Boiled Linseed Oil Drying Time

P

pearle

Guest
My Christmas Candleboxes (http://www.sapfm.org/forum/index.php?topic=1534.0) are proceeding apace. I expect to start final finishing (top coat) next Monday. I'm making a Lonnierob Millardbird version (combining ideas from Rob Millard's and Lonnie Bird's versions): four each in cherry, mahogany, and walnut. The cherry ones I want to finish naturally with boiled linseed oil and a shellac or lacquer top coat. I've never used BLO on an actual project before, and a friend tells me he doesn't believe the BLO will dry adequately in the 5-6 days between now and the time I need to apply the top coat. Can anyone with experience with BLO weigh-in with an opinion? As an alternative, my friend suggests Minwax Wood Finish ("Penetrates, Stains, & Seals") which he believes will cure adequately in a day or two for top-coating. Any thoughts?

Preston Earle
www.SawdustForBrains.blogspot.com
 
Preston,

At a seminar by Bob Flexner he said that BLO will dry in a few days but it takes forever to cure.  I think the Minwax product is a much better choice.

Dennis Bork
 
I have used BLO under shellac for a long time on many projects. If you cut the oil 1/2 with either mineral spirits or turpentine, put it on, wipe it off, you can immediately pad on the shellac with out waiting for the oil to dry. The oil will act as a lubricant and dry and cure under the shellac with out a problem. I have done this for years, the only disadvantage I have seen is that the texture or pattern of the wood grain will telegraph through the finish slightly as the finish cures so if you want a high gloss finish you need to come back latter to get the high gloss. In the current issue of Fine Wood Working's finishing wood Jeff Jewitt outlines this method in an article on page 50 called "Done in a Day". I would think you can do all your boxes start to finish in less than an hour apiece.
 
Hi Preston       It's been my experience that people that know about BLO don't use it on there projects they worked so hard to complete. History shows us a ton of uses, but it also shows as many reasons to use a different finish. BLO under finishes will keep shellac or lacquer from penetrating the wood as well as it should.If the BLO isn't dry, the finish will lay on top and create addhesion problems.Not to mention fisheye if you use lacquer. And if that doesn't discourage you, BLO will turn black as it ages. Stick to shellac or lacquer, or both, shellac will work as a great sealer for most finishes.At least you will know when they are dry.         Randy
 
At the seminar, Bob Flexner showed us a simple experiment.  Place a small puddle of BLO and a varnish on a glass plate.  After a week or two pierce the surface of each with your finger nail.  The varnish will probably be hard all the way through but the BLO will not.  He said to try it again in a month or two and the BLO will still be soft.  And yes it will blacken with time.

I have to admit I've never used it because of what he said.

Dennis Bork
Antiquity Period Designs, Ltd.
 
This issue of BLO turning black over time has come up before. The last time it did I spent a number of hours trying to find actual research that confirms this. I read most of what's on the WAG web site as well as the wood product lab site. I could find no research to support this claim. There is some hear say written, one example given is the existence of old wooden planes that have turned black, however most of these have been treated with unboiled oil or mutton tallow. In over 40 years of restoring antique furniture I have never seen BLO turn black under a finish. I have seen a number of Victorian walnut pieces that had turned black. In each of these pieces the solvent that removed the black gunk was alcohol which led me to believe it was a shellac related problem. In other cases where I've seen black build up on surfaces it has washed off with mineral spirits, BLO once polymerized will not wash off with alcohol or mineral spirits. At this point I plan to still use BLO as I always have. I welcome anybody that has real research to contribute, I am always ready to learn.
 
Preston - I use BLO frequently to finish projects.  So long as you wipe the excess off after about an hour after application, it will dry sufficiently to handle or over-coat in about 3 days at 65 degrees F.

As noted, trying to over-coat with laquer or polyurethane is asking for trouble, but shellac will stick with no issues.

If you want an alternative that contains oil but will dry faster and harder, you could consider Watco Danish Oil, or Behr's Tung Oil Finish, both of which are oil/varnish mixes.
 
I've used BLO on almost everything for over 30 years and have never seen it turn black on my stuff or old stuff. If left unsealed it will pick up dust over the years.As far as adhesion goes, I've watched a finisher from Italy do a shellac paddded finish over raw linseed oil and have it done in a day.-Al
 
Preston,
I too have used BLO on many projects for nearly 40 years.  As a finisher for the Kittinger furniture Co. where we made Williamsburg reproductions and Newport reproductions we used a mixture of BLO and lacquer thinner. I continued to use this mixture professionally ever since and have never had a problem.  I have used it under both lacquer and shellac often applying in the AM and topcoating in the evening. This has been used onhundreds and more probably in excess of a thousand projects. I use a mixture of about 1/3 BLO to 2/3 LT.
When it comes to shellac think of French polish and for the turners out here you will recognize that friction polish is a mixture of aproximately 1/3 shellac, 1/3 alcohol, and 1/3 BLO.  I realize that every individual has their own version of this and the exact measurements will be mixed much like your mother's mixtures in the kitchen.  Often times the realityof the usage doesn't jibe with the lab but my 40 years and Kittinger's 70 or so years is good enough for me.
Ross
 
I too can vouch for the efficacy of BLO as a finish (or part thereof) on antique furniture. In almost 35 years restoring high-end seventeenth and eighteenth-century antiques, I too have seen black colouration wash off oiled furniture with solvents. Some of it was merely smoke ingrained into copious applications of beeswax.
 
Jack et al- This is a great example of theory versus practice. I've done things over the years that I'm sure were'nt supposed to work, but did, like veneering just one side of a draw front, for example.
Just yesterday I was speaking with a friend with lots of experience who told me that he'd just varnished a wood ceiling he'd put up. He didn't have enough of any one can of varnish, so instead mixed leftovers of three or four different brands all together, some poly, some alkyd, etc. It worked fine, even though some of them were not supposed to be compatible.
That's the great thing about these forums- we all get to benefit from others' experiments....Al
 
Jack Plane,

I like your web site, Pegs and 'Tails, especially the construction of the W&M chest.

Dennis Bork
 
Preston,

Try using a small amount of Japan dryer with the BLO to help it "dry" faster. I've used a mixture of BLO, Japan dryer and mineral spirits or turpentine under shellac for many years. More recently I've started to depend more on Waterlox (wipe-on varnish) as an oil type finish that will dry quickly allowing several coats in just a few days.

Because BLO nevers fully polymerizes, it will continue to oxidize the natural chemicals in the wood thus over time making it look darker (sometimes black). The dirt, dust, and oils that accumulate are a factor of the environment and lack of proper maintenance of the finished surfaces over time also contribute to the darker color. 

Happy Hoildays

Mickey
 
Hi All        To tell the truth , I don't know why I'm going to attempted this again, but here goes.  I know I won't change the thinking of the [ old guys] but lets think this out.      First I should admit I don't consider myself a period furniture builder but I do build on occasion. As a conservator of wooden artifacts my job is to maintain/repair high end collections for museums and private collectors.Credentials upon request.    Back to the story.  Preston's task is /was to finish his project in 5-6 days. BLO has a dry time of 36+ hours. Some of you at this point will wipe off the excess in an attempt to speed up the wait time. But, because as Mickey said, BLO never fully polymerizes, using it as a sealer will plug the pores and keep the finish from penetrating as well as it should.  Will it work??? Sure, but it will shorten the life of the finish.In short , you are putting a soft material under your finish coat. Other problems, no UV protection, it is great mildew food, is hard to remove, rags spontaneously combust, and turns black over time. Not to mention the chemicals, arsenic,beryllium,chromium,cadmium,nickel, all known cancer causers.The main reason it was used through out history is that it was cheap, not that it was good as a finish.Great for dipping fence posts, sealing sash , siding or as a binder in paint.In short, almost all modern finishes are superior in performances. And I can't think of any finishes that recommend BLO as a sealer.    This reminds me of the story of why barns where painted red, because the paint is cheap.Why was red paint cheap??? Because they painted barns with it.  And finely,the only reason I have ever heard for using BLO is that it makes the grain pop.??????    Something to think about...Randy
 
I have heard both sides of this discussion before. In another thread I asked if any one besides myself had  made a side by side comparison of shellac with BLO under it and without. I wanted to know if BLO really made the finish "pop". My samples don't show any difference, so why add another step? Just finish with your favorite color of shellac. If you have made a side by side comparison, same wood, same preparation, I would like to know what you have found.
The barn paints were cheap because red lead and white lead were cheap pigments, they were in use a long time. I don't plan to continue the practice for traditions sake.
Mike
 
Yeah, I have been following the W&M chest construction as well, very impressive.

On the BLO thing, i dont wanna get into the plus/minus of using it as a finish but one thing i will say is, period finishes were very primitive compared to today and those "crusty old finish" that some dealers/ collectors covet is mostly dirt/soot that has embedded and become part of the finish.
 
Mike,
After reading your comments the last time this came up I did a number of test boards. In most cases I found you are absolutely correct there was no apparent difference with or with out oil. I did find two exceptions, when using darker shellacs like garnet or seed lac on softer woods like pine a coat of oil helps keep the grain from reversing. Second when padding over alcohol or water based dye a coat of oil helps keep the pad from dragging the dye. I also think you get a faster build when padding or polishing over oil. Old habits die hard and I would miss the smell.

Jack,
I too find your site great. I check every day with anticipation waiting for more.
 
Millcreek,
I am glad to hear that some makes samples and tests these methods to see what actually works. I think the smell of BLO is one of the reasons many people use it, some just like the smell, for others it brings them in touch with an old memory. Those are viable reasons for using anything, it is the unreasoned approach, the "I don't know why, that is just how we have always done it", that I don't understand.
Mike
 
In decades of using BLO (Tried and True is good stuff) I have never, NEVER, had it do anything to change color over time.  In my judgement, this is an absolute  canard.  I challenge any person to show me something that has turned black or yellow by the application of such, as made by their own hand.
I work in mahogany only, if I can help it, and always start with a coat of oil, well dried, long before I begin the finishing process.  This allows me to see everything clearly, before finishing begins, and to find all those little scratches, etc that you just can't see in the unoiled version.  Some folks use mineral spirits or other evaporative mixes, but these don't show me what I want to see.  The BLO allows me to fix all such minor defects by sanding or scraping.  A simple wipe of oil afterward fixes the dry spots produced by such repairs.  I agree completely, having tried it a number of times, that oil will not produce any perceptible effect in color or other characteristics under a well polished shellac finish.  I leave as much fine sanding dust on the wood as I can with the idea that this dust will begin the pore filling process when mixed with oil.  I've heard some folks say not to do this because the grit particles get in there too and can even glint, but I've never been able to observe this phenomenon at 400 grit.
I recognize the origin of this particular thread was more about drying time than my above remarks.  Go back to what A. Breed said..... oil under French polish, applied in a day and I would add that it will dry hard in three days.  Read George Frank's book chapter on French polishing.
I believe other wierd things too, like oil is simply good for bare wood somehow.  I also believe that the care, effort and dare I say love a man puts into something he has constructed is somehow perceived in an unconscious way by all who see it.  I rub a lot of myself into each piece.  They simply "feel" different.  I believe houses can pick up and carry the negative energies of those who built them or have occupied them.
JD
 
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