Just some observations on the SKS stock.
All these pictures are clickable to get a larger version, btw, and have been throughout this series of articles.
There is something a bit troubling about the finish on the SKS gunstock that came with this carbine. This isn't the first gun I've gotten for cleaning, its about my fourth but worst so far in that this one has been packed with cosmoline. Still getting the obvious stuff out of the way goes a long way to seeing just what went on with this particular specimen at the arsenal in Yugoslavia. In that picture there is a thousand words, but in particular it allows me to show the basic difference in finish even through the cosmoline.
The upper handguard is of tightly denser grain wood which is part of what I'm seeing, but the other part is that it has a more even texture to it for the finish. Notice that the closest match in color, not texture, is in the forward part of the grip that has a white paper towel under it to put more light on it, and that aft of that the part with less reflected light is darker. Now the handguard also has what looks to be a good (if somewhat spotty here and there) finish which I take to be BLO (boiled linseed oil). Thus there are firstly tonal gradations in the wood that are different and, secondly, the upper finish while applied well is not applied evenly. There is a little bit of that left to right between the more open grain to where it narrows down. The grip part of the stock is of a darker toned wood and still covered in cosmoline...
Now this image shows something very similar along the entire buttstock:
The flash artifact in both these pictures would lead you to conclude that it is the cause of the tonal differences, but that is not the case. From grip to where the butt plate would be there is a significant difference in tonal variation visually in the entire stock. After much handling and examination this does not appear to be a variation in the wood but in the finish. The finish is thicker in the front and thinner to the rear, thus darker to lighter.
Next up are some actual droplets of congealed finish on the buttstock. My picture taking ability is awful but there is only one significant droplet but also some other areas where tonal darkening increase and touching along those areas gets a slight rise and fall with the darkened areas. You also get some tacky cosmoline on your fingertips.
Then there was the struggle to get the barrel/receiver assembly out of the stock. Cosmoline, as a lubricant, should be able to do some of that, yes, and with larger amounts more of that sort of thing, but this was stubborn beyond all belief.
Beyond that there is that tackiness on the exterior part of the stock, which has had the most goings-over of antique restorer. There are a few parts that are close to actually being dry on the rear of the stock, that is blotchy in feeling by fingertip. This is not something that a light rag will pick up, but that your fingertips will. The further you go towards the grip area the more of the tackiness you get and lots of it. In reference this has had just as much wipe-on/wait/wipe-off/go overnight/rub off that the Mosin-Nagant had for its entire process.
Now reading up on BLO is a fascinating topic as regular linseed oil does not set up quickly without having some additives put in with it. Basically it remains tacky for decades. That is hard to do even in a relatively backwards Communist country as boiled linseed oil is done in huge batches and the ability to get raw linseed oil through an arsenal is just about nil. That does leave the cure time for BLO, however, the time it takes to set and harden. That has an overnight to basic cure and a week to nearly done and a month to fully cured. Thus you can do a bit of sanding and apply a second coat after an overnight, but the entire thing doesn't become a finish until at least a month sets in.
I am coming to a conclusion that is very interesting: the arsenal did not let this stock have its proper cure time and put it in a vat of cosmoline before the cure was finished.
Points for this are: the somewhat uneven finish appearance, hardened drops of BLO, uneven darkness with thickening of the finish, and the tackiness. Of all of those the most worrying is the tackiness, and not just for handling reasons.
Consider that BLO when heated and mixed with other oils can form a lacquer, that is something that will form a much harder finish that is more resistant than just BLO itself. With that said there are also accelerants that get added, things like turpentine, to speed up the drying process of a lacquer. Heat will do it to, and this is a problem that folks shooting Mosin-Nagants have with cosmoline seeping into the magazine area and mixing with the carbon and any firearm lubricants used to create a lacquer coating in the firing chamber. That can get so bad your rounds won't chamber. A good lacquer solvent will get rid of that but the problem is from the cosmoline, itself.
So if you have an uneven proportion of BLO to cosmoline, say one part to fifty parts, you get a very weak lacquer that has no accelerants and has lost heat in the first few hours after coming out of the vat. That creates a substance that is at once much thicker than BLO or cosmoline as it is setting up, but doesn't have a good enough mix to become a full lacquer. BLO after mixing with cosmoline might not even set up at all as it tries to cross-link with some very, very, very long chain hydrocarbons. Some of it that is closest to the wood pores will not get much of that effect (becoming a 'finish') but being cross-linked out means that it never sets up or dries. As far as I know there is NO accelarant that will do this for cosmoline-based grease finishes... are there such things, even?
The stock will get the full treatment to drive out as much of the cosmoline via pore action as possible, and there may even be some break-up that will happen to let the surface finish finally get severed from the longer mixture. As it stands, however, the stock is heading into the 'refinishing' category. Now since stocks were sent unfinished to troopers and they did it their own ways, that lets me have a lot of leeway on what I can do with the thing. As this is Beech wood, it should have a nice light tonal quality to it if done with just a bit of care... I like BLO finishes, don't get me wrong as I have a gallon of the stuff available, but having seen some Finn Beech stocks done with shellac... and that is an available and traditional finish for the region, too.
Time will tell. I had hoped to get this done and free up the workshop as its not a great idea to be woodworking with lots of volatile chemicals in the air. But if it is still tacky on the outside in a few days, then I will look into stripping the wood bare and refinishing it.