Furniture and stringed instrument varnish is usually a poor choice for firearms...
Yes of course, but I've found no other person with a video that shows the actual process of heating and mixing oils/extras for wood finishing.
The "Modify as seen fit for outdoor implement use.
" may have been too simplistic a directive to those who are actually going to do something besides open cans and smear finishes onto wood. But that's what I meant by it-not to parrot a fiddle-maker, but to learn from the observation of his process. Also to appreciate that there are some other rare folks out there doing it the old way. I included the video here to help us (of lesser finishing experience) advance our understanding of finishing oils, modifiers, solvents, resins, varnishes, shellacs, poly-wanna-be-i-ain't-got-times-for-dat, and et cetera.
Instrument finishes are all about being "slightly indoor durable" without deadening any resonance of the tonewoods. Also to be pretty and repairable. So thin, light, and hard, is what I expect from them.
And that video is also the only other place I've noticed pH modification via the lime--as you speak of when making Actual Boiled Linseed Oil (NBO). But also there is a solution of potassium hydroxide used in that process. As far as I can tell there are no checks for the balance achieved, but maybe the recipe never called for that. Maybe the margin of error is big enough that the recipe covers variations in the solutions.
I do know that KOH solution strength can be tested by buoyancy (
Foxfire, IIRC). I don't imagine pH testing kits were in the shoppes of olde.
If I could find evidence of other folks mixing up or modifying Linseed oil, I'd share that too. We know that "Boiled" linseed oil is not, but should be, and can be with care. I'll call it
Natural-Boiled Linseed Oil (NBO).
Home cooking is best.