BLO is an oil stain.

[Chris Padilla]

BLO (Boiled Linseed Oil) is nothing more than an oil that tends to enhance a wood's grain and color.

Basically, it is an oil stain.

It needs 24 - 48 hours to dry, typically.

It is a stain therefore it does nothing to protect the wood...from anything...because it is a stain.

The next argument could be: Fine. BLO is stain...but WHAT KIND of stain? Is is dye or a pigment?

I'd say due to its penetration depth...which I think is deep...it should be classified as a dye.

Go for it. :)

[Scott Holmes]

BLO is sometimes used on cutting boards ::BLO would be an oil finish in my book. Not a good one, and it may impart taste in the food, yuck!

Not protective from much of anything. Cutting boards are usually finished with oil never a film finish in my shop. I use mineral oil (no taste, no smell) which never dries. I also mix it and melt either beeswax or pariffin wax to help it block (or fill) the pores of the wood. It really never "seals" the wood. It needs to be reapplied often.

This is the only "oil" finish I use. I use lots of different finishes made from oil...or varnishes blended with oil (BLO).

Nut and vegtable oils tend to go rancid so I don't use them.

[Pat Barry]

LOL - this should spark some controversy. I'll take the view that BLO is not a stain by intent, but then again, everything stains a bit doesn't it?

[David Christopher]

I dunno if its good or bad, but Ive been putting it on my garden tool handles for a long time, and they are still in good shape

[Chris Fournier]

It is neither, it is an oil finish. There are no suspended colourants to qualify it as a stain. Now you may make a case for calling it a dye because it does impart colour but this would be disingenuous.

I think that like a crumpled BLO soaked rag left unattended the OP is trying to start a conflagration!

Look up "hydrophobic" and you'll see that oil is not a bad idea if you wish to repel water, not great but it is non-polar and water don't like it. BLO as Scott points out is a terrible choice for cutting boards as it has metallic salts in it from the "boiling" process. Poison! Food grade white mineral oil 70 is the stuff for cutting boards and it is readily available and way cheaper to buy from commercial lubricant distributors than it is to purchase from your pharmacy.

Is mineral oil a dye I wonder. For that matter, water imparts a "colour" to wood - is it a dye?

[Howard Acheson]

The reason linseed oil "pops" the grain is because of its natural amber color. Amber, no matter the vehicle will highlight grain or figure. Therefore amber shellac, oil based varnish (which is made with linseed oil) and solvent lacquer will cause the grain of any wood it's applied to to highlight its grain.

I wouldn't call linseed oil either a dye or a pigment stain. It's colorant.

[glenn bradley]

I will expand the discussion to include coffee as a dye.

[Bob Wingard]

The only good use for linseed oil is to preserve axe handles & such. I won't allow that stuff anywhere near my finishing materials. If you REALLY want to see how long it takes it to cure ... put a spoonful on a piece of glass and set it aside. If you're lucky, it'll turn into a gummy mess in a few months. Put it on your wood, and it WILL dissipate/soak in over time, but it's NOT going to dry in a day or even a week. Yeah .. I know .. they used it in the old days ... but then, that's about all they had back then, and it was better than nothing.

I was always taught to apply my final finish ONLY to a clean, smooth surface .. free of rust and oil/grease ... linseed oil does NOTHING to enhance any finish, and can cause adhesion problems & peeling down the road. With so many great finishes available today, I can't believe this crap is making such a comeback. Hopefully, it will be a short-lived one !!!

[Chris Padilla]

I wouldn't call linseed oil either a dye or a pigment stain. It's colorant.

I love it: a colorant! :)

[Scott Holmes]

Bob,

I suspect your experience is with linseed oil, as in raw linseed oil.

Boiled linseed oil will dry out to a rubbery gel with in a few days. BLO is not really boiled, only heated so the added driers will dissolve faster. Lead is no longer used as a drier; now it's probably barium sulfate or titanium dioxide.

[Bob Wingard]

Nope ... my experiences have been with the mis-named "BOILED" variety of linseed oil. Exactly WHAT does linseed oil do FOR you that can't be accomplished with a more sane material ?? As you said, it will eventually turn to some form of gel or sludge, but it will never really dry/cure/harden completely. If that's what you wish to apply your topcoat onto, so be it ... I just have absolutely no use for the stuff.

[John Coloccia]

BLO seems to cure just fine for me. It looks nice and adds a bit of protection to the item you're finishing. When you pick it up, it actually feels like wood. I don't really see what's so horrible about it. Not everything is walked on, sat on, submerged in water, cut on or eaten on. Some things are designed to have a warm, soft glow and feel good when you pick it up to admire it. Items finished with BLO will develop a patina with handling over the years. Some people, myself included, like that for certain items. Maybe I can get it with some other combination of finishes but I use a couple of light coats of BLO.

[Clint Barden]

I've used BLO on quite a few projects. No adhesion problems after a 48 hour dry time (typically using shellac). One thing you have to watch for is bleed back from an open pored wood. If you flood it on thick you can have spots come back after you think you wiped it all up, which can cause adhesion problems.

[Jim Becker]

Nope ... my experiences have been with the mis-named "BOILED" variety of linseed oil. Exactly WHAT does linseed oil do FOR you that can't be accomplished with a more sane material ?? As you said, it will eventually turn to some form of gel or sludge, but it will never really dry/cure/harden completely. If that's what you wish to apply your topcoat onto, so be it ... I just have absolutely no use for the stuff.

Unfortunately, my experience is also different than yours, Bob. I have had no issues with BLO curing or causing any issues with my finishing regimen. I use it specifically for highlighting figure and enhancing the natural color of cherry and other species I work with without using any dye or stains. Occasionally, on decorative projects, it "is" the finish; perhaps with bees wax or not. I have never had a "gummy" problem. Further, there are some times when I use the same "accelerated" finishing technique that Jeff Jewitt wrote about awhile back in Fine Woodworking...BLO applied and wiped off after about 30 minutes; immediate coating with de-waxed shellac and on to my water borne top coats about an hour later.

[Matt Meiser]

BLO applied and wiped off after about 30 minutes; immediate coating with de-waxed shellac and on to my water borne top coats about an hour later.

Really? When was that published--I need to read that article? A friend of mine uses General Finishes Seal-A-Cell, followed by Target's shellac, followed by one of their topcoats but he lests the Seal-A-Cell dry for at least a day at elevated temps and wipes with acetone after that. That's the schedule I used on the kitchen I did last year and it worked great. But I'd love to cut a day from the schedule.

[Bob Wingard]

I'll let the facts & evidence stand on their own ... as I said, pour a little out on a piece of glass .. wait 24-48 hrs as recommended here by many, and see if you can get any topcoat to stick to what's left. If you're happy using it as the only finish, so be it ... I'm not interested in using it that way or any other way for that matter.

[Bob Wingard]

Items finished with BLO will develop a patina with handling over the years.

The wonderful patina of which you speak is more an accumulation of sweat, body oil, and dirt ... all of which were readily accepted by the unprotected, open pores of the wood.

[Pete McMahon]

The wonderful patina of which you speak is more an accumulation of sweat, body oil, and dirt ... all of which were readily accepted by the unprotected, open pores of the wood.

Bob, An English author once stated the only "true" patina was a wax patina. He also went on to bash us by stating "the effete westerner always has a need to wear gloves when finishing"
I agree with you though, a patina is a combination of all of the above along with whatever polishing compound was popular at the time. Look at that witches brew of BLO and turpentine. Many conservators spend an inordinate amount of time carefully removing that oxidized sludge from good surfaces.

[Peter Clark]

I'm suprised nobody mentioned the hydrating properties it brings to the wood.....I my be talking above my pay grade here but doesn't oil in general help to make the cells and fibers in the wood transparent to a degree and that is what bring out the richer and deeper colors?

[Chris Fournier]

If you fire long and hard enough you'll have converts or no one will put there heads up to look!

Sadly I'm a BLO fool and have used it under NC lacquer for pretty much 20 years. No adhesion problems to date. I let it cure first of course.

[Howard Acheson]

>>>> pour a little out on a piece of glass

That experiment will tell you little about the "drying" of boiled linseed oil. BLO is not to be used that way. It's applied, allowed to set for 15 or so minutes and then wiped dry. Used this way is will polymerize (not really harden and cure but forms a soft film) in the wood and on the surface. BLO can be readily coated with an oil based finish before it fully polymerizes as linseed oil is a component of most oil based finishes.

If you are trying to make the point that BLO is a lousy finish, I won't argue. But most folks are using it more as a colorant to "pop" the figure in the grain, not as a final finish.

[Bob Wingard]

"Used this way is will polymerize" ... POLYMERIZE = To react or cause to react to form a polymer. If you choose to believe this without any facts or data to substantiate it ... so be it.

My little experiment is quite valid .. it just doesn't match your preconceived ideas, so you declare it invalid ... nice, open-minded attitude. Further, the notion of top coating it 15 minutes after application is ridiculous. If "popping" the grain involves some of the horrific blotching I've seen using this substance ... I'll pass. If you are a fan of OIL/SHELLAC/TOP COAT or OIL/VARNISH let me ask you this ... how would your finishing schedule address blending the color variation of heartwood/sapwood/solid lumber/veneer ply ???

Try this one ... finish a plank of wood or two using your oil/top coat ... let it "cure" or "dry" or "polymerize" for a few months ... set it somewhere in your house in full sun for a few hours, and watch the oil come to the surface in an attempt to escape. Any substance that has cured/dried/magically turned to plastic will be stable and unable to move in that manner.

[Scott Holmes]

I too use BLO to pop the grain of a project. I don't flood it on and let it soak in... I wipe it on liberally and wipe it off within a few minutes, it only needs to wet the wood, not soak in as you would with an oil/varnish blend finish. I usually seal it in after a day or two with shellac.

[George Neill]

I'll let the facts & evidence stand on their own ... as I said, pour a little out on a piece of glass .. wait 24-48 hrs as recommended here by many, and see if you can get any topcoat to stick to what's left. If you're happy using it as the only finish, so be it ... I'm not interested in using it that way or any other way for that matter.
How often would you pour a little BLO onto a glass-like, sealed wooden surface?

If applied to raw wood, BLO will sink in and dry relatively rapidly, becoming 'one' with the wood.

As others have said, it's good enough to pop grain and can be polished on while still wet. What's not to love about it?

[Henry Ambrose]

Bob is technically correct.

Just because you can't feel the wetness in a coat of BLO applied to wood doesn't mean its dry. Its not dry. If you slap some varnish over it the two finishes sorta meld together and you end up with a hard varnish over some semi hard BLO. I don't dislike it the way Bob does but BLO really does not dry hard. Putting it on glass or metal lets it be exposed to the atmosphere fully so if its gonna dry it will. But of course it does not anymore than it does down in the pores of wood.

BLO has been a valued primer material for a long long time. It soaks in and helps varnish and oil paints bond. BLO has some limited resistance to moisture, but not like a proper varnish. By itself it works well for work bench tops. Its better than nothing in terms of protecting the wood. BLO will keep glue from sticking to your bench top and maybe keep some grime off the surface by being in the wood under the grime.

Overall, BLO is a proven material for some uses but its not everything some would have you believe.

[Bob Wingard]

"How often would you pour a little BLO onto a glass-like, sealed wooden surface?"

NEVER !!! I said to pour a little onto a real piece of glass. I do that just once ... to verify that it will exist in it's present form, practically forever, without EVER drying. The glass is a good overall test to check for physical properties ... if it doesn't dry when exposed to the air, how do you think it will perform once you seal it in with a top coat ??? You might as well use 10-W30.




"If applied to raw wood, BLO will sink in and dry relatively rapidly, becoming 'one' with the wood."

Wrong ... it WILL "sink in" but it will NEVER dry ... as to the "becoming one with the wood" ... now we're getting back to the nonsense about polymerization ... it simply doesn't happen, but if it makes you feel lbetter to believe that ... so be it.

[John Coloccia]

Hide glue turns into jelly when you put it in a glob on a piece of glass, therefore hide glue has no strength because it's like holding things together with jelly...

But whatever. Obviously some people like using it for various reasons. The rant against it seems awfully silly. If you don't like it, don't use it.

[Bob Wingard]

Hide glue turns into jelly when you put it in a glob on a piece of glass, therefore hide glue has no strength because it's like holding things together with jelly...

But whatever. Obviously some people like using it for various reasons. The rant against it seems awfully silly. If you don't like it, don't use it.



DING DING DING ... yet another wrong answer ... hide glue most certainly DOES harden/dry/cure. Added to the fact that now you're comparing apples to oranges ... when can you remember hearing about anyone using hide glue as a finish ???

[Bob Wingard]

Here's a pretty good summary from : http://www.naturalhandyman.com/iip/infpai/inflin.html


Why shouldn't you pick linseed oil as your first choice in a preservative?

Linseed oil has some negatives. Granted, it has been used with some success for many years. But welcome to the modern world! Today, there are scads of linseed oil-based paints and preservatives that expand on linseed oil's good qualities while overcoming (at least to some degree) its drawbacks.

Some of the problems with straight linseed oil, boiled or raw, are:

* Sometimes linseed oil can take forever to dry... or stays sticky or doesn't dry at all!! This is a nightmare situation that happens too often when linseed oil is applied either (1) too thickly, (2) onto damp materials or (3) when the temperature is too cold. Thinning linseed oil with turpentine can help somewhat, but even with thinning it is important to apply thin, multiple coats but allow each coat to dry before applying the next!
* No UV (ultraviolet) light resistance... UV causes more damage to exposed wood than any other factor, destroying wood fibers and setting it up for attack by mildew, fungus, and insects.
* Linseed oil is mildew food... Many vegetable oils are food products for humans... all vegetable oils are food products for mildew! Linseed oil is not completely denatured, so it can encourage rather than discourage mildew growth.
* Linseed oil does not harden sufficiently to offer enough resistance to abrasion to be a suitable deck floor preservative... at least by today's standards. Linseed oil has been used for interior wood floors, but it must be waxed for durability! Waxing an outside deck would be dangerous, even if you hang a "Slippery When Wet" sign!
* Difficult to remove from wood... Multiple coats of linseed oil are gummy and difficult to remove fully for refinishing.

[Jim Becker]

I'll let the facts & evidence stand on their own ... as I said, pour a little out on a piece of glass .. wait 24-48 hrs as recommended here by many, and see if you can get any topcoat to stick to what's left. If you're happy using it as the only finish, so be it ... I'm not interested in using it that way or any other way for that matter.

This really doesn't simulate how an application of BLO to wood will perform. The oil is absorbed by the wood and any excess is removed by the person doing the finishing after 20-30 minutes. There is no "film" and no sticky residue like you get with the glass test. And any oil based varnish or shellac will easily adhere to the wood that's been prepared in this way.

That said, I have no issue with you not liking to use BLO. We have so many choices for finishing products and regimens and each of us is different in our approaches to finishing. That's a good thing.
-------------

Matt, Seal-A-Cell isn't the same thing as using BLO.

[Matt Meiser]

Matt, Seal-A-Cell isn't the same thing as using BLO.

Right, I understand that. He uses Seal-A-Cell because it dries fast but I'm interested in the possibility that that's not required if I use BLO instead.

[George Neill]

"How often would you pour a little BLO onto a glass-like, sealed wooden surface?"

NEVER !!! I said to pour a little onto a real piece of glass. I do that just once ... to verify that it will exist in it's present form, practically forever, without EVER drying. The glass is a good overall test to check for physical properties ... if it doesn't dry when exposed to the air, how do you think it will perform once you seal it in with a top coat ??? You might as well use 10-W30.
You're comparing apples with oranges. BLO isn't applied in the thick quantities that you're describing.




"If applied to raw wood, BLO will sink in and dry relatively rapidly, becoming 'one' with the wood."

Wrong ... it WILL "sink in" but it will NEVER dry ... as to the "becoming one with the wood" ... now we're getting back to the nonsense about polymerization ... it simply doesn't happen, but if it makes you feel lbetter to believe that ... so be it.
It definitely does dry. I have been restoring antique furniture for 35 years from the period that used a lot of oil and it forms a hard skin close to and at the surface of the wood. Maybe your experience is limited or your technique needs reviewing.

[George Neill]

Here's a pretty good summary from : http://www.naturalhandyman.com/iip/infpai/inflin.html


Why shouldn't you pick linseed oil as your first choice in a preservative?

Linseed oil has some negatives. Granted, it has been used with some success for many years. But welcome to the modern world! Today, there are scads of linseed oil-based paints and preservatives that expand on linseed oil's good qualities while overcoming (at least to some degree) its drawbacks.

Some of the problems with straight linseed oil, boiled or raw, are:

* Sometimes linseed oil can take forever to dry... or stays sticky or doesn't dry at all!! This is a nightmare situation that happens too often when linseed oil is applied either (1) too thickly, (2) onto damp materials or (3) when the temperature is too cold. Thinning linseed oil with turpentine can help somewhat, but even with thinning it is important to apply thin, multiple coats but allow each coat to dry before applying the next!
* No UV (ultraviolet) light resistance... UV causes more damage to exposed wood than any other factor, destroying wood fibers and setting it up for attack by mildew, fungus, and insects.
* Linseed oil is mildew food... Many vegetable oils are food products for humans... all vegetable oils are food products for mildew! Linseed oil is not completely denatured, so it can encourage rather than discourage mildew growth.
* Linseed oil does not harden sufficiently to offer enough resistance to abrasion to be a suitable deck floor preservative... at least by today's standards. Linseed oil has been used for interior wood floors, but it must be waxed for durability! Waxing an outside deck would be dangerous, even if you hang a "Slippery When Wet" sign!
* Difficult to remove from wood... Multiple coats of linseed oil are gummy and difficult to remove fully for refinishing.

No offence to the Natural Handyman, but like yours, it's just another opinion. I don't mind you being at odds with BLO either, but you will have a heck of a job turning the people for who it works.

[Jim Becker]

Some really nice (and expensive) furniture finished (http://www.thosmoser.com/) in BLO and wax...and some of it us used heavily in institutional settings.

[John Coloccia]

The other thing to consider is that BLO requires oxygen to cure. It's well known, or at least it should be well known, that it won't ever cure in a blob as oxygen can't get to most of the BLO, and in fact the whole point of the "boiling" process is to promote this curing. So if you don't apply the BLO correctly, i.e. if you're painting it on like house paint, it will never cure and you will have a perpetually tacky, ugly finish.

You know, there's a reason why BLO soaked rags spontaneously combust, and it has everything to do with the exothermic curing process that it undergoes when exposed to oxygen. Next we'll be claiming this is a myth too.

[Bob Wingard]

Maybe your experience is limited or your technique needs reviewing.

Your first statement is absolutely TRUE ... I have extremely limited experience with that stuff, as I refuse to use it !!! The second part is FALSE for exactly the same reason ...

Lemme ask you this ... if it won't dry out in the open air, how can you possibly believe it will dry IN the wood ??? or are we back on the magical polymerization track once again ???

[Bob Wingard]

The other thing to consider is that BLO requires oxygen to cure. It's well known, or at least it should be well known, that it won't ever cure in a blob as oxygen can't get to most of the BLO, and in fact the whole point of the "boiling" process is to promote this curing. So if you don't apply the BLO correctly, i.e. if you're painting it on like house paint, it will never cure and you will have a perpetually tacky, ugly finish.

You know, there's a reason why BLO soaked rags spontaneously combust, and it has everything to do with the exothermic curing process that it undergoes when exposed to oxygen. Next we'll be claiming this is a myth too.

Thanks for making my case ... if it can't dry/cure/whatever in the open air ... it certainly can't do so embedded in a piece of wood with a topcoat over it. Rags soaked in 10-W30 will spontaneooulsy combust as well ... slop some on your next project. Oh ... and it's NOT an EXOTHERMIC CURING PROCESS ... it's an exothermic chemical reaction with oxygen that makes that happen. "CURING" implies a chamical change is taking place ... this stuff will be the same a year from now.

[Matt Meiser]

Some really nice (and expensive) furniture finished (http://www.thosmoser.com/) in BLO and wax...and some of it us used heavily in institutional settings.

Oh come on, you know Moser is a hack wannabe. I mean he doesn't even stain his cherry. :rolleyes:

[John Coloccia]

Thanks for making my case ... if it can't dry/cure/whatever in the open air ... it certainly can't do so embedded in a piece of wood with a topcoat over it. Rags soaked in 10-W30 will spontaneooulsy combust as well ... slop some on your next project. Oh ... and it's NOT an EXOTHERMIC CURING PROCESS ... it's an exothermic chemical reaction with oxygen that makes that happen. "CURING" implies a chamical change is taking place ... this stuff will be the same a year from now.

So it's a chemical reaction with oxygen in which no chemical change takes place. Bob, I respect your opinion but we're just going to have to agree to disagree. It will probably be banned one day anyway.

[Bob Wingard]

OK .. OK .. you guys find fault with the glass test ... try this ...

A paper towel is made from what ??? Cellulose fibers .. wood. Soak a paper towel in your magic finish .. blot off as much as you can .. hang it out explosed to the atmosphere for a year or so, and see if it ever did dry.

[George Neill]

OK .. OK .. you guys find fault with the glass test ... try this ...

A paper towel is made from what ??? Cellulose fibers .. wood. Soak a paper towel in your magic finish .. blot off as much as you can .. hang it out explosed to the atmosphere for a year or so, and see if it ever did dry.
Does it dry? Yes. Does it go hard? No.

Oilcloth used to be made with linseed oil. It dried in the cloth and remained flexible enough to be made into sou'westers, oilskin coats, tents etc. However, if the host is rigid (like wood), then the dry oil will effectively be as hard as the wood it has impregnated.

[Jack Clark]

Well, this is turning into a very informative, albeit lively, discussion. Timely for me because I'm about to start exploring for the best way to finish cherry.

Paul Snyder's website has a pretty good discussion about finishing cherry (www.finishwiz.com (http://www.finishwiz.com)). On the home page click on Cherry. In the section on "Oils and Oil Finishes" he has an example where he used both BLO and Danish oil on the same cherry sample piece with lacquer as a top coat. Interesting comment by Paul: "I don't know which is which and they both look the same."

[Bob Wingard]

Look to Charles Neil's website for a great perspective on finishing woods that are prone to blotching .. including Cherry. I just finishes a large Federal Style Bookcase using his advice and his product. It turned out great with absolutely no blotching .. no color mismatch between heartwood/sapwood/veneered ply. Blotch control coupled with dye is the easiest and most spectacular method I've seen. Oh ... before anyone comments ... I have no affiliation with Charles other than being a satisfied customer.


https://charlesneilwoodworking.3dcartstores.com/Charles-Neils-Pre-Color-Conditioner--Blotch-Control_p_47.html

[Bob Wingard]

Does it dry? Yes. Does it go hard? No.

Oilcloth used to be made with linseed oil. It dried in the cloth and remained flexible enough to be made into sou'westers, oilskin coats, tents etc. However, if the host is rigid (like wood), then the dry oil will effectively be as hard as the wood it has impregnated.

Then, if wood sits out in the rain and gets soaked .. the water is as hard as the wood ?? Linseed oil was a COMPONENT in the manufacture of oil cloth .. not the solitary substance.

[Bob Wingard]

You're comparing apples with oranges. BLO isn't applied in the thick quantities that you're describing.

Here's some more great advice from a "furniture refinish expert" .. .. .. http://www.refinishfurniture.com/finishwood.htm


Linseed Oil, Boiled

Linseed Oil was the choice of the old timers.

I put the boiled after the linseed oil to draw attention to it rather than to indicate that there will be other types covered. The other type is raw linseed oil, it will never dry, but will become gummy and sticky, so be sure to get BOILED linseeed oil if you decide on that kind of finish.

Linseed oil gives a fantastic finish, but you need a year to apply it. The general rule of thumb for a linseed oil finish is once an hour for a day, once a day for a week, once a week for a month and once a month for a year. The finish was usually french polished once a year after that. That's a lot of work.


Lemme' see .... 24 + 7 + 4 + 12 = 47 COATS of linseed oil and it takes a year ... THEN you topcoat with shellac !!!!

[Scott Holmes]

Hi Bob,

Here's what you posted ..Here's some more great advice from a "furniture refinish expert" .. .. .. http://www.refinishfurniture.com/finishwood.htm (http://www.refinishfurniture.com/finishwood.htm)

Well I looked at this site to see what he had to say... (This is a cut and paste from his page right after the part you cut and pasted)

Other Oils

The other oils are much easier to use. Danish Oil and Tung Oil are two popular oil finishes. They are very easy to use and come in clear and in pigmented colors. Just follow the directions on the container, but double the number or coats they recommend. They aren't as durable as some other finishes, but are very easy to repair. If you get a light scratch in the finish, just grab a cloth and apply another coat of the finish and generally it's all taken care of.

He doesn't even tell us which Danish Oil or Tung oil he is talking about... The Tung Oil finish could be 100% pure Tung or it could be Formby's wiping varnish (that doesn't even have a trace of tung oil in nor was the varnish made from tung oil) Now for the "Danish Oil" it is 100% wrong this "Danish oil" is made from (the pastry? the poeple?) NO, it's an oil/varnish blend.

So this expert you are referencing is lumping oils (maybe) and oil/varnish blends into one catagory...

I'm impressed by his expertise and his thoroughness; NOT in a positive way!

[John Coloccia]

That zillions of coats BLO thing is sort of a traditional gun stock finish. I don't agree with the schedule. The proper way to do it if you're going to do that, IN MY OPINION, is to rub a small amount in and wait until it is completely dry and no longer tacky (assuming you're one of the lucky ones for whom BLO actually cures). And then do it again....and again....and again, maybe 20 or 30 times. This sort of relates to another thread of building up a film with BLO. Eventually, you'll end up with a very thin film but it will never build beyond that, as far as I can tell. Past that point, it will either just wipe off as you're applying it or it will be too thick and simply never cure. This process can literally take months. I did it once on a scrap piece just to see what it's like. It's a nice finish, but I can get similar finishes with much less work that are more durable, so I probably wouldn't do it again unless I was doing a reproduction for some wacky reason.

[Howard Acheson]

>>>> Rags soaked in 10-W30 will spontaneooulsy combust as well

Absolutely wrong. Soak a rag in any petroleum based oil, wad it up and put it in an empty metal can. Put a thermometer into the can. Let it set and tell me if you see any rise in temperature or a resulting spontaneous combustion.

For the rag to combust, it requires an exothermic reaction which is due to an interaction with oxygen. Only oils that dry will create and exothermic reaction.

[Bob Wingard]

>>>> Rags soaked in 10-W30 will spontaneooulsy combust as well

Absolutely wrong. Soak a rag in any petroleum based oil, wad it up and put it in an empty metal can. Put a thermometer into the can. Let it set and tell me if you see any rise in temperature or a resulting spontaneous combustion.

For the rag to combust, it requires an exothermic reaction which is due to an interaction with oxygen. Only oils that dry will create and exothermic reaction.


ANOTHER absolutely incorrect "factoid" ... here's the REAL information regarding spontaneous combustion ...


Cause and ignition

1. A substance with a relatively low ignition temperature begins to release heat, which may occur in several ways, such as oxidation or fermentation.
2. The heat is unable to escape, and the temperature of the material rises
3. The temperature of the material rises above its ignition point
4. Combustion begins if a sufficiently strong oxidizer, such as oxygen, is present.



Affected materials
A large compost pile can spontaneously combust if not properly managed.

* Haystacks, compost piles and unprocessed cotton[citation needed] may self-ignite because of heat produced by bacterial fermentation.[1][2]
* Grain dust in a hot metal silo can explode violently, destroying the structure.
* Linseed oil in a partially confined space (such as a pile of oil-soaked rags left out in an uncovered container) can oxidize leading to a buildup of heat and thus ignition.[3][4]
* Coal can spontaneously ignite when exposed to oxygen which causes it to react and heat up when there is insufficient ventilation for cooling.[5]
* Pyrite oxidation is often the cause of coal spontaneous ignition in old Mine tailings.
* Pistachio nuts are highly flammable when stored in large quantities, and are prone to self-heating and spontaneous combustion.[6]
* Large cow manure piles can spontaneously combust during conditions of extreme heat.
* Cotton /Linen. when these materials come into contact with polyunsaturated vegetable oils(linseed, massage oils) bacteria slowly decompose the materials, producing heat. If these materials are stored in a way so the heat cannot escape, the heat build up increases the rate of decomposition and thus the rate of heat build up increases. Once ignition temperature is reached, combustion occurs with oxidizers present (oxygen).

In addition large areas of woodland, shrubland and grasslands during periods of dry hot weather are known to be capable of spontaneously combusting - though the mechanisms causing this are poorly understood. This has been proven to occur via the lifecycle of a variety of plants which require the area to be burned prior to germination.


Additionally ... I have personally witnessed peat bogs in northern Illinois smoldering from spontaneous combustion ... they are about as dry as linseed oil !!!!

[John Coloccia]

Motor oil does not spontaneously combust.

[Bob Wingard]

A simple search found:


From : http://www.westmetrofire.org/index.cfm?main.page=article&catid=15&detailsid=86




Oily Rags--Spontaneous Combustion: Beware of Creating a Fire Hazard

Picture this: It's time to cut the lawn again. You go into the garage to get your mower ready. You check the
mower's oil level and see that it needs some engine oil. So you pour in some oil and wipe up the minor spillage with an old rag. Then you toss the rag into a pail, wheel the lawnmower out of the garage, and proceed to cut the grass.

What's Wrong with This Picture?
If you're thinking that the oily rag you tossed into the pail might be the problem, you're right. Something as
seemingly harmless as tossing an oily rag aside and forgetting about it can ignite a big problem for you. That's
because of a phenomenon called spontaneous combustion.

What Is Spontaneous Combustion?
The Encyclopedia Britannica defines spontaneous combustion as the outbreak of fire without application of heat from an external source. This combustion can occur when flammable matter like oily rags, damp hay, leaves, or coal is stored in bulk. Spontaneous combustion, sometimes referred to as spontaneous ignition, begins when a combustible object is heated to its ignition temperature by a slow oxidation process. Oxidation is a chemical reaction involving the oxygen in the air around us gradually raising the inside temperature of something (like a pile of rags) to the point at which a fire starts.

[John Coloccia]

http://www.cfitrainer.com/Resources/Podcast.aspx?id=August2009

Just listen to it, or read the transcript at the bottom, particularly the part where it says that motor oil won't heat up at all. Then send the International Association of Arson Investigators a nice e-mail explaining how they're wrong.

I like a good discussion as much as anyone, but I'm done with this nonsense and this rudeness.

Peace.

[Chris Padilla]

Folks,

Lets get back to the lively discussion here and keep it friendly. As some can see, I did a bit of editing to keep the peace.

Thanks....

[Scott Holmes]

Hi Bob,

Here's what you posted ..Here's some more great advice from a "furniture refinish expert" .. .. .. http://www.refinishfurniture.com/finishwood.htm (http://www.refinishfurniture.com/finishwood.htm)

Well I looked at this site to see what he had to say... (This is a cut and paste from his page right after the part you cut and pasted)

Other Oils

The other oils are much easier to use. Danish Oil and Tung Oil are two popular oil finishes. They are very easy to use and come in clear and in pigmented colors. Just follow the directions on the container, but double the number or coats they recommend. They aren't as durable as some other finishes, but are very easy to repair. If you get a light scratch in the finish, just grab a cloth and apply another coat of the finish and generally it's all taken care of.

He doesn't even tell us which Danish Oil or Tung oil he is talking about... The Tung Oil finish could be 100% pure Tung or it could be Formby's Tung oil Finish which is a wiping varnish (that doesn't even have a trace of tung oil in it, nor was the varnish made from tung oil) Now for the "Danish Oil" it is 100% wrong this "Danish oil" is made from (the pastry? the poeple?) NO, it's an oil/varnish blend.

So this expert you are referencing is lumping oils (maybe) and oil/varnish blends into one catagory...

I'm impressed by his expertise and his thoroughness; NOT in a positive way by any stretch of the imagination!

[Howard Acheson]

>>>> ANOTHER absolutely incorrect "factoid"

It's amazing you can write and not read.

Your item #1 says correctly "A substance with a relatively low ignition temperature begins to release heat, which may occur in several ways, such as oxidation or fermentation."

Motor oil will NOT release heat as it neither oxidizes or ferments.

Before you spout any more of your drivel, please make the simple test I described previously. If you are able to create ANY temperature rise I would like to know.

None of your "affected materials" are a non-drying oil like motor oil. If an oil does not dry, it does not generate heat.

[Steve Schoene]

I don't know whether applying shellac over BLO after 15 minutes is rediculous, I do know it is a practice recommended in FWW by professional finisher and author Jeff Jewitt. The Taunton FWW finishing special issue available now has a reprint of that article. And, it doesn't take much browsing on the web to see how widely an initial coat of BLO followed by a shellac top coat is recommended, but it will take a very long time to find examples where people report drying or adhesion problems with that sequence.

Obviously BLO is not the sort of chemically inert substance Bob appears to hypothesize. It is oxidizing and polymerizing. Just dampen a paper towel with BLO, wad it into a ball, and toss it into a a half filled trash can. Of course, in a short time you will need a fire extinquisher or the fire department since the chemical reaction that is happening is exothermic and will cause spontaneous combustion. That same reaction is occuring on and in the wood, but slowly enough that the heat created doesn't build to the level that changes into a combustion. The reaction is creating different chemical molecules, some of which do polymerize into heavier molecular weight forms. Eventually they become less fluid--this may take a long time, but it is by no means forever, especially when assisted by the catalysts afforded by the metallic "driers" that make BLO boiled.

Addressing issues of sap color blending etc. is easily addressed with that very little modification. The best practice for such color evening is to use a water or alcohol soluble dye on bare wood. When dry the oil can be applied and everything else can follow exactly as before.

[Jim Becker]

Thanks, Steve and Howie. It's subject matter experts like you that make this community so valuable. Your input, as always, is appreciated.

[Chuck Tringo]

Actually, I've had shop towels...the blue ones from the borg, that ive wiped off BLO with and sat in the sun to dry before putting them in the trash when i was in AZ (to avoid the whole spontaneous combustion thing) they were crusty dry in a few weeks.....must have been faulty BLO....