Oil Finish

[JCKelly]

In deciding how to finish a walnut stock I might suggest looking at how it was done pre-WWII. After all, your stock is intended for a gun that has been obsolete since the Grant administration. To me  it seems inappropriate to use modern fast-drying finishes on a muzzle-loading rifle. The Modern Gunsmith, Vol. I,  by Howe. Chapter XII covers in detail of how a professional finished walnut in an earlier time. The procedure varied depending upon just what type of walnut he was using.

One may download Volume I for free at:
http://fliiby.com/file/34571/njz9evs5k7.html     

The term "Boiled linseed oil" doesn't quite mean what it says these days. Howe used real, raw linseed oil (you can't get it at the hardware) with real turpentine (also not available at hardware or paint stores). One finish involved mixing a pint of raw linseed oil with a half pint of turpentine, and heating to the boiling point. Apply with a swab. This is for an arm to see hard service, say in the tropics.  After several heatings the oil became thicker.

Howe mentions how linseed oil was processed, some three or four score years ago. What it "boils" down to, is if you want good quality raw linseed oil in 2011, then get what is called "Cold Pressed linseed oil" from an artists' supply house.  Oil already thickened with heat is available, same source, as "Stand Oil". Likewise real turpentine distilled from pine, no odd chemicals added, is also available.  There are several types or grades of linseed. I would suggest staying with Cold-Pressed, possibly Stand Oil.

Background on artist oils may be found in The Artist's Handbook of Materials and Techniques, Fifth Edition , by Ralph Mayer.

Artists' oil is expensive when compared with hardware store varieties, but not at all so versus commercial stock finishes.

For example: Lin-Speed $9.99  2 0z (59ml) dries in 2 to 3 hours. Advertised as "The Famous 'Real' Kettle-Boiled Linseed Oil."  Source - brownells.com
 I might beg to differ with the ad, but that's just me.

Winsor & Newton Cold Pressed Linseed oil $10.71 for 2.5 oz (75ml)
Winsor & Newton Stand Oil $6.30  2.5 oz (75ml)
Winsor & Newton Distilled Turpentine  2.5 oz (75 ml) $3.29, 16.9 oz (500 ml)  $11.54

Source - dickblick.com

Real linseed oil contains no driers, so it requires some time to finish a stock. Hand rubbing is part of the process.

[Rasch Chronicles]

Thanks for the information!

One thing though, I did find several years ago a couple of gallons of raw linseed oil at one of the Borg cube stores. In addition they had real honest to goodness turpentine... At least I think it says pure turpentine; I'll check when I get back home.

Best Regards,
Albert “Afghanus” Rasch

[davec2]

I purchase various materials from this outfit and have had good luck with both the company and the materials including various types of linseed oil and their aged turpentine.  Better prices than many places as well.  I have made an excellent leaded fill oil and finishing oil (per Dan Phariss and Mad Monk information) using the varnish makers linseed oil and lead carbonate.  I make it on a hot plate in a glass Erlenmeyer flask about 200 ml at a time and it takes less than a half an hour.  The aged turpentine is used with the finish oil just as Dan describes using his turpentine left to oxidize in a shallow dish.
It is made by bubbling air through pure gum turpentine in the presence of manganese naphthanate acting as catalyst in sunlight for 10-15 days. The solution has been filtered to remove the insoluble catalyst.

http://www.woodfinishingenterprises.com/coating.html

[Rasch Chronicles]

I knew saving those Erlenmeyer flasks would come in handy for something other than mixing shooters during Halloween!

Thanks again Amigo!

Best Regards,
Albert “Afghanus” Rasch
The Rasch Outdoor Chronicles: George Washington, President and Fisherman

[JCKelly]

Just a post-script. Read Howe, lots of stock finishes, stains, etc.

Cold-pressed linseed oil is much better quality than the hardware stuff, and is preferred for both art and for a real oil gunstock finish. The artists say the cold-pressed oil makes a tougher film, less inclined to embrittle with age than the "hardware stuff". J.V. Howe just says it is the finest linseed oil for gun stocks, as opposed to commercial raw linseed oil..

All linseed oil is made by pressing flax seeds to extract the oil. The artist grade is "cold pressed", a wasteful process which does not remove all available oil from the seeds.

 Commercial linseed oil is made by pressing the seed hot, at very high pressures. What remains is extracted by solvents, and (most of) the solvent is then evaporated. Since the early 1800's this process has been used to give a much better yield than does just pressing the seeds at room temperature (cold). This is the raw oil sold at the hardware or good paint store. The assorted impurities in it cause it to embrittle with age, more so than does the cold-pressed oil.

Soaking walnut in raw linseed oil makes the best finish to bear up under abuse, such as for a military stock. TPH tells me all US gunstocks were so treated right up through WWII. Soaking the walnut also hides the grain, so is not done to a figured piece of walnut for your sporting rifle or shotgun.

Old-fashioned "pure gum spirits of turpentine" is made by distilling the gum tapped from living pine trees. That grade is available from artist supply houses. Hardware store turpentine, or "steam distilled", is made more efficiently by steam-cooking a mash of ground stumps, limbs, slash and such forest waste.

Pure Spirits of GumTurpentine reacts chemically with the linseed oil, a process which binds available oxygen to "dry" the oil, even deep in the wood. Linseed oil does not "dry" by anything evaporating, but by reaction with oxygen to form a polymer. Sunlight helps this, moisture slows it down. Store your turpentine away from sunlight.

Oil from flax seeds makes a better film than does anything else, e.g. walnut oil. safflower oil, tung oil. Your gunstock might not have to last you for centuries, you might like the best oil finish to survive weather while hunting.

[Rasch Chronicles]

JC,

Thanks for the clarification. My Chambers New England Fowler should be waiting for me when I get home, and certainly want to do right by it! I appreciate all the information you have gathered for all of us.

Best Regards,
Albert “Afghanus” Rasch
The Rasch Outdoor Chronicles™
Best Hog Hunting in Florida!!

[Simon]

Basically because I had the material from painting projects, I used stand oil mixed with pure turpentine. cobalt dryer, and copal resin.  I don,t have a formula, I just mix as I would with paints.  Of course  the more stand oil you use the more of the other products you mix in.  I use about a half ounce of stand oil, 4 to 5 drops of cobalt dryer,  8-10 drops of turpentine, and about a quarter ounce of copal resin.  I let it stand uncovered overnight and then apply by rubbing in  a drop on my fingers. 

The more copal you use, the shinier the finish will be.  A lot of Cobalt does not seem to make it dry faster, but you should try adding a little cobalt and turpentine until it drys as you want it to. 

One thing that is different for Cobalt than for Japan dryer for those that have used it, the Cobalt drys from the top down , while the japan dryer drys from the bottom up.  I haven,t found much practical difference in the amount of time needed to dry, just that the Cobalt mix will not allow you to rub as much as the Japan dryer.

When dry, the finish is hard.  How ever I haven,t had it on anything long enough to know if it will crack like an old oil painting will.  I have wiped it with a damp cloth  and haven,t  found any problems.  A good wax can be used over it when dry.

[Ron Brimer]

John Bivins  had a original Deckert  that had been found in  Penn, the thing was wrapped in wax coated linen, Bivins said when unwrapped ,"it was shiny as the grill of a 56 caddy. When the finish was analyzed ,it was Shellac and Linseed oil. The pure stuff, form bugs . You can get the real thing from
 www.woodworker.com.   Oh yea  just so you guys get to know me, I could be the unibomber. look me up on the CLA site.  Take care
 RON B 

[Dphariss]

Basically because I had the material from painting projects, I used stand oil mixed with pure turpentine. cobalt dryer, and copal resin.  I don,t have a formula, I just mix as I would with paints.  Of course  the more stand oil you use the more of the other products you mix in.  I use about a half ounce of stand oil, 4 to 5 drops of cobalt dryer,  8-10 drops of turpentine, and about a quarter ounce of copal resin.  I let it stand uncovered overnight and then apply by rubbing in  a drop on my fingers. 

The more copal you use, the shinier the finish will be.  A lot of Cobalt does not seem to make it dry faster, but you should try adding a little cobalt and turpentine until it drys as you want it to. 

One thing that is different for Cobalt than for Japan dryer for those that have used it, the Cobalt drys from the top down , while the japan dryer drys from the bottom up.  I haven,t found much practical difference in the amount of time needed to dry, just that the Cobalt mix will not allow you to rub as much as the Japan dryer.

When dry, the finish is hard.  How ever I haven,t had it on anything long enough to know if it will crack like an old oil painting will.  I have wiped it with a damp cloth  and haven,t  found any problems.  A good wax can be used over it when dry.

Is this copal resin already mixed with oil? Copal will not mix with oil cold if my information is correct. It, like the other resins require heat to combine with the oil.

Cracked paintings.
We have to remember that the materials and varnishes used by artists are not what was used by gun makers. The gunmakers used softer, cheaper resins that on FIREARMS were more durable. The harder varnishes and the clear finishes needed or used  for oil painting were not needed. The old "boiled" oil varnishes were too dark to use for color mixing. So air thickened stand oil that is nearly transparent was used. It cost far more to make but was needed for the colors used in oil painting.
The boiled oil was cheaper and worked better for firearms finishes giving better color to walnut etc and producing finishes that would not check or crack on the wood if the oil/oil varnish was properly made.
Really hard resins are hard to combine with the oil and a finish that is too hard will be water proof until is checks or cracks.
Those here that are enamored with the hard "water proof" varnishes and/or synthetic finishes need to finish a piece of maple or walnut with the stuff with a slight build up on the wood as a varnish film would be. When fully cured drop a 50 caliber round ball on the finish from 36"  or so then examine under magnification.
If its cracked the finish is unsuitable for firearms use.
A soft oil varnish/good boiled oil finish will not crack. It will adhere to the wood and conform to the dent unless very extreme.
Once a hard brittle finish is  dented and/or cracked water as liquid or vapor pours through the cracks at will.

Dan

[Simon]

Dan, I don't know anything about pure copal resin.  The bottle I have is made to use with artists oils, is a thick liquid, and mixes quite easily with paints and can be thinned with turpentine.  It is used with oil paints to add  shine and durability.  I don't know how long it has been used as a paint additive.  Some of the projects I have used it on are more than 5 years old and have shown no sign of cracking.

I placed the information here because JC Kelly referred to stand oil in his post.  I don't  If it makes as good a finish as boiled oil,  but it is what I have and I will continue to use it.  Time will tell if it holds up with use.

Mel

[Dphariss]

Dan, I don't know anything about pure copal resin.  The bottle I have is made to use with artists oils, is a thick liquid, and mixes quite easily with paints and can be thinned with turpentine.  It is used with oil paints to add  shine and durability.  I don't know how long it has been used as a paint additive.  Some of the projects I have used it on are more than 5 years old and have shown no sign of cracking.

I placed the information here because JC Kelly referred to stand oil in his post.  I don't  If it makes as good a finish as boiled oil,  but it is what I have and I will continue to use it.  Time will tell if it holds up with use.

Mel

Seems its already been made into varnish it seems So it will easily combine with oil.
What you are doing is sound practice, more oil makes for a more elastic finish and the resins increase the water resistance.
I was just curious as to how you were combining the copal into the oil.

Dan

[Dogshirt]

Check for flax seed oil at the health food store. It should be pure, and MUCH cheaper than art supplies.

[kutter]

Stand Oil will dry the best of any of the linseed oils in my experience.
It's made by heating raw linseed at some extremely high temp in a special apparatus that allows no air into the mix.
Artists use stand oil for alot of their color mix and a final coat as it dries quicker but not so quickly that you can't work with it. Plus it doesn't yellow like the raw product.

It would be my choice to make an oil based varnish with, which is all that's being done.
The other choices, raw and boiled linseed either barely harden or harden very slowly on their own.
Addition of dryers helps of course.
They offer almost no water resistance alone either.

Instead of an oil varnish, I use a simple shellac finish alot. A spirit varnish by old accounts. Easy to apply, and was still used right into the 20th century by most of the American gun mfg'rs.

I do use the Windsor Artists Linseed Oil for a drop or two rubbed out coating over the top of the finish. It drys quickly and gives a nice glow to the work. The little bottle lasts a long time,,longer if you didn't knock it over and spill some of it one time...

[Stophel]

All I can say is that you boil turpentine with your oil at your own risk!!!

When oil catches fire, you get max, foot high flames that are relatively easily snuffed out.  When turpentine catches fire, you get six foot high raging flames of death.  Choose wisely.   

[Dphariss]

Raw oil will never dry once it soaks into a stock.
I have an rifle I can use as proof if anyone wants to stop by.

Stand oil is thickened linseed oil that is as colorless as it can be.
Painters do not want a dark brown oil to use as a mix for colors for obvious reasons. Its intended for a far different use and is made in an entirely different process, or was back it the day, than "boiled" oil for stock finish.
Modern Gunsmithing books, to be brutally frank, are almost useless in the stock finishing chapters. People have to remember that commercially made "linseed oil" was available by the 1870s or so if not well before. While it was somewhat better perhaps than some of the oils of today it was still not stock finish as used by the gun makers of the 18th century or even most of the 19th. The industrial revolution brought about changes in the paint industry as well as other things and much of the knowledge of finishing gunstocks with Linseed oil was largely lost by the early 20th century. The attempts to use modern commercial oils resulted in Linseed oil getting a bad name as a stock finish, in America anyway. The English still knew/know how to do an oil finish from what I understand.
When the Gunsmithing books start talking about using raw oil I simply stop reading the section and move on. They are continuing another myth and usually if you read they don't use this for finish. They use something else, usually a solvent laden varnish of one kind or the other.
LS oil needs to be combined with drier of some sort to be really usable as a stock finish. Without driers the oil will still be weeping out of the stock decades later. In the case I cited above since 1942 and a rag placed in the cleaning kit recesses in the stock will still soak up linseed oil to this day...
So I won't be using raw oil for stock finishes unless I get some driers in it and then test.
I guess I could try making some oil from cold pressed oil, it would be more traditional. There is so much variation  in the boiled oils available, seems like the brands available change regularly and then the oil has to be tested after I make it to see if it really works as it should. I made some awhile back then just put it in jars and when I got around to using it realized the oil needed more driers.

Various metal driers, often oxides, were/are used, historically they are usually "cooked" into the oil.
You can find cobalt and Japan drier being sold on the same rack as stand oil and I don't think its an accident. Paintings need to dry to be durable... SFAIK stand oil has no driers historically, today I could not say.
Boiled oil, historically, is darker since it darkens in contact with the air when heated.
Stand oil used to be thickened by setting it in the sun in shallow pans, this required constant watching so the oil was not exposed to moisture. This made it VERY expensive compared to heat modified oil.
Today it is heated in sealed retorts so no oxygen is present to darken it, or so I understand.

I don't bother with stand oil and have no idea what its drying properties are. But I doubt it will dry as fast as a true boiled oil will. Store bought boiled oil is basically much slower drying than oil prepared for stock finish.
The reason I will not bother with stand oil is that its the wrong color for stock finish. Clear finishes were not used back in the day and today tend to make a poor looking stock compared to dark drying oil.
A GOOD linseed finish or a GOOD linseed oil gunstock varnish DOES NOT CRACK. Period. It may wear off but it does not crack. Be it on a longrifle or on a 1880s Ballard. The film will not even crack when its dented.
But if enough stuff is added and the oil content is reduced and/or excessively hard resins are used the finish may loose is elasticity and then check, peal or flake.
Moderate amounts of resins will reduce or eliminate water spotting.
Dan