Anti-stain treatment

[ohsoloco]

Okay, it's (finally!) getting to be the time of year where I have to worry about this.  Over the summer months, because of my work schedule, I will have to mill lumber on the weekend, and let it sit until friday when I can deliver it to the lumberyard to sell.  Last summer when I cut a stack of white oak, I stickered it for the week until I could deliver it to keep it from growing any mold or fungus-type stuff.  Problem is, I don't have a shaded area to stack it, and a lot of it developed surface checks.  What can I put on the lumber to prevent staining if I stack this stuff tight together?  I've seen cherry start to mold after one day of being stacked tight.  

I read somewhere about using 50/50 bleach and water....will this "bleach" the lumber?  When I was working as an apprentice at a timber framing company, they used this solution on the white pine timbers to make them light in color (and it worked really fast as well).  

Could I hear some suggestions (products, advice, etc.)?

[Jeff]

We use a mix of PQ8. We mix 1 quart to 40-50 gallons of water. It can be applied by spraying emersing or flooding. We use watering cans to saturate every layer of boards.

I found this source on the web. http://www.loghelp.com/ccorner/cc.html

[Minnesota_boy]

Why not create your own shade?  I like to put an extra row of stickers on the pile, then stack some slabs up there just to keep the sun off the top of the lumber stack.  If your checking goes more than one or two rows deep, make the stickers larger and longer to make the shade extend over the side of the pile.

[Don P]

I've looked up some info on blue stain, or sapstain, since the denim pine season is here.
Sap Stain is caused by a fungus. This fungus feeds on the sugar within the cell lumen (cavity). The sugar level in sapwood does not vary enough seasonally to discourage blue stain, there is always sufficient sugar to support it. Heartwood does not normally contain enough food to support it. The color is the pigmentation of the hyphae of the fungus.

There are four conditions necessary for the fungus to thrive:
(1) Temperature: Between 50 and 130*F, optimum is between 70 and 90*F
(2) Oxygen: the fungus requires oxygen to grow so sprinkling will prevent it, however once drying begins there is sufficient oxygen present within the cells to support growth, sprinkling then will do no good.
(3) Moisture: there is sufficient moisture present down to 22% although the greatest risk is above 40%
(4) Food: the sugar in the cells is always there, you can poison the food supply though. As a rule of thumb wood that can't be rapidly dried should be dipped within 2 days at temps above 70, within one day above 80*F.

This was from a drying class, I have a note that Timberline magazine has ads for NP1, Busan, and Sta-Brite as sprays or dips to prevent stain.

The official line is that blue is just a nuisance, I tend to think it is worse than the pro's let on when the wood is destined for exterior exposure. Below are links to some micrographs of bluestain used in a wood science course at NCSU.  If you look at how the fungus moves through the wood it runs through the rays kind of doing a roto-rooter job on them and then the hyphae punch holes through adjoining cell walls at will. It sure looks to me like a bunch of wicks set up to suck surface water rapidly into a piece of siding or whatever. Instead of surface water having to find a harder route to the interior, there is a system of breaches to the affected subsurface cells. Bluestained wood takes stain faster and deeper than normal wood, this is in my mind the "proof" of this rapid wicking.

This is a slide of bluestain moving through a ray cell
http://courses.ncsu.edu:8020/WPS202/fungi/decay.slides/img009.gif

Here it is pushing through a cell wall, just like a mouse, chew a hole through the wall right beside the door :D.The "donuts" are pit pairs connecting cells to each other and to ray cells.
http://courses.ncsu.edu:8020/WPS202/fungi/decay.slides/img011.gif

The course outline is here, and is very good.
http://courses.ncsu.edu/WPS202/syllabus.html

[ohsoloco]

Yesterday I received a letter in the mail from my lumber buyer that they sent out to all of the lumber suppliers.  It says they are reminding us to apply anti-stain solution to all non-maple lumber now that the weather is getting warm.  They are recommending a product called "Sta-Brite."

I wonder why they don't want it applied to hard or soft maple  ???

[Ron Wenrich]

We have one buyer that will not accept any type of spraying.  I'm not sure if it has anything to do with environmental hazards or if it discolors the wood enough that it is hard to match.

Other buyers are glad that we do spray.  I think we are using the "Sta-Brite" stuff.  Not sure.  We bought a drum of the stuff and sprayed all of our tulip poplar.  It will last us another year.  

If you can keep poplar dead piled with no stain, then its worth it.  Any stained wood will drop to 2 Com, although some won't even take it.  Others don't care due to the staining process.

We don't spray any of the oak or ash.  Spraying won't help your surface checking.

This is the time of year where surface checking is the worst.  Rapid air movement with relatively low humidity.  You want to limit the air flow.  White oak is the worst for surface checks.

We used to use a cover on top of our lumber.  Simply some thin lumber nailed to runners.  Then we would place it on top of the lumber stack.  Saves lumber by putting it under roof without the expense of a building.

[ohsoloco]

Last year I cut some white oak on a weekend, and couldn't deliver it until Friday, so I stickered it by the mill until I was ready to deliver it.   Talk about surface checking  :(   It wasn't isolated to the top layer...there was checked lumber all through the stack.  I hated to see some of those 12+" wide clear boards with checks on em  :'(   Looking back, I'm surprised I made as much money as I did with that stack.  Of course, I just stacked it under a tree and didn't cover it up, so it still got some sun.  

The lumber buyer also mentioned that it was a good idea with oak lumber to put a layer of low quality boards on top of the stack sort of like a sacrificial layer.

[beenthere]

My recollection is that white oak will start the checking process the instant the board is exposed to air. Just putting a board on top of the pile in the sun or even in the shade with a warm, dry breeze blowing over it will start that checking process (surface wood cells drying). Red oak is close to the same. Ideally, laying a tarp over each layer of boards when green stacking can keep a lot of surface checking from happening. A lot of work, but the value of oak lumber with surface checks isn't much compared to the value with 'no checks'.

As you mentioned, you stickered the white oak, but didn't drape the pile to keep sun and wind to a minimum and there was a lot of checking. Do you remember what the conditions were like those few hours before your white oak was stickered? Were they "exposed" naked in the sun and wind?  It might be a clue as to why the severe checking happened.

This type of checking happens when pallet mills decide they will pull clear oak boards out of their pallet production line, creating a dead pile that gets added to during the day. The top fresh boards lay exposed for just a few minutes or a half hour before being covered by the next "high grade" board, which is long enough to start surface checking. The end result is a pile of clear, but low quality white oak which has no more value than pallet lumber.

[ohsoloco]

When I was milling the white oak I would put it right on the pile and sticker it as I milled it.  It was really warm and sunny that day, which was why I stacked it under a tree, but it only shaded the stack for part of the afternoon....by 4 or 5 o'clock the sun was hitting it again.  

I would be afraid of staining if the pile was covered with a tarp...wouldn't this be a nice environment for mold/mildew?  

Do you think if I stickered the lumber for a week before delivering it that it would be dry enough to stack tight together without fear of staining?  I wasn't sure if this would dry it out enough to hinder staining until the lumber was graded  ???

[Bro. Noble]

We always sticker our oak right off the saw and cover the stacks with plywood. We pull the stickers just before we load it because our buyer doesn't want it delivered on stickers.  They grade it within a couple of days.  We don't have a problem with stain or checking.  

With walnut,  they don't want the lumber stickered at all.  The surface drying prevents it from steaming evenly.  We wait till cool weather in the fall to saw walnut.

Noble