Why Linseed Oil

S

ss Dragonfly

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Nov 9, 2006
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I am wondering why boiled linseed oil is often called for in treating wood handles. Does linseed oil offer some special properties when applied to wood or are there other things that work as well that may be substituted.

Thanks in advance,
Shane
 
Oils offer some penetration and conditioning of wood. Help prevent the wood from overly drying out, deforming and cracking. Drying oils such as boiled linseed oil can also be built up to provide some amount of actual coating.

Oils are also very easy for the average user to apply with no special tools or know how, and very easy to touch up.

There are a wide array of oils that fit this description. Tung oil, boiled linseed oil, Danish oils, etc are very similar. Even non drying oils like plain mineral oil offer some protection, sheen and waterproofing.

Varnishes sometimes overlap with oils a bit. But they tend to be thicker, and more coatings than penetrating oils. Shellacs and lacquers are solvent based coatings with minimal penetration. There are also epoxy-like coatings and cyanoacrylates. All these coating type finishes can be quite good. However, they often take more preparation, skill, and equipment to apply.
 
Like shecky said, linseed is a drying oil. After it's applied it will over the course of a week penetrate the surface and harden. Sucessive coats will eventually build up a lusterous and durable finish. This is opposed to mineral oil/general lubricating oils which (hopefully) never dry out and harden. The boiled part is important as unboiled linseed oil takes a VERY long time to dry to a non-tacky finish.

Oil finishes aren't "required" on knife handles, but in the case of some (like tramontina's wooden handles) they can greatly extend the useful life of the handle. The wood as finished from the factory is often very dry and prone to splitting as there's no protection from swelling and shrinking due to changes in humidity. Depending on the finish you're trying to achieve and the wood in question, you can use almost anything. For tight grained, oily woods a simple waxed finish or no finish at all works well. On woods like walnut and other open grained hardwoods it's often a good idea to put a few coats of oil on to seal them from the environment.
 
Research has shown that linseed oil is one of the best preservatives for wood. The oil will over time both oxidize and polymerize and form a plastic.It is not however a waterproof coating for wood.
 
mete said:
Research has shown that linseed oil is one of the best preservatives for wood. The oil will over time both oxidize and polymerize and form a plastic.It is not however a waterproof coating for wood.
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That's why you melt in some pine pitch...
 
For making Staffs and such, I like to do a base coat (or 2)with boiled linseed oil, and then use Tru-oil Gunstock finish (5-10 coats or more) for protection.

I have used the Tru-oil without the linseed oil base coat as well, and it penetrates nicely too.

sp
 
Great information guys, is linseed oil readily available over the counter? I would like to refinish a small axe handle I have and need to pick some up. Any other particulars on refinishing axe handles made of hickory?

With regard to the oil prep, does it come boiled or must I prepare it? If so, if you don't mind, what is the preparation process?

Thanks in advance, you folks are a "Font of Practical Knowledge".
Shane
 
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You can get boiled linseed oil at Lowes etc - no prep needed just apply/ dry /reapply dry etc.

If you are re-finishing an old handle might want to get some fine grit sandpaper and give it a good once over before applying & then take a moist papertowel and do a couple of passes to get any dust out of the way - let it dry for a few minutes and then aply the L oil.


Good luck!

sp
 
Here is a link with some good articles on oils and oil finishing.
http://www.wwch.org/Technique/Finishes/Finishing.htm

These days the "boiled" linseed probably isn't literally boiled, but has had metalic driers added to it to speed its setting. Boiling linseed can be dangerous as the boiling point and the autoignition point are the same.

I don't know if you can get it there, but Terebene is used to help old paint and oils to set. Its handy stuff if you want to make your own oil finish.

Danish Oil is a mixture of thinners, oils, varnish and driers. It will penetrate fairly easily, and sets faster and more easily than plain boiled linseed. The problem with setting oils is that once it has set, additional coats can't penetrate into the wood. If you want deep penetration you have to keep it wet for a while.

I like Tru-oil, but its hard to keep it without it drying out. If you aren't going to use a lot, don't remove the foil, just poke a hole in it, the lid it comes with isn't remotely airtight by itself.

For your axe handle you could use multiple coats of Danish oil, or boiled linseed, or a mix of boiled linseed, beeswax and terebene. If it is true refinishing from bare wood, I would either use the Danish oil as a base, or thin the others with some white spirit to help it get into the wood. Don't worry too much, on an axe you won't need to worry about as many things as if you were finishing a nice bit of walnut for a knife or rifle.

Best of luck:)
 
Linseed has been used for a long time - mainly because it was a cheap by-product that wasn't suitable for lubrication or cooking but had other properties that made it useful as a preservative. (Window putty is basically clay + linseed oil). IMO Tung oil does a better job on wood as it seems to soak in better and is more water repellant
 
ss Dragonfly said:
Great information guys, is linseed oil readily available over the counter? I would like to refinish a small axe handle I have and need to pick some up. Any other particulars on refinishing axe handles made of hickory?

With regard to the oil prep, does it come boiled or must I prepare it? If so, if you don't mind, what is the preparation process?

Thanks in advance, you folks are a "Font of Practical Knowledge".
Shane[/QUOTE

i like to take a piece of broken window pane and scrape the old finish off from the handle. then apply 3 parts boiled linseed oil and 1 part turpentine to the handle. usually three or more coats.
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Ankar Sheng said:
Whats the practical difference between raw and boiled linseed oil?
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raw take YEARS to fully cure, Boiled takes a few days.

a lot of painters (canvas ) use raw linseed to mix with their paints, to prolong the drying pocress and when it does dry it seals in the colors.

I use boiled linseed oilm Tung oil and turpentine to treat all my axes, tomahwks and walking sticks. I have a bucket i leave the entire ac head in when i'm not using it, a quick wipe down with a rag (soak it in water after!) and my tols are well preserved, and tghe ax heads are tight as a ......
 
It comes boiled and clearly labeled as such. They don't actually boil it these days, it's put into large vats and oxygen is injected which induces polymerization. Drying agents are sometimes added as well to speed up the curing process.
 
Comes boiled - recommend thinning it with mineral or natural turps if you want to leave it in to soak - I still thing tung oil does a better job though
 
And, as always, bear in mind that linseed oil produces heat as it dries. This is the kind of oil that if you leave it on rags wadded up in the trash can spontaneously combust. I just rinse the oil out with water and dish soap before tossing the rags.
 
"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."
 
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