Gunstock Oil Finishing

[snyper]

Wood Finishing with Oil
by Ray Lancon

There is a certain amount of mystery revolving around oil finishes, with
good reason. A good oil finish, while fairly easy to accomplish, is rare
to find these days. It's a very low tech process which, when done well,
produces a magnificent finish, but it is a time consuming procedure which
requires considerably more effort than simply brushing or spraying on a
topcoat such as varnish or lacquer. Primarily, an oil finish is IN the outer
surface of the wood rather than ON the surface, which is the property that
makes it such an attractive finish.

Originally, boiled linseed oil was the material of choice, and it was typically
mixed with equal parts of thinner, such as turpentine, and occasionally
small amounts of varnish and/or bee's wax were added. Linseed oil
is an oil extracted from flax, and the term 'boiled' is misleading but very
important. Boiled linseed oil is not actually boiled, but rather oxygenated,
a process that changes the polymer structure of the oil, which causes it to
eventually dry and harden. Raw linseed oil will never dry, and does not
make a good finishing material. Even boiled linseed oil dries quite slowly,
and the addition of varnish or driers is common these days to speed drying
and provide faster build of the finish. Tung oil is another commonly
available finishing material, though more often than not, off-the-shelf tung
oil finishes are not true tung oil at all, but rather a mixture of the materials
I've previously mentioned. Tung oil has become a somewhat generic term,
encompassing many varieties of oil finishes.

My favorite oil finish is Watco(tm) Danish oil finish, the ingredients of which
are a closely guarded secret -- it's safe to say, however, that it is also a mixture
of oil, varnish, thinner, and driers. It's my favorite for the simple reason that
it's been around for many, many years, and the manufacturers have in general been
quite obstinate about not meddling with the recipe for the stuff, which makes it
far more predictable than most finishes.

After several years of working with Watco and other oil finishes, it
became quite apparent to me that the manufacturers were more interested
in promoting and marketing these products with the focus upon 'quick and
easy finishing' as opposed to helping the user achieve striking results.
An old finishers' adage concerning the application schedule for oil
finishes went as follows:

Once a day for a week
Once a week for a month
Once a month for a year
Once a year forever after.

Well, that's a lot of work, and most people are not interested in maintaining this
schedule, nor are most furnituremakers delighted at the prospect of having a
piece in the finishing process for three months or more before it can safely be
delivered to the client. Many manufacturers of oil finishes have addressed this
problem by advertising their products as a 'wipe-on, wipe-off' finish, leading the
user to believe that a simple one or two-step application is all that's required...
and while that will provide a finish of sorts, it won't be anything to get excited
over or write home about. In fact, the next time you find yourself in the wood
finishing section of your local paint, hardware, or home center and see any finish
product that boldly proclaims that you can now have a beautiful hand-rubbed finish
in 2 hours, you have my blessing (and my gratitude) if you just smirk and walk
away. Fortunately, the correct process to achieve a gorgeous, truly hand-rubbed oil
finish lies somewhere between the two extremes. Try this procedure once, and
you'll probably never be able to see one of those 2-hour products again without
laughing out loud.

If you really want to spite the manufacturers, a common recipe for home-brewed
oil finish is to mix equal parts of boiled linseed oil, turpentine or mineral
spirits, and plain oil-based (gloss, not satin) varnish or spar varnish (spar
includes some UV inhibitors). The finishing procedure is the same.

The object of oil finishing is threefold:
1) Seal the wood.
2) Fill open pores and grain.
3) Make it lustrous, without a notable surface film.

Poorly done oil finishing, which we see a lot of, accomplishes the first
objective, but not the other two, leaving a finished piece that is fairly
well sealed, but entirely lackluster and uninspiring. In my opinion,
this is what you end up with most of the time by following the manufac-
turers' instructions.

So I re-wrote the instructions. Specifically, I re-wrote the instructions for
Watco Danish Oil finish, because it's the product I personally use most
often, but other oil finishes are very similar, and the method works well
with tung oils and other oil finishes.

Drying times are approximate, and at least in my shops, Watco dries more
slowly than the container's instructions would lead you to believe. It's not
imperative, but it is desirable that previously applied coatings be thoroughly
dry before moving on to the next step, which in my environment generally
takes anywhere from 1 to 3 days.

----- IMPORTANT SAFETY NOTE -----
Note that any rags and cloths you use are very susceptible to spontaneous
combustion. This can occur when the solvents attempt to evaporate from your
rags but do not have sufficient air to evaporate into. I won't make any
recommendation concerning what you should do with your finishing cloths, nor
will I take any responsibility should your shop catch fire. Watco and other
manufacturers recommend submerging used cloths in water to prevent
spontaneous combustion, and this is certainly the most foolproof method.
My own method is to take my rag(s) and drape it somewhere near my work
piece where it will get plenty of air circulation, and allow it to dry there. That
way I can tell how dry the finish on the wood is by checking to see how stiff
the rag is.

Also note that I recommend Watco Satin Wax in the final steps of the finishing
procedure. This is a liquid wax (which allows you to wet-sand the first wax coat),
and as of this writing, is available in either natural (white) or dark (walnut).
Use the color that most closely matches your wood. If your piece falls some-
where in between (i.e., mahogany), you can mix the two colors to achieve
an appropriate intermediate color. Watco itself is also available in colors, but
I've never found a need for anything but the natural variety.

My finishing method is not endorsed by Watco or anybody else -- indeed, if
they've ever heard of me it would be quite a surprise. Use it at your own risk
and discretion. I will guarantee, however, that following it closely will
provide a finish that equals or exceeds French polishing in terms of that
unquantifiable quality that causes people to seem unable to keep their hands
off of your work. In my mind, a well-done oil finish is one of the most
sensual things on earth.

And now (finally...):


WATCO FINISHING INSTRUCTIONS

1. Disregard the instructions on the container.
2. Sand surfaces to at least #280 grit. Remove dust (you may not be able to
see it, but there is loose sandpaper grit mixed with the dust which will
interfere with subsequent operations.)
3. Wet surfaces with WATCO Danish Oil. Keep wet for at least one hour,
reapplying at ten minute intervals. If your workpiece is small enough,
place it in a 'bath' of the oil and 'baste' it.
4. Wipe off all excess oil. Especially with large-pored, open-grained woods
such as walnut, ash, mahogany, oak, etc., oil will seep from the pores
for several hours. Check the surface at least every 1-2 hours, wipe it
down, and repeat until no more seepage occurs.
*Note: Obviously, it's best to start finishing early in the day.
The oil seepage will be lessened if your workpiece and your
environment are cooling rather than warming up.
5. Allow the piece to dry for 48 hours (or more).
6. Wet the piece with oil again, and keep it wet for a minimum of 20 minutes.
7. Wet sand with #400 grit. Sand with the grain, and add more oil as necessary
by wetting the surface of the sandpaper. Spend some extra time and
oil on the end grain, where the oil will be absorbed much more readily.
Wet sanding causes the wood's pores to absorb a slurry of oil and dust. When
adding more oil during the wet sanding, take care not to wash away this slurry.
If this step isn't done thoroughly, the end grain will never seal, and will never
produce a sheen similar to the rest of the piece.
8. Repeat step 4. (There should be little seepage this time.)
9. Allow to dry thoroughly.
10. If the surface is still very flat (dull), repeat step 7 with #500 grit.
11. Wet sand with #600 grit, wipe off, dry for 48 hours. By now your piece should
have that 'baby's butt' smoothness, and the wood's pores will be filled
and level. If not, you took a shortcut somewhere, so repeat this step again
after allowing the finish to dry thoroughly.
*Note that you can continue wet sanding, (which is actually polishing) with
finer grits for as long as you like. For very fine work, I frequently continue
up to 1000 grit and finer. Just be sure to let the piece dry between each
grit.
12. Apply WATCO Satin Wax. To enhance the sheen slightly, you can wet sand
with #1000 grit paper or a fine 'Scotch-Brite' pad. I don't use or recommend
steel wool, as it shreds easily and generally makes a really hideous mess. The
wax is difficult to rub out if it's been allowed to dry too completely, so work
on manageable-sized sections, or get a helper for this task. If you've been
adequately anal-retentive about making sure the wood's pores are completely
filled, you can use a paste wax rather than the Satin Wax with very good results.
The reason I recommend Satin Wax is because it re-dissolves itself with subsequent
applications.
13. Let dry (about 10 minutes). Rub off excess wax (soft cotton cloth), buff (rub
hard) with a clean, soft cloth. I don't recommend power buffers.
14. Dry for 8-12 hours, reapply wax, and repeat step 13.
15. You're finished! Satin Wax can be reapplied any time to polish & clean previously
oiled/waxed surfaces.

Original article can be found in this link: Wood finishing with oil

[snyper]

A Classic Oil Finish
By Frank Whiton

The following is my gun stock finishing method using the wet sanding technique. I must give credit to Phil Pilkington for teaching this procedure to me. I attended a week long school presented by Phil that covered stock layout, checkering, his finishing method, and acid bluing. If you buy Phil’s Gunstock Finish you will receive an instruction booklet with these basic instructions. The wet sanding finish is used by most custom gunsmiths today with some differences from gunsmith to gunsmith. Not only can this procedure be use for gun stocks but will give a table top or jewelry box a beautiful finish.


The first decision is what oil finish you want to use. The worst choice would be raw boiled linseed oil. BOL does not have the correct dryers in the oil and if you get into a hurry you will have a mess. A better choice would be a commercially prepared finish like Tru-Oil, Len-Speed, Waterlox, or Pilkington’s Classic Gunstock Finish. There are many other finishes out there and many are used with good results. I have never use Tru-Oil with good results but many have. For me it dries too fast for a wet sand-in finish. Len-Speed is not the same oil that it was years ago and I have not used it for many years to finish a stock. The problem with both of these oils is they are linseed oil based. Linseed oil does not have the water proofing properties that Tung oil has. There is no doubt that Linseed oil gives a beautiful finish and we will use some in our finish. Waterlox and Pilkington’s Classic Gunstock Finish have a Tung oil base. If you are finishing a stock for wet conditions I would stick with a Tung Oil based finished. Pilkington’s Classic Gunstock Finish doesn’t have the water proofing ability of Waterlox. When I finished rifles for Alaska I used Waterlox as the filler base and then applied the Pilkington’s Classic Finish over the Waterlox. You can use Waterlox for a complete finish and it will be quite nice.

Now let’s get down to work on finishing a rifle stock. You need to finish all inletting and shaping of the stock. The sanding should be done down to 220 or 240 grit paper. If you have used an aggressive rasp or a bastard file, make sure all damaged wood is removed. The best sanding paper I have found is the dark gray wet or dry paper used by body shops. It is usually Silicon Carbide and has a low friability.

Aluminum Oxide has more friability and will cut faster but you don’t want the grit to breakup and put impurities into the finish. Now the stock is ready for the finish. The first thing to do is to LIGHTLY fog the stock with water. A fine mist sprayer held a good distance for the stock will do. Do not soak the stock. Set the stock aside and let it dry. If you want to speed it up you can evaporate the water using a hair dryer. Don’t use the hair dryer until the whiskers on the stock has risen and don’t burn the stock. Your nicely sanded stock will now be very rough to the touch. This is called by some as “Raising the Grain”.

The next step is to remove the whiskers from the stock. Removing the wishers is done by locking them into position and cutting them off. We do this with our finish of choice and the wet or dry paper. I will describe the procedure using Pilkington’s Classic Gunstock finish. You need a small glass bowl like those used for mixing spices before you put them into your recipe. You need some glass eye droppers from the drug store. A good source is your local college science lab if they will sell them. The stock finish is diluted with Mineral Spirits by a one to two ratio. The eyedropper should be able to suck up about an inch of finish or mineral spirits with no problem. Start with 10 droppers of finish and add 20 droppers of mineral spirits into your glass bowl and mix well. Now soak the finish into the stock. I use a rubber glove to apply the finish with my hand. You could use a brush or your bare hand. If you run out of finish just mix some more using the 1 finish to 2 spirits mixture. Soak in all of the finish that the stock will absorb and also to the inletting. Now set aside the stock and let it dry for 24 hours. In most cases it will dry sooner but you want to be sure it is totally dry before the next step. After it has dried the whiskers will be locked into the finish. We will remove the whiskers in the next step.

After our 24 hours of drying time we can began the wet sanding of the stock. The purpose of wet sanding a stock is to fill the pores. Most Walnut and most other gun stock woods have fairly large pores. We will fill the pores with finish and sanding debris. Wet sanding is done using 320 grit wet or dry sandpaper. Before you start to apply more finish you need to cut up some 320 sandpaper into pieces 1.5” X 2”. I usually cut a couple of dozen at a time. Any left over can be used next time. Make sure you cut the paper with scissors instead of tearing. A lot of times I cut them with a razor blade. Now mix some of the finish with the spirits at the 1 to 2 ratio. Wet a small portion of the stock with the mixed finish. A small portion would be 4” to 6” of the for-end.

The sanding is done very lightly in a straight line. Never sand in circles. You just glide the sandpaper over the stock. You will feel the paper cutting. You can use a backing to the paper. My favorite backing was a draftsman rubber eraser that is 1” wide, 3” long and about 3/4” thick. I grind a radius on one of the long sides of the eraser making a nice 90 degree round edge. Using this as a backing I can sand flats and up to round edges. Most of the time I will use my fingers as the backing. If you sand too hard you will pull the finish out of the pores instead of filling them. This is a key factor. Sand just hard enough to feel the sandpaper cutting. Always use a backing when sanding two different materials that butt up together like the recoil pad or grip cap. As you sand the small area you will see the finish and the sanding dust combining together and forming what I refer to as “Muck”. You just want to see a small amount of Muck that just looks like dirty finish. Before using a new piece of sand paper I wet it in the finish so I am never sanding a dry area of stock. Now wet another small area and continue to lightly sand and continue this process until the whole stock has been wet sanded. Change sandpaper squares very, very often and keep it wet with the mixed finish.

With experience you will be able to feel the sandpaper cutting and will know when it is time to change. If the area you are sanding seems to get dry just dip the sandpaper back into your finish or just dab a finger into the finish and add a little to the area you are sanding. Do not sand long in one place. It is almost like rubbing down the stock with a rag. If you don’t sand enough or use enough oil you will not build up any Muck. Sanding a complete stock will take less than an hour. With experience you can sand one in 40 minutes. You should use up nearly all of the 24 squares of sandpaper you cut. When you are finished sanding the stock will have some areas still wet but the first sanded parts may be quite dry. Now cover the complete stock with your mixed finish using only your fingers. Don’t rub it; just wet it down so all of the sanding Muck is wet and the stock is gleaming. Now set it aside for the finish to start to dry out again. You don’t want it dry but you want the finish to thicken to a paste consistency. This will take 5 to 15 minutes according to how hot it is in your work area. After you do the next step a couple of times you will know how dry it should be.

After the wet stock has set and the muck is starting to firm up but is not dry, we will remove the muck using paper towels. The paper towels should not be the type you use in your kitchen. They are way to absorbent. The best paper towel I found was the shop towels used to wipe grease off of your hands. They were a brown/tan color with some texture. The cheaper towels are better because they are not as absorbent. Take a paper towel and wad it up so it is all winkled. Start rubbing in a circular pattern rubbing off the muck from the stock. Do not rub hard unless you have let it dry too much and then it will be more work. Do not polish the stock just wipe off the muck turning the paper towel to keep new towel wiping off the stock. Use new paper towels as needed. Don’t be concerned if a little bit of the muck is missed. You want to remove the muck but if some is left it will be removed with the next wet sanding. Do try to get at least 99 percent. You probably won’t see any filling of the pores at this time but you will as you repeat the procedure. Now set the stock aside and let it dry for 24 hours

After the 24 hour drying time you will repeat the procedure again using the 320 grit paper.

After another 24 hour drying time you will repeat the procedure again using the 320 grit paper. This time you need to be careful to remove all of the muck. This is where you have to use reflected light to view every bit of the stock looking for any residue and that all the pores are full. If you don’t have a dull glass smooth surface, with all the pores filled, then repeat the procedure a fourth time after the 24 hour drying time. Usually three wet sandings with 320 grit sandpaper is all that is needed.

After the last wet sanding with 320 grit sandpaper and the stock has set for 24 hours, repeat the procedure using 400 grit sandpaper. Continue to lightly wet sand and to lightly remove the muck just as you did with the 320 grit sandpaper. Be very careful when removing the muck with the paper towel. If you rub too hard you will pull the finish out of the pores.

After another 24 hour drying period repeat the procedure using 600 grit sandpaper. This is a polishing step and you just need to float the paper over the stock. This time when you remove the muck use a clean cotton flannel cloth and do not rub in circles. Rub along the length of the stock and remove every bit of the residue. The muck at this stage is not much more than just finish. Don’t wipe hard enough to polish the stock. Just use the cotton cloth to remove any finish.

Now we wait 4 days and we then checker the stock or do the following rub down. I mentioned earlier about using Linseed Oil on the stock and we are at that point now. This finish has been based on using Pilkington’s Classic Gunstock Finish. If you bought some of his oil you should have also got a bottle of his Classic Linseed Stock Rubbing Oil. Even if you have use a different finish you can use the Linseed Rubbing Oil for a finish. This oil is used in future years to renew your finish. To finish the stock we take some of the Rubbing Oil and add some rottenstone to make a past. We lightly rub the stock with the rottenstone and oil mixture covering the stock very quickly with out rubbing the stock with any pressure. Set the stock aside for 30 minutes and then lightly remove the finish with a clean cotton flannel cloth. The finish is now done. The wood will have a beautiful luster to it but it won’t be real shiny.



To add more shine to the finish we can add more Linseed Rubbing Oil. After the rottenstone rub procedure and the stock has set for 4 days you can apply a thin coat of Rubbing Oil on the stock. Just use enough oil to cover the stock. Set aside for 30 minutes and then wipe off with a clean cotton flannel cloth. Don’t rub, just remove the wet oil. You will leave a very thin coating of the linseed oil and it won’t attract dust. Repeat this procedure every 4 days until you get the shine you want. Keep in mind that the purpose of using the sanding-in procedure is to put the finish into the pores and not get a big build up of finish onto the stock. If you add many coats of the rubbing oil you will add to the surface build up of the finish. This same procedure can be use at a later date to renew the finish.

The above finish will give you a fantastic finish but there is another way to get a beautiful finish with less work. When you have finished wet sanding the stock with 320 grit sandpaper and you have the pores filled to suit you proceed with the 400 and 600 grit sanding as directed above. Now instead of the rottenstone apply the Linseed Rubbing Oil and let it set for 30 minutes. Wipe off the oil with a clean cotton flannel cloth. Wait 4 days and repeat the step with the rubbing oil. It is now done and you will like it.

If you want a real quick finish you can go straight to the rubbing oil after the 320 grit sanding has filled the pores and keep adding the rubbing oil until you have the finish you desire. Remember that you must wait 24 hours between wet sandings and you must wait 4 days between coats of Linseed Rubbing Oil. The waiting period is to insure the previous coat of oil has completely dried.


Original and complete article with pictures can be found in this link: A Classic Oil Finish