needs to be nearly colorless when mixing colors so the artist wanted a colorless, or nearly so, oil for the base. It used to be exposed to the sun and air in shallow pans to sun bleach and thicken. But of course it had to be protected from the weather brought inside at night or if there was a possibility of percipitation. Today is done in retorts basically in an oxygen free atmosphere where heating will not darken the oil. Much faster process.
There are a number of very good reasons to use a linseed oil varnish, though in at least a few “schools” of gunmaking spirit varnishes were used. But the properly made soft linseed oil varnish properly made is the most common and most durable finish for a GUNSTOCK. If we read W. Greeners “The Gun” 1835 we see that linseed was a common varnish. His comments on staining maple is REALLY interesting. It can be downloaded from the WWW just don’t confuse it with his son W.W. Greener’s work. I had to dig to find it. “The Gun and It’s Development” will come up a LOT. Since it was in print in many editions for a long time.
Thanks to Bill Knight.
