Hey there, Blackdog! I'm not holding back any info on finishing, but just that the gears are moving slooowwly. You know, my family has a history of varmint hunting for a few generations (it's in the blood), and I'm trying to make up for some lost time from my nonshooting years. I've been reading up on gunstock finishes on the Varmint Hunters Association website. My finishing experience has been with stringed instruments and basic woodworking, so this is fun.
There are some good recipes out there for finishes, and I'm mainly interested in Tung oil, which is boiled Linseed oil and mineral spirits. To recap, the mineral spirits have evaporated out of the Tung oil, leaving behind the Linseed oil. The drying time has gotten way too slow, so the plan is to try and reconstitute the stuff.
Well, I decided to use Naptha instead of the Mineral spirits in various concentrations. I've been doing 2 handles lately: a paring knife for the wife, and a 25" AK Panawal handle that has been re-engineered (as per the thread). The little knife has done great with a mix of 3 parts old Tung + 1 part Naptha. But the big AK has been very slow in drying, and it could be because the mix was closer to 4 + 1. Once this is no longer tacky I'll go to weaker concentrations. I might try the mineral spirits mix later just to see what happens.
The recipes on the VHA site call for less oil in the highly acclaimed Linseed / Mineral spirits / Polyurethane mix of EQUAL parts (I'm not using this because I don't want a glossy finish). This tells me I've got too much oil in it. I do all my mixing in plastic syringes in small amounts to be exact, and the Naptha makes the rubber plunger sticky. I doubt this affects the chemicals, but it's a little strange.
Another odd thing is these drying and penetrating agents can escape thru plastic containers over time, which must be why my Formby's bottle has been sucking in and the level getting lower much faster than the usage.
Sorry about the lack of pics, as I'm somewhat computer challenged...and maybe a little chemically deficient, too!
Thanks for asking, and I'll post again....Dan