Boiled Linseed Oil

[chas]

Re: Boiled Linseed Oil

There were a set of mahogany handrails 'hanging from the rafters’ in an old boat we bought four years ago. Black stain under cracked varnish and dry.

After wooding them, I wiped on 3 coats of boiled linseed oil, leftovers from a couple of suppliers. Took about a month to dry in a PNW winter. Wiped on semi-transparent oil stain as the wood was light and boring in grain. Covered with a cheap linseed-oil based house deck product that requires twice a year recoat and touchup staining now and again in areas of wear.

Easy to maintain in place, minimal sanding. Looks good from the road, like Cetol. No mildew noted as yet, but I knock on them regularly. / Jim

[Jay Greer]

Re: Boiled Linseed Oil

My wife Anne and I were once guests in the Herreshoff home, known as The Castle at Crocker Park in Marblehead Mass. There was an eliptical dinning room table and was located in what could be called the Family Room. This room was on the bottom floor of LFH's last home. That table was unique in that it was made of cherry and finished with a soft glaze of boiled linseed oil. Skipper paid a young man come, each spring, and apply what is known as a dry shine on it using a mixture of turpentine and boiled linseed oi that was applied with a pad made of cheese clothl. Over the may years of repeated polishing with minutely thin applications of the oil, the table took on the soft glow and look of a fine antique of a by gone era. At the far end, close to the kitchen, was the place where Skipper would slice off a piece of bread, for his breakfast toast, with a special knife he used only for that purpose. Once cut, the bread would then be placed on an antique electric toaster that had exposed heating coils and a spring lever to hold the bread in place, one to each side of the appliance. The intersting point is that there were thousands of tiny scars cut into the surface of the wood in that area. They were incised at roughly a 45deg. angle to the end of the table which, as mentioned was built in the form of an elipse. Most amazing of all was, the fact that every scar was parallel to the adjacent ones and were just as accurate as if they had been layed out with a protractor and a straight edge. We often ate at this table. It was also used by Mr. Herreshoff for the construction of his famous double paddle canoes during the long winters in Marblehead. He must have protected it during its use as a building bench as the only scars were the once that resulted from his carving of bread for toast.
Jay

[chas]

Re: Boiled Linseed Oil

You are a lucky man for that, Jay. I was once a guest in the home built by Myles and Beryl Smeeton when they came ashore in Alberta. To hear stories on some of the artifacts in that house was boggling. / Jim

[Bob Cleek]

Re: Boiled Linseed Oil

My wife Anne and I were once guests in the Herreshoff home, known as The Castle at Crocker Park in Marblehead Mass. There was an eliptical dinning room table and was located in what could be called the Family Room. This room was on the bottom floor of LFH's last home. That table was unique in that it was made of cherry and finished with a soft glaze of boiled linseed oil. Skipper paid a young man come, each spring, and apply what is known as a dry shine on it using a mixture of turpentine and boiled linseed oi that was applied with a pad made of cheese clothl. Over the may years of repeated polishing with minutely thin applications of the oil, the table took on the soft glow and look of a fine antique of a by gone era. At the far end, close to the kitchen, was the place where Skipper would slice off a piece of bread, for his breakfast toast, with a special knife he used only for that purpose. Once cut, the bread would then be placed on an antique electric toaster that had exposed heating coils and a spring lever to hold the bread in place, one to each side of the appliance. The intersting point is that there were thousands of tiny scars cut into the surface of the wood in that area. They were incised at roughly a 45deg. angle to the end of the table which, as mentioned was built in the form of an elipse. Most amazing of all was, the fact that every scar was parallel to the adjacent ones and were just as accurate as if they had been layed out with a protractor and a straight edge. We often ate at this table. It was also used by Mr. Herreshoff for the construction of his famous double paddle canoes during the long winters in Marblehead. He must have protected it during its use as a building bench as the only scars were the once that resulted from his carving of bread for toast.
Jay

Ah, yes, but LFH was a bachelor! I doubt any married guy would ever get away with slicing bread on the table top! Life can be so much simpler and civilized when one doesn't have to worry about accommodating the ladies!

As I said above, I never use anything but 50/50 turpentine and boiled linseed oil for finishing wood when I don't want a high gloss finish and particularly if I expect it to get some wear. It penetrates and dries quickly and, to my nose, at least, has a pleasant aroma. I don't use cheesecloth, though. An old tee shirt will do. (Being sure to hang it out of doors to dry thoroughly in the wind after use, so as to avoid spontaneous combustion!)

[S B]

Re: Boiled Linseed Oil

I'm sorry, but this is mostly incorrect.

Raw linseed oil does not polymerize, or harden. It remains soft, which is what allows subsequent coats (and, unfortunately, moisture) to penetrate. It's not until the chemistry is changed by either heating of the raw oil, or (the modern version) adding chemical driers, that the linseed oil will harden by oxidation.

There's nothing wrong with the yaaarrrr look of boat soup, but it's not a lot of protection. The pine tar helps, but if you get too much on, it rubs off on clothes and sails, and bags. With hot weather, it can seep and really make a mess. In small amounts, though, it's not a huge problem, but it's also less protection.

If you're going to argue finishes with a fellow like Flexner - who's devoted a career to understanding them - you'd best bring more to the discussion than, "I believe". Why do you believe he got it wrong? What point, exactly, are you taking issue with? What expert opinion, or testing data would you cite to support your opinion?

Raw linseed oil will most certainly form a dry film, without the addition of dryers or heat treatment.

[David G]

Re: Boiled Linseed Oil

Raw linseed oil will most certainly form a dry film, without the addition of dryers or heat treatment.

Raw linseed oil will cure/harden somewhat with exposure to oxygen. Boiled linseed oil (which in modern times means adding salts of heavy metals - cobalt, manganese, or zinc - not actually boiling) will cure harder. Both cure very slowly in comparison to most other finishes, but the boiled will absorb oxygen quicker (that's the point of those added chemicals) and cure faster. When they dry, both leave a satin, not gloss, sheen. Neither will cure very hard, and neither cure hard enough to allow the buildup of a film of protection on the surface of the the wood. That's the distinction between a 'penetrating finish' and a 'film finish' like shellac, varnish, lacquer, or water-based finishes. Therefore - neither are very resistant to moisture, chemicals, etc. Of all the finishes - except wax - linseed oil is the least protective.

[lesharo]

Re: Boiled Linseed Oil

Don't Question Flexnor Because He's an Authority?

Hardly. Judge him on what seems to be the merit of what he's saying' using what ever means you have at your disposal, common sense hopefully being one. The fact that one talks or talks a lot or talks loudly or especially talks professionally says very little about the validity or the value of what he has to say. I wold say, listen and question and then decide. Especially question authority. Or supposed authority. Some people love to talk and love to give advice and even make money at it. Whether they are right or wrong has little to do with it.

There were some good points made here from experience, some maybe just passing on what they've heard. In the end, you just have to make up your own mind.

[David G]

Re: Boiled Linseed Oil

lesharo,

I don't think I said "Don't Question Flexnor (sic) Because He's an Authority". What I said was - if you're going to argue with someone who knows as much about finishes as he does, you'd best bring more than 'I believe'. Believe based upon what?

Having done finishing of various sorts for nearly 40 years, I can offer up plenty of anecdotal experience, and - I hope - a fair bit of common sense. So... I'd agree with most of your second paragraph. Question what you're told. Compare it to your personal experience. Find out what other knowledgeable people say on the matter. But I begin to take issue where it seems to tip over into - My Opinion Is As Valid As Yours... No Matter How Little I Actually Know (aka the Democratic Fallacy).

In my experience, I've found very little to quibble with Flexner about. That's why I cite him. If you have some specific issue to take up with something he claims... make your argument. Cite your personal experience. Back it up with research by others. There are other sources one can find. Use inductive and deductive logic to extrapolate the data to reach a conclusion. But don't try and suggest that Flexner should be disregarded because 'he's some sort of self-appointed expert'. That's just ignorant and self-defeating.

[Bob Smalser]

Re: Boiled Linseed Oil

Cosmo Lengro’s Boatbuilding Voodoo Hall of Fame
One-liners taken from a decade+ of reading boatbuilder’s on-line forums.

15) Raw linseed and tung oils are great moisture barrier coatings. (Idle boredom was probably the reason man since the ancient Egyptians has added fillers, proteins, driers, pigments, hardeners and poisons trying to improve them, the end result being paint.)

[Wayne Jeffers]

Re: Boiled Linseed Oil

Good one, Bob!

Wayne

[S B]

Re: Boiled Linseed Oil

Raw linseed oil will cure/harden somewhat with exposure to oxygen. Boiled linseed oil (which in modern times means adding salts of heavy metals - cobalt, manganese, or zinc - not actually boiling) will cure harder. Both cure very slowly in comparison to most other finishes, but the boiled will absorb oxygen quicker (that's the point of those added chemicals) and cure faster. When they dry, both leave a satin, not gloss, sheen. Neither will cure very hard, and neither cure hard enough to allow the buildup of a film of protection on the surface of the the wood. That's the distinction between a 'penetrating finish' and a 'film finish' like shellac, varnish, lacquer, or water-based finishes. Therefore - neither are very resistant to moisture, chemicals, etc. Of all the finishes - except wax - linseed oil is the least protective.

Boiled linseed oil means boiled linseed oil, steamed to be exact. It is the bottom of the barrel as linseed oil goes, steam extracted after the top grades have been separated from the flax seed. Cobalt, manganese and zinc are not labeled as heavy metals. The metalic compounds act as catalysts speeding up the oxidation process. Linseed oil forms a flexible film, not impervious to moisture, that becomes brittle with age. Shellac, varnish(mixture of drying oil and resin), Lacquer(nitro celulose resin) harden by the evaporation of solvent. They are impervious to moisture, forming continuous films, that reflect the nature of the origional resin, usually brittle.

[Bob Smalser]

Re: Boiled Linseed Oil

Linseed is a natural drying oil, the problem being that without heat treatment or chemical additives it can take decades to dry.



This is a circa 1910, straight-grained walnut rifle stock out of a common tree crotch with probably the finest natural patina I've ever seen. The reason is the original owner applied one teaspoon of raw linseed once a week, well rubbed in. After a few years and decades a gorgeous, hard finish.

The problem on these old linseed-finished guns is linseed in the inletting. Between the metal sweating with temperature changes, the poor sealing ability of linseed, petroleum oils applied to the metal seeping into end grain, and the propensity of raw linseed to attract mold, the inletting on these fine old heirlooms is often punky and literally non-functional. Fortunately the soft, saturated wood can usually be Dremeled out and epoxy added so as not to be evident from the outside yet restoring the firearm's functionability.

[S B]

Re: Boiled Linseed Oil

On an absorbent ground, such as a gun stock, the film only dries at the surface, much the same as paint skins over in the can. Much of the staining is caused by nondrying oils entering the wood through surfaces not covered by the drying oil, such as the mating surfaces between metal and wood. The same problem would arise had the gunstock been rubbed with varnish once a week. Just because your grandfather did it that way, doesn't mean you have to. 50 years of doing something wrong, is not 50 years experience.

[Bob Smalser]

Re: Boiled Linseed Oil

My point is that while it needs to be kept away from precision inletting, few other finishes bring out the best in the wood as linseed.

A classic varnish finish results from wetsanding open-grained woods like mahogany with boat soup consisting of linseed, turps, Japan Drier and a touch of pine tar. The sawdust-linseed slurry fills the open pores and the polymerized bits of linseed provides a bit of sparkle beneath the varnish.

[S B]

Re: Boiled Linseed Oil

I'm not argueing that linseed oil isn't the cat's ass, just that it is what it is and not be expected to do the impossible.