# The myth of BLO



## ClintSearl (Dec 8, 2011)

One of the more enduring finishing myths is that BLO "soaks" into wood. I've been more than a little skeptical about that idea, so I conducted an experiment to see if and just how much BLO and raw tung oil penetrate different woods. I puddled each oil on samples of white ash, red oak, cherry, and hard maple. After a half hour, I wiped the oils off; and after another hour, re-applied the oils. After another hour I sliced the samples to reveal the edge profile that would show the oils' effects. The open grained oak showed the most penetration at about one millimeter, followed by cherry at around a half millimeter The white ash showed little if any penetration; and the hard maple showed no penetration at all. Between the two oils, the tung oil seemed be absorbed more, which may be accounted for by the difference in molecular weights: 900 for BLO and 250 for tung oil. Because both oils are drying oils, exposure to oxygen begins the polymerization process that impedes the penetration of subsequent coats, which only serve to microscopically thicken the layer of dried oil on top of the wood.

My conclusion is that aside from any aesthetic consideration, there's no functional reason to us BLO or tung oil under a resin finish.


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## bluekingfisher (Mar 30, 2010)

Interesting!


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## Grandpa (Jan 28, 2011)

I agree with you. It will stack up on the surface and protect it some. It is cheap, easy to apply and easily repaired.


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## oldretiredjim (Nov 14, 2011)

Thanks for the useful info.


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## donwilwol (May 16, 2011)

I alway though BLO *under* another finish was for aesthetic consideration.


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## Dal300 (Aug 4, 2011)

In your statistical samples were all woods sanded to the same smoothness?
Also, remember that each of those woods, has a different grain profile.
Was the oil rubbed in? That would make a difference, as would temperature and humidity.
Were these tests done with true tung oil and unadulterated BLO? I have some tung oil that is about 20 years old and it is about as thick as honey. It makes a beautiful finish, but I doubt it soaks in at all.

I have never actually thought about it before, I have never worried about either one being a penetrating oil. I use this stuff for a finish, not for a preservative.

Thanks for the information though, maybe someone can do a more in depth test… Ask the gummint for a grant!


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## wapakfred (Jul 29, 2011)

Yep, I use for color/grain enhancement. Although if using an oil based finish like varnish, that work seems to be taken care of by the varnish.


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## 280305 (Sep 28, 2008)

Craig Stevens got quite different results on white pine:
http://www.woodworkersresource.com/content/shouldyouheatyourlinseedoilbeforeapplyingit/

In this article, he is testing for greater penetration using heated BLO. He finds no difference.


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## PurpLev (May 30, 2008)

was the wood sanded prior to applying oil?

I agree with the assessment that any penetrating oil finish has no benefit under film finish other than for coloring/appearance changes.

these oils are great finish for items that you want to preserve the 'wood feel' but still provide moisture barrier to them irregardless of how 'deep' they penetrate. the concept of 'penetrating' is to differ these from film finishes which produce a hard finish layer on top of the wood, but that does not mean that these penetrating oils penetrate the wood all the way to the core.


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## CharlesNeil (Oct 21, 2007)

Clint , I agree, I have found no sound reason for the use of either in modern day finishes, we have far better oils and products that do as good a job as the BLO and pure Tung oils. I realize alot of folks use and like them for grain pop and enhancement, but again there are far better drying and more durable products. Just my personal opinion


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## JollyGreen67 (Nov 1, 2010)

What if both were cut 50% with a carrying agent, would "soak" rate be any different?


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## wormil (Nov 19, 2011)

Oil applied to face grain doesn't saturate the piece, I expect that is common knowledge. You are demonstrating a property of the wood, not of the oil. Submerge the end grain and it will wick all the way through.


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## rum (Apr 28, 2011)

So a slightly related "experiment" and some other notes.

I turned a bunch of wooden rings from oak about 2.5" across with a 1" hole in the middle (intended to be used as wooden eyes with a rope spliced around them, although the project took a different turn when the fellow I was doing them for got some much larger rope so .. any use for 150 wooden eyes?)" Anyway I soaked them all overnight in a bucket of hardware store BLO mixed with about 20% turpentine. The walls on these are between 1/2" thick and the rim and maybe 3/8" at the center and I can say that the BLO mix soaked all the way through. Granted there was a fair bit of exposed end grain and these were oak (white but still) so these were easy compared to other structures/woods but generally if you really want the BLO to soak in much you have to cut it and soak it a fair bit longer. Some of the rings I got in a hurry on and the ones that were in the mix only 2 hours don't have as good of penetration as the ones left overnight.

Now this is not actually desirable.for a lot of uses. BLO is oxygen curing so in this case the outside "skin" actually prevents the oil in the core from curing for a looong time (up to years if you get it in there deep enough). In this case it has even kept the turps from evaporating entirely (and that's pretty volatile). The advantage of this is that if the piece is scuffed or damaged the oil will re-form a protective coat. This is nice for things like garden tools or outside "ships ware" (like the eyes) where you don't want to be dealing with a film finish that wears/flakes/chips off. For inside furniture you just end up with something that still smells of turps/raw oil and seeps oil out the end grain 6 months/1 year/?maybe longer depending on the wood? later.

This is not to say you can't make a great film finish from BLO or tung, you can - but optimizing for penetration isn't the goal in that case. What you want there is a lot of very very thin layers that have been allowed to thoroughly polymerize between coats (heat also accelerates the polymerization so if you put the piece under a heat lamp you can reduce the time between coats somewhat). If you put it on to thick or don't let each coat fully cure before the next you're left with a horrid gummy mess you'll have to scrape/mineral spirit wash off.

I do use BLO, Tung and other drying oils for some types of projects, but I think its worth remembering there is no "one true" finish and you need to think about what the project will be used for and use an appropriate finish and finishing process based on that.


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## crank49 (Apr 7, 2010)

I was taught that BLO is used as an additive to improve the application properties of other finishes.
And that's how I use it. It will turn a sticky draggy hard to apply finish into a smooth gliding wonder.

Never considered it to be a finish unto itself.


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## unbob (Mar 10, 2013)

Try mixing BLO 50-50 with mineral sprits, that is, if you want more penetration.
Here is an example where I wanted to darken up hard maple on this leg vise. Perhaps a little darker then I needed it to be, after 3 applications of it.


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## Charlie5791 (Feb 21, 2012)

I use BLO and Tung Oil (the real stuff) because I like it. I like the way it feels and the way it smells. For my aromatic cedar flutes, I often use Tung oil cut 50/50 with citrus solvent (again… the real stuff) and progressively work to a final coat of just Tung oil. The flute won't last forever though it will last longer with care from the flautist. I don't like what a harder finish does to the instrument. This is all personal preference.

I also like shellac, and lacquer. I've even been known to use poly (gasp!).
I also like cassein paints (milk paint).

I'm not a finish guru. I don't know all the chemistry behind all of the available finishes. There are guys like Charles Neal who can give expert and knowledgeable advice on finishing questions.

I use lots of different things because I create lots of different things. I was an artist long before I was a woodworker (hence the recent easel build) and as an artist I like the variety. And I like to use tools suited to the job, but I'm not afraid to go off the beaten path and do something considered "different".

Finishes are like the icing on the cake. They should be lovingly applied and some things are just for decoration.

Let's face it. If every cake had chocolate frosting, cake would be pretty boring.


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## ClintSearl (Dec 8, 2011)

I think the assertion that oil mixed with a reducer will penetrate more is wrong. W hat may appear so is the product of differential absorption:the reducer being absorbed more because of its lower relative molecular weight and small molecules that can squeeze between more wood cells; the oil gets left behind. Whether or not oil will wick or be carried by capillary action into the end grain is irrelevant to the discussion.


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## unbob (Mar 10, 2013)

"I think the assertion that oil mixed with a reducer will penetrate more is wrong. W hat may appear so is the product of differential absorption:the reducer being absorbed more because of its lower relative molecular weight and small molecules that can squeeze between more wood cells; the oil gets left behind. Whether or not oil will wick or be carried by capillary action into the end grain is irrelevant to the discussion"

Hmmm sounds like you never used paint.


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## ClintSearl (Dec 8, 2011)

What does paint have to do with the price of onions? Or anything else, for that matter?


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## bondogaposis (Dec 18, 2011)

Penetration is a function of the wood species and the viscosity of the finish. Dense and tight grained woods like hard maple will not take a finish deeply whereas an open pored wood such as red oak will. Any finish will penetrate more deeply if you lower the viscosity through thinning. Whether is be BLO, tung oil or varnish. Another factor is the evaporation rate of the solvents. For instance shellac doesn't penetrate well even though it has a low viscosity because the alcohol evaporates so fast that there is very little time for penetration to occur.


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## Finn (May 26, 2010)

I have often read that BLO makes the grain "pop". In my experience ANY finish makes the grain "pop". I think the reason many think that BLO does, it is because the first application on any finish enhances the look and BLO is usually applied first so the look is changed/improved the most with this first coat.


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## HorizontalMike (Jun 3, 2010)

Hey Bondo,
+10. Earlier this Summer I tried a new-to-me technique with applying shellac and it worked out very well for me. Instead of cutting/thinning the shellac with DNA, I used 70% Isopropyl because it evaporates more slowly. Here in the South Texas heat this little trick came in handy. I would also assume, though haven't tried, that the regular 50% Isopropyl would work as well.

BTW, I have been busy using milk paint on a few Pine projects and in doing so, it pretty much calls for/requires you to wet the surface to be painted FIRST, in order to promote the absorption of the milk paint and promote adhesion. I see no reason that thinning BLO would act any different, depending on wood species of course.
My 2-cents…


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## ClintSearl (Dec 8, 2011)

Facts don't lie, yet the myth won't die. Nyuk nyuk


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## KnickKnack (Aug 20, 2008)

Interesting discussion.
I'm a believer in the "hot oil" method - I use a solar "bottle in bottle" technique for warming it - in my experience it gives a nicer, smoother finish - whether that's because of penetration, or something else, I won't hypothesize.

In my experience ANY finish makes the grain "pop".
Not my experience - especially on fumed oak, oil "pops" the colour more than varnish alone, and Linseed more than Tung. CharlieM1958 posted some great pictures of the difference he found here.

An interesting follow on from this would be - given that "penetration" isn't really happening, what of the whole "you should *not* sand beyond 240/320, since it prevents penetration" debate?


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## 280305 (Sep 28, 2008)

I am amazed at how much great information is in Bob Flexner's Understanding Wood Finishing. He has a section entitled "Oil Finishes and Penetration". Here are two excerpts:

Oil finishes are commonly referred to as penetrating finishes, not so much because they penetrate (all finishes penetrate), but to distinguish them from finishes that harden well enough so they can be built up on the wood. The use of the word "penetrating," however, has led to oil finishes often being marketed as protecting the wood from the inside.

But what good does penetration do, anyway? Very little. You can totally fill a piece of wood with a linseed oil finish, and it will do nothing to protect the surface of the wood from damage…If you are looking for a finish to provide protection to the surface, the amount that a finish penetrates is of no significance.

I like the way that a BLO and wax finish looks. I have used it on many pieces that don't require a lot of protection and I still like how the finish looks after several years.


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## wapakfred (Jul 29, 2011)

No doubt about it, Flexner's book (or the one by Jeff Jewitt, or both) should be required material in any wood shop.


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## Wildwood (Jul 22, 2012)

Agree using any oil under a film finish a waste of time.

Have no use for BLO, because you never know what you are getting from the can. While label may say, 100% Linseed oil can labels and MSDS for most products have many warnings and precautions to follow. Both pure & boiled Linseed oil impart a yellow hue to wood and cause wood to darken sooner.

Still pure penetrating oils do have a place in wood finishing. I am not a big fan of the many oil/varnish blends on the market but like pure oil have a place in wood finishing too.

Bottom line for choosing an oil finish is knowing what it will and will not do. While some wood (carvings) items may only need one application. Most wood items handled regularly will need reapplications.

If building or buying a new house with wood floors or wood cabinets and want a green finish have no problem recommending pure penetrating oil finishes (Linseed, Tung, or Walnut oils). If have family members with allergies might want think about your choices. Tung oil will probably offer more protection than the other two. Adding appropriate solvent may or may not increase penetration into the wood but definitely speeds up drying/curing times.

While penetrating oil finishes do not offer much protection from scratches, repairing a lot easier than film finishes.


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## unbob (Mar 10, 2013)

Ha Ha!
Molecules and onions!
Somehow hard maple is a molecular barrier better then beryllium. 
Of course it will puddle up on very dense wood, its as thick as 20wt motor oil.
Painters know to thin down the first primer coat- for penetration regardless of the wood.
What a worthless thread!
Go ahead and spit your bile, I wont read it or any other BS you post.


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## ClintSearl (Dec 8, 2011)

Anything that "wets" the wood will emphasize the grain. BLO may appear to "pop" the grain more because its muddy amber tone adds color.

Flexner may present himself as a finishing guru, but he doesn't know bupkis about wood and oil together. A chunk of cherry or oak or maple (end grain protected) could be submerged in BLO for a month, and the oil would have only penetrated the face a few wood cells deep.


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## 280305 (Sep 28, 2008)

Clint,

I think that if you looked at what Flexner has to say, you would see that he pretty much agrees with you - even using the word "myth":

It's a myth that our ancestors thought linseed oil was a great finish.
It's a myth that our predecessors expended much effort applying linseed oil when they did use it. Rubbing linseed oil into the wood does absolutely no good.
It's a myth that linseed oil applied in any manner is a durable finish.


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## ClintSearl (Dec 8, 2011)

Thanks, Chuck.


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## ClintSearl (Dec 8, 2011)

The wood samples I played with were sanded to about 150 (very tired 120 on a belt sander) so any nap that was raised by the sanding would be expected to trap more oil than if the sanding were carried to a finer grit.


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## Viktor (Jan 15, 2009)

"Clint, I think that if you looked at what Flexner has to say, you would see that he pretty much agrees with you"

-Don't be ridiculous. Are you suggesting actually reading what you are responding to?


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## Wildwood (Jul 22, 2012)

Think Dresdner, Flexner, & Jewitt admitted to making some mistakes in their earlier books. Pretty sure they have changed their opinions with the times as has wood finishers around the world.

Honestly feel Flexner spot on with what he had to say about penetrating oil finishes in his first book.

Pure penetrating oil finishes are making a minor comeback as wood finishes due to low VOC if watch solvent used. Have to take what manufacturers sales hype with a grain of salt. Times listed for recoating, drying or curing and actual use a bit optimistic.


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## wormil (Nov 19, 2011)

You guys should take this to a milsurp forum.


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## BArnold (May 20, 2013)

I'm sure anyone who wants to poo-poo anything we woodworkers do can "research" it to death until they do so. In my experience, I've used a lot of BLO to enhance grain, especially using cherry. BUT, I also use a bit of common sense. BLO is kinda dense out of the can. SO, I typically mix it 1/1 with naphtha to aid saturation into the wood. Yeah, I tried it straight originally, but it was very apparent BLO needed a little help. 'Nuff sed…..


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## ClintSearl (Dec 8, 2011)

Bill, what happens is the naptha soaks into the wood while the BLO lays mostly on top, but the BLO does spread more easily


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## JGM0658 (Aug 16, 2011)

what happens is the naptha soaks into the wood while the BLO lays mostly on top

That would not happen, assuming BLO is completely soluble in naphta then both would start to penetrate from the surface, as the solution moves deeper into the wood they start to separate, where the naphta would probably go deeper than the BLO. This is a very basic principle used in paper chromatography.


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## Wildwood (Jul 22, 2012)

Bill, just see no reason to use any linseed oil product on cherry wood. Cherry wood will darken with age by itself; film finishes with UV inhibitors may slow down that process. While BLO may pop the grain initially, it will also impart a yellow hue and accelerate darkening process.

Boiled linseed oil is not boiled chemical dryers and solvent added to speed up drying. Linseed & BLO soluble in turpentine and most petroleum distillers; mineral spirits, paint thinner, naphtha, toluene, exylene. 
Naphtha evaporates faster and less oily than mineral spirits. Mineral spirits is better for thinning oils, varnishes, poly, & oil paints.

Naphtha is a stronger solvent mineral spirits, not sure why will often see both listed as components in some oil varnish blends. If have a piece of really old dirty wood furniture wiping down heavy soiled spots with naphtha, then wiping with mineral spirits might save you from stripping that piece.


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## ClintSearl (Dec 8, 2011)

Jorge, speculation does not equal fact.


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## BArnold (May 20, 2013)

The reason to use oil on cherry is to enhance the grain. Been there, done that too many times to consider any alternatives. I use naphtha rather than mineral spirits because it evaporates quicker, speeding the drying time. Thinning BLO with naphtha allows the mixture to penetrate deeper. It works.


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## ClintSearl (Dec 8, 2011)

"Thinning BLO with naphtha allows the mixture to penetrate deeper."

Poppycock! It's just the naptha that's penetrating because its molecules are small enough to get between the wood cells. The BLO molecules are too fat to follow. As I said earlier, it's all about differential absorption.


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## JustJoe (Oct 26, 2012)

Kind of a long response here because I'm hopped up on coffee and I'm a finishing newb with questions…
That's an interesting experiment although the conclusion seems weakly supported. (Soaking in was ruled out, that doesn't mean there aren't any other non-aesthetic reasons for doing it.) 
But I didn't know people were applying BLO so that it would soak into the wood. I applied BLO to my last cherry project. Not because I was trying to get something down into the wood - I don't know or care where it goes once I put it on, I just wanted a look and it provides that look without me waiting until the recipient is so old she doesn't remember who made it. I think it came out pretty good color-wise, no yellows that I can see. 
But these people trying to get finish crammed down into the wood itself - I hadn't heard of that before. Why are they doing it? What benefit are they looking for by having something soak into the wood? Is there anything that provides that benefit besides BLO, with or without soaking in? Or is it just that they are, like me, going for the look and the part about soaking into the wood - myth or not - just comes along for the ride? If the latter is the case, then that's a bit like the whole Twinkies myth. Most of us ate them as kids because we thought they tasted good (what did we know - I also drank Mountain Doo-Doo). If, like the claims, they outlasted Armageddon then that was just a bonus benefit. So if I'm going for a look and BLO gives it to me, then any other rumor - true or not - is just meaningless trivia to me. Soaks into the wood, protects against termites, tastes great with jalapenos…


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## Randy_ATX (Sep 18, 2011)

I would love to have coffee, and maybe even a single malt scotch with you, Joe!


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## lumberjoe (Mar 30, 2012)

Hey Joe! Maybe it's the name, but we think alike. Penetration means nothing. True (drying) oils do not build a film. Therefore they add 0 value to anything I make. I do use BLO on my workbench and plane totes, but that is simply to protect the wood from drying out. I don't kid myself into thinking it adds any protection.

For everyone who is amazed how well BLO pops grain, set up a side-by-side test with dewaxed shellac - especially in heavily figured wood. Nothing brings out chatoyancy like shellac.


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## ClintSearl (Dec 8, 2011)

Ah, yes…shellac opens a whole 'nuther can of finishing myths. Compare a patch of NC lacquer next to shellac, and it'll all look the same.


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## tefinn (Sep 23, 2011)

Clint - Could you cite your references for the molecular weights of the BLO and Tung oil that you used and what brands of each you used?


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## ClintSearl (Dec 8, 2011)

Linseed oil molecular weight: http://wiki.answers.com/Q/What_is_the_Molecular_weight_of_linseed_oil#page3
Brand: Klean Strip

Tung oil molecular weight: Via a Bing search that couldn't retrace.
Brand: Hope's


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## tefinn (Sep 23, 2011)

Thanks Clint. That corresponds to what I could find as well. The TO weight that I found was 276, but that could just be the differences in the natural composition of the oil. I don't use either oil (just never liked them) so can't really comment one way or the other about what is real or perceived in their use. I just found the thread interesting and I'm very curious by nature.


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## JGM0658 (Aug 16, 2011)

Jorge, speculation does not equal fact.

LOL…..Chromatography has been a *fact* for at least 150 years as well as the absorption properties of solutions. Unless you think chemistry is a voodoo. As for your "research" well, I have learnt not to argue with those who believe their results are the final word on any subject. Even when the research itself is flawed.


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## HorizontalMike (Jun 3, 2010)

*It is becoming evident to ME that Clint only supports using ONE product, and we all know how well THAT works.*


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## ClintSearl (Dec 8, 2011)

Wrong brand, Mikey. I only used Kiwi rubbed out with Aqua Velva.


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## lj61673 (Oct 31, 2011)

"It is becoming evident to ME that Clint only supports using ONE product, and we all know how well THAT works."

This is not the first time this same poster has spewed this same brand of fertilizer.

Yawn….......


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## HorizontalMike (Jun 3, 2010)

lj61673, wow "Dot's" alter-ego! Glad you showed up! Well… at least virtually that is.


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## 111 (Sep 2, 2013)

I find BLO to be a great binding agent for mixing my own stains.


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## CharlieM1958 (Nov 7, 2006)

I second everything JustJoe said. I've used and recommended BLO many times, but I've never considered it to be a protective finish, and I've never given a second thought to how deeply it penetrates the wood.

A lot of woodworkers like to keep their finishing as simple as possible, which means a lot of them use wipe-on polyurethane. If you wipe on a coat of BLO before coating with poly, you will, in most cases, get a different look. It's strictly about aesthetic preference, as far as I'm concerned.

Also, BLO alone, buffed and waxed, can be a beautiful finish. Again, though, I don't claim it offers much protection.


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## HorizontalMike (Jun 3, 2010)

Adding to what Charlie says,... Many folks like to finish the totes and knobs of their hand planes with BLO, probably for the tactile feel of the wood on the tool as they use the tool. I find it darkens my rosewood T&Ks but does tend to dry out rather quickly (in a matter of a few days) and then needs to be applied.

FWIW, I have not tried adding a touch of Japan Dryer, though I wonder if that would assist in building up a coating of BLO?


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## Viktor (Jan 15, 2009)

"Bill, what happens is the naptha soaks into the wood while the BLO lays mostly on top"

- A shred of evidence to back up this speculation?

"assuming BLO is completely soluble in naphta then both would start to penetrate from the surface, as the solution moves deeper into the wood they start to separate, where the naphtha would probably go deeper than the BLO."

- Spot on, Jorge.

Clint, you are mistaken if you think that molecular weight/size of BLO is an impediment for it going into intercellular spaces. Those are not even in the same order of magnitude. Porosity is a factor, but wood is not an impermeable membrane for BLO. In this particular case the rate of penetration is dependent on viscosity. Penetration rate of fluid into porous media decreases exponentially with depth of penetration. After a while it may slow down enough that you can consider it ceased for all practical purposes. Solvent will increase this rate manifolds. 
Given enough solvent one could wash BLO entirely through a block of wood perpendicular to the grain and observe a nice break through curve. This has been shown experimentally.


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## bigblockyeti (Sep 9, 2013)

I once tried a built up finish on a curly maple top using BLO and with a reapplication every three to four days (pretty well soaked) for a total of ~ 6 coats, it took nearly a year before the finish dried to the point I where it didn't feel tacky. What a mess and after all that, still no real protection, but it sure did look good.


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## rum (Apr 28, 2011)

bigblockyeti: you can't apply BLO thick, it will take FOREVER to cure as you've found.

HorizontalMike: japan drier can help speed up the drying in some cases depending on what driers the oil has in it. Unless you are starting from scratch making stand oil its probably not going to speed things up a lot - you can try it though but it depends on the existing mix if it will help. Remember that it only takes drops per ounce of drier to matter. The problem is still that you need a lot of thin coats to do anything so you have to basically deal with that fact if you're using BLO.

Joe: the only reason you'd want to soak it in is for something like what I mentioned earlier where you basically don't just want a cured top finish because it will wear off. I saturate most of my yard tool handles with it and yes I generally reapply every year for a top coat but its definitely "in the wood" on most of those (except the ones I got lazy with and didn't fully saturate).

If you take the time to build very thin layers of BLO that is actually the "fastest" (in wall clock time) way to build it into any sort of meaningful finish. It takes a lot of layers and they need to be basically wipe off thin in order to cure properly if you want to actually "build" a finish layer of significant hardness. BLO is oxygen curing so if its at all thick the oxygen won't penetrate and you end up with a gummy mess (waves at bigblockyeti ). This can take weeks to months to do properly and you need to wait at least 12 hours and probably several days between coats so they completely cure (depending on humidity and temperature). If its cold when you put it on it might take weeks to cure.

Raw Linseed (flax) oil polymerizes pretty quickly (< 1 hour for thin coats) at about 450F - I use that fact to coat my cast iron pans with it (above about 465-470 it burns so you can use that to add a little carbon to blend in and harden the polymer if you like living on the edge) . It takes about 9 baked on coats before they start to look pretty and shiny (I'm NOT using BLO here just plain unfettered cold press flax oil). With enough coats you can get it to the equivalent of a non stick pan where eggs slide right off.; that's around 12-16 coats if you don't screw up along the way (once you get to gummy mess here its remove and start over). Below that heat does speed up the polymerization process but I don't know what the curve really looks like - I do know that a heat lamp overnight is generally sufficient with most BLO mixes but doesn't do squat for raw flax oil.

Its most certainly not as abrasion resistant as many other finishes nor as water resistant as some but it is a finish, it does cure. BLO will polymerize so it will build a film finish it just takes a long time and a lot of work.. which most folks don't have the patience for.so they should stick to polyurethane.

rum out.


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