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blue stain prevention in pine

oldhand's picture

Due to an horriffic ice storm in january I have a couple thousand bd.ft. of nice shortleaf pine to dry here in NC Arkansas. My local kiln operator is no longer working so it'll be air dried to start. I've always had trouble air drying in the spring without terrible blue staining problems even with careful prompt stacking and the usual precautions. Former kiln operator said there was once a compound marketed just to address the problem but couldn't recall any details. Anyone know of a product that will prevent blue staining in air drying? Thanks in advance.


oldusty's picture

(post #114257, reply #1 of 27)


      Are you saying the Blue is not present when the log is sawn ?

   But the Blue happens after cutting and while drying ?

    I was under the impression the Blue stain was a mold / spalting / fungus that occurred when the log was down for a while before cutting .

        curious     to know        dusty

mapleman's picture

(post #114257, reply #2 of 27)

My experience mimics Dusty's - the blue stain (at least in longleaf southern yellow pine) comes from the log laying on the ground for a while before being cut at the sawmill. If you have freshly downed trees I don't think you should have problems - but I'm no expert (there would be a gavel behind my name if I was ;-)

Make sure to get all of the bark off.




oldhand's picture

(post #114257, reply #3 of 27)

Nope the blue is not in the logs yet, it will be if they are not sawn promptly. But pretty, bright and green boards will do it real fast in this climate, likely even if very well stacked and stickered. Fungal spores come in on bugs and are sticky and hardly bothered by breeze. Spring is the worst time, it is little bother in winter. The fungus won't prosper below 35F but it takes 160F kiln heat to kill it. Not only do I find the blue unappealing I've yet to find a customer that wanted it. This happens in shortleaf and loblolly that I have experience with, can't say about longleaf.


Barrie2777's picture

(post #114257, reply #22 of 27)

I have been buying pine logs for over twenty years and that blue stain will form for sure in the log if it down a while before sawing. It will also form in the boards after sawing but it ALWAYS forms in the sap wood where the sugar is. I never buy logs sawn in the spring to fall, always sawn during the winter and stacked outside with a cover to prevent rain seepage. Since you are sawing now without choice I would sticker them on the breeziest and hottest knoll in the area. Make sure the top is covered from the sun and rain. The quicker it dries the better the results. It sounds drastic but you will be happy with your wood when it is dry in about four months.

oldhand's picture

(post #114257, reply #23 of 27)

Update ......... this is still an ongoing project, the sawing is going in spurts. That's out of my control.The pine sawn in rainy May went to blueville in a few days, stickered and stacked. I gave up on the chemical approach after some consideration. This month I started drying with the clothesline method [vertical cross stacking across a horizontal support] and have gotten promising results. Much of the clothesline stacked pine is well below 20% mc in the outer parts of a 1" board and shows little to no blue. Knock on wood, there's still a couple thousand feet to go and the threat of staining in the log increases with time. The science on blue stain is obviously complex to say the least. Voodoo perhaps to some extent.


Shoemaker1's picture

(post #114257, reply #24 of 27)

My 2 cents Canadian.
In British Columbia and Alberta Canada, the Mountian Pine Beetle is killing massive amounts of pine and now starting on other species.
The beetle is killed by cold winters of which we have not had. These trees turn red when they die. The mills have a year or two to get it processed, before they suffer from windfall.

These boards have a blue hue to them as a result of the pine beetle kill. The wood is sound and now some folks are marketing as "Denim Pine" I've see some nice furniture made from it.

I see a lot of this blue stain in 2x stock at the lumberyards.

This nastey little bug is making it's way east and predicted to be in Saskatchewan next year or two. It has devestated millions of trees and caused major cash damage also.

It is predicted that in 4-5 years that all the windfall wood will cause some unprecidented forest fires, that are hard to fight. but might be a blessing in the long term.

I am spalling a nice hunk of maple I got from a tree service. about two feet long 16 inches wide with a couple burls in it. hope to open it up in the fall and see what turns out.

One last observation. I had a nice big Manitoba Maple get blown down it had all sorts of red staining, closer to the base. I had to remove an Elm this spring due to Dutch Elm disease. It to had a lot of red stain, and it seemed to be associated with injury sites.

oldhand's picture

(post #114257, reply #25 of 27)

That is an interesting regional take but this is a somewhat different problem. Here in the south US healthy pines will develop the fungal stain on fresh sawn green boards in warm weather pretty fast. Weyerhauser sized operations deal with it effectively with large scale methods, it's a problem for smaller users. The stain doesn't affect the structural properties but to me is ugly. I hear about consumers who like the denim look but they haven't found me. And hereabouts a standing dead pine is often bug riddled in 6 months, basically ruined for human use. Insect infestations do occur in thick pine stands here but it seems normal enough over time compared to the sad wide spread havoc you describe. We will have a horrific fire potential across much of the state of AR for some years just from the ice storm damage that instigated this post.Not the least of the reason I've tried to salvage these trees.


oldhand's picture

(post #114257, reply #4 of 27)

The fungus takes longer to infect a log than a board, otherwise the process is about the same.


oldusty's picture

(post #114257, reply #5 of 27)


      The species I speak of are Western species Sugar Pine and Ponderosa Pine .

       So what you are experiencing is very different then my own so not sure whats up with that .

         I have used Eastern White Pine but am really unfamiliar with the species you speak of perhaps for those very reasons .

        We used to buy 2,000 lf units of 1 X 6" T & G that was called Blue Wormy Pine for little to  nothing . The holes are caused  by Beetles not really worms .

    These species tend to Blue in the log state when down .

          dusty , from Cherry


oldhand's picture

(post #114257, reply #6 of 27)

I can't say if it is the species or the region that makes the difference, no doubt it's known to science. But I do know here in the humid south it is a problem. Occasionally I see blue stain in SPF framing lumber I assumed was from salvaged logs. It is possible to dry SYP without blue, the big boys do it year round, but it's a struggle for me.


SgianDubh's picture

(post #114257, reply #7 of 27)

Here's some general information on sap staining fungi that may be relevant to this discussion. Slainte.


Microscopic sap staining fungi generally turn light coloured timbers blue or grey, and sometimes other colours such as yellow or red, thus making them less aesthetically attractive to a buyer. This group of fungi prefers gymnosperms, that is, coniferous trees, but they also attack hardwoods. Depending on the end use of the wood the discolouration sometimes results in lower earnings for the seller; the colour is immaterial when used for hidden structural parts in, for example, houses, but it’s less acceptable in visual structures such as fence rails.


Sap stained ‘Redwood’ showing blue, grey and yellow discolouration.

Sap staining fungi do little physical damage and make little difference to the stress grading of wood used for structural purposes, eg, buildings. The typical grey or blue staining is a consequence of the dark hyphae of the invading fungus or fungi. The discolouration mostly restricts itself to the sapwood, but sometimes the hyphae will spread someway radially into a log or board following the sugars stored in the wood’s parenchyma. The sap staining fungi don’t have the chemical armoury to break down the cellulose and other wood structures. They are therefore limited to existing off the sugars readily available in the sapwood and a plant’s food stores. As with all fungi a lack of water, high heat and low temperatures limit their activities. From a practical woodworking point of view keeping wood dry prevents sapstaining in stored wood; specifically keeping the wood below 20% MC prevents growth. There are many sapstaining fungi, including species within both the Ceratostomella and Diplodia genus, and fungi such as Ophiostoma piceae, Ophiostoma ainoae and Ceratocystis allantospora.

On a side note the Fusarium reticulatum fungus has for a number of years quite commonly been cited as a possible cause of red sap staining in the boxelder, Acer negundo. A more recent research paper casts doubt on this and discusses the introduction of fungi into wounds in the tree—in life the wounds could be caused by anything ranging from insects to major trauma, eg, damage by vehicles. In the study the researchers conclude that further research is required to pin down the actual cause of the red staining. They discuss the possibility that, amongst other fungi, Fusariam solani may play a contributory role in “a non-specific host response” (Morse and Blanchette, 2002, p 8). In other words the tree itself, in an effort to contain or reduce the infection, may produce the red sapwood staining that extends from wounds infected by fungi. Woodworkers seek out red stained boxelder for its decorative but fugitive colour which often shows to decorative effect in turnery and carving.

A lightly red stained turned box elder example. The staining is sometimes very extensive and vibrant red. (Photo courtesy of Randy Gazda.)


Morse, A and Blanchette, R. (2002) Etiology of Red Stain in Boxelder, Plant Management Network International. [Online] Available at: < >[Accessed February 23, 2008]

Edited 4/23/2009 3:01 pm by SgianDubh

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Ron01960's picture

(post #114257, reply #8 of 27)

You may want to ask this question of sawyers, there very helpful and there's a great deal of info available.
Please post a reply when you have it.

good luck with your search

Ron in Peabody

Dr_Spalting's picture

(post #114257, reply #16 of 27)

Just thought I would point out that the information copied in the above post is actually inaccurate. <i>Fusarium</i> does not cause the pink staining in boxelder, the tree itself produces the color in response to wounding.

More on the topic, the best way to keep the bluestain down is to get the lumber dry ASAP. Bluestain spores are often carried by various insects, and can get on your wood without ground contact. Luckily, bluestain doesn't usually progress very deeply into the wood, so if you catch it early enough you should be able to plane a lot of the blue out.

SgianDubh's picture

(post #114257, reply #17 of 27)

Dr Spalting, the text you refer to was modified from one of my own manuscripts. The original of my text does go on to say that  other causes are more likely. I confess I should have done a better job of modifying and shortening my text for use in this forum.

The primary research paper I used to create my original text in that little paragraph concludes that further research is required to pin down the actual cause of the red staining. There is discussion in that paper of tree wounds and the likelihood that Fusariam solani plays a contributory role in "a non-specific host response" (Morse and Blanchette, 2002, p 8).

If you have more specific information that would help me clarify the Fungi and Wood section in my growing  manuscript on timber technology I would very much like to hear more from you. Slainte.


Morse, A and Blanchette, R. (2002) Etiology of Red Stain in Boxelder, Plant Management Network International. [Online] Available at: < >[Accessed February 23, 2008]

Edited 4/23/2009 9:18 am by SgianDubh

Dr_Spalting's picture

(post #114257, reply #18 of 27)

Hello Slainte! The article you cited below was actually the same I was thinking of when I posted my response. I was thrilled to read the article when it first came out, as there had been a lot of 'shop talk' about boxelder red stain for years, but never any really solid research.

My understanding from the article was that, while the Fusarium occured in some red stained areas, it was not ubiquitous, and therefore the authors concluded that the red stain was produced as a host response:

"The stain’s ubiquitous presence in all wounded tissue and the inability of F. solani isolates obtained from boxelder to stain boxelder red in wood block studies indicates that red stain is most likely produced by the tree as a nonspecific host response to wounding" (Morse and Blanchette 2002).

If you have further research in this area, I would love to compare notes with you. I research spalting at Michigan Technological University, and am always looking to compare spalting research with others (although it seems no one else is really bothering with it).

I actually just wrote a blog post about the difference between host-response color and spalting in the Woodworking Life blog, here on the FWW website. You might want to check it out, as I do a short comparison on spalting pink stain and boxelder red stain.

Seri (aka Dr. Spalting)

SgianDubh's picture

(post #114257, reply #19 of 27)

Seri, I don't have additional research to help you I'm afraid. I am not a mycologist nor involved in research in your field. I am a furniture designer and maker that has an interest in timber technology.

I also write on woodworking subjects, and I am working on a book on timber technology from the angle of a woodworker's point of view for other woodworkers. I'm not writing it from a timber technologist's or scientists perspective. My text includes a bunch of stuff including discussion of historical, political, environmental and social issues surrounding trees and wood, etc, as well as nitty-gritty subjects like felling, seasoning, atmospheric humidity, fungi and wood, et cetera.

However, there is an academic element to my text for it does include Harvard Referencing, but not so much that the text becomes inaccessible to the general reader. I have done a lot of research in a lot of wood and tree subjects and my bibliography is huge.

Anyway, I haven't yet had chance to read your blog, but I will do so later. Secondly, I decided to edit the post you originally responded to and replaced the last paragraph on boxelder staining with the full text from my manuscript-- this is more wordy, but tells the story more accurately as far as I can tell. Slainte.

PS. Slainte incidentally is just a word that means cheers in Galic, not a name.

africanchippy's picture

(post #114257, reply #9 of 27)

I've had the same problem here in South Africa. A chemical is available but it is expensive and off course I wouldn't know where to get it in the US ! I've had good results by laying freshly sawn boards open in the sun for a few days, turning every day, before stacking. The idea is to surface dry the boards as quick as possible. You can also try spraying the boards with swimming pool chlorine ! I've used the granular stuff, mixed with water. Spray the boards, still let them "cure" in the sun before stacking. Only have the problem in the summer when humidity and temperature is high enough for formation of blue stain and/or mould. Good luck !

oldhand's picture

(post #114257, reply #10 of 27)

Thanks to all for the interest and info. I have been informed of chemicals formulated to combat blue stain but they don't look too practical on the small scale and that's without studying the MDMS[or whatever the hazard info is called]. Still looking at that though. If anyone wants I will post the trade names. The low tech approach seems to boil down to basic air drying practices and hope for dry, clear, cool weather. I just hauled the last of 170 logs to the mill and what they had already sawn showed no signs of the dreadful blue, yet.


KeithNewton's picture

(post #114257, reply #11 of 27)

I'll bet you already know that using wet stickers will make it a lot worse than dry ones,

I was up in the hills a couple of weekends ago, and it sure made me sad to see the damage that the forest got up there. Seems nothing escaped getting some damage.

One thing to keep in mind, is that if you get a batch with a lot of stain, that you could still get it pressure treated pretty cheap. It would be just as good, and probably wouldn't show up after the weathering started, but I am not sure about marketability.

DAC747's picture

(post #114257, reply #12 of 27)

As a former Timber Framer we used to use a lot of White Pine which blue stains in a couple weeks [or less] after cutting into timbers if it is not cared for. I believe we used to treat it with borax [mop and a bucket] and then get it inside our building and get fans blowing on the stacks of timbers. The air blowing was the best defense against blue stain. Also switch ends often with the fan.

oldusty's picture

(post #114257, reply #13 of 27)

   I toured a Columbia plywood mill in Klamath falls Oregon and they sprayed a bleach solution on all the Red Oak sheets towards the end of the line .

    Where the Oak makes contact with certain Iron or steel parts you get a stain from the tannin .

        Maybe there is more to this

                        regards      dusty

oldhand's picture

(post #114257, reply #15 of 27)

My research turned up chemicals sold to specificly to prevent iron stain as well. I never got to the details on what it was, cost and etc.


oldhand's picture

(post #114257, reply #14 of 27)

The fan trick was also recommended by the retired kiln operator. If the good stuff makes a small enough pile I may try it.


dkellernc's picture

(post #114257, reply #20 of 27)

A comment about the blue-stain fungus - it does indeed infect eastern white pine, as I can personally attest.  And in the boards that I have (it's a flitch-sawn stack from a huge EWP tree), the blue staining goes clear through the board, but it's only in the "sapwood" - the pink heart shows no discoloration.

I've been told by sawyer friends of mine that the only really certain way to prevent this after the boards have been sawn is to saw them in the right conditions - either in cold (winter) weather, or in dry weather in the fall and very early spring.

That said, I've a suggestion.  Bayer sells a product in the home centers called "Disease Control for Roses, Flowers and Shrubs" and it is a very effective general specificity fungicide.  It will kill a number of species of molds and fungi on contact, and it is also a "systemic" funcicide that's absorbed through the leaves of plants.

My thought is that you could spray down your freshly sawn boards right after they come off the bandsaw mill, and that would probably give you a couple of days to get the surface moisture to flash off.

Generally, fungicides aren't nice chemicals, but the homeowner's stuff for sale to the general public is the safest ones.  Another one that is a bit less effective than the Bayer material but is absolutely safe is Daconil (there are various brand names for this - check the label).  Daconil is approved for use on garden vegetables - there are very few fungicides that are.  One of the reasons for this is that Daconil is a suspension - it is not water soluble.

Once you've gotten the boards air-dried, you can simply run them through a planer to remove all traces of the fungal treatment - it certainly should be no worse than the older pressure-treatment chemicals (which was copper-chromium-arsenate).

oldhand's picture

(post #114257, reply #21 of 27)

That sounds like something worth a try. I'll give some thought to experimenting on this with the homeowner fungicide and the swimming pool bleach. If anything comes of this that vaguely resembles science I will report back. Meantime I'm still open to ideas. Thanks.


oldhand's picture

(post #114257, reply #27 of 27)

That was a good read, thanks.