sticker stain..

[Rob in NC]

im assuming this has been discussed at length but i did a search and couldnt find exactly what i was looking for. 

ive got some projects coming up that i want to cut some rough lumber for and use it in rough form but i know its going to have sticker stain on it after drying and i dont like the way it looks.. from what i can tell its not the sticker bleeding into the wood its the sticker shadowing the wood from the natural aging due to exposure from sunlight and that i dont know how you could ever avoid if your going to sticker it to dry. 

(i sticker under pole barns to dry - FYI - nothings in the weather directly but there is some light fading and pine gets that "honey" color after a couple weeks) 

[Sawmill Man]

It helps a lot if you use dry stickers to start with and then keep out of direct sunlight

[doc henderson]

rob, not sure of the volume you are working with, but you could intermittently shift the stickers a bit to minimize the one spot, vs share it with the remaining surface.  what type of wood.  even though rough will it be stained or finished?.  the sticker area may "catch up" over time and or the stain may blend it as well if used.

[K-Guy]

It could be that you are getting discoloration from being cut and in the air even if they aren't in direct sunlight. Are the stickers the same species of wood? 

[Don P]

It depends on what we are talking about. I distinguish between sticker shadow and sticker stain. Shadow is lighter than the surrounding wood and is caused by protection from air and light. That will often catch up pretty quickly after being exposed. Stain is from drying too slow under the sticker and is darker than the surrounding wood, enzyme or mold. That will show forever unless the rest of the wood weathers heavily.

When we built milled log homes the logs were milled per job, wrapped and shipped so were fresh, bright and had never seen the sun. I would set up story poles and angled braces on the deck to keep us plumb and on dimension as we cut and stacked for a week or two. When I would take them down there was an obvious lighter shadow from them. Sometimes the client would alert me that we had a problem. I'd say "watch that for a couple of weeks". It would usually take another week or two to get the roof on and by that time the shadow would catch up and disappear.

[GeneWengert-WoodDoc]

Light penetrates wood a few 1/100 of an inch.  Sticker stain is often much deeper.

Sticker stain is caused by differences in the speed of drying.  Generally faster drying is lighter color.  Because the wood under a sticker dries more slowly, especially when the sticker is wet initially or gets wet from rain during drying, the wood under the sticker is drying more slowly and so is darker.  So, dry stickers cause the wood under them to dry about the same rate as the wood between the stickers.  This is why grooved stickers work well...the wood under them dries faster than a solid sticker.

[moodnacreek]

Very rough sawn stickers, 3/4" wide work well if you don't have grooved ones. I like spruce or hemlock. Tried 1/2" but the layers will shift and collapse.  Pine on sticks during rainy summers stripe badly. This is the reason for 'rougher head' commercial rough cut lumber.

[Rob in NC]

Light penetrates wood a few 1/100 of an inch.  Sticker stain is often much deeper.

Sticker stain is caused by differences in the speed of drying.  Generally faster drying is lighter color.  Because the wood under a sticker dries more slowly, especially when the sticker is wet initially or gets wet from rain during drying, the wood under the sticker is drying more slowly and so is darker.  So, dry stickers cause the wood under them to dry about the same rate as the wood between the stickers.  This is why grooved stickers work well...the wood under them dries faster than a solid sticker.

This makes sense - although the wood is stored dry im sure the area below the sticker cant breathe and therefore drys at a different rate. My stickers vary but most of them are a big lot of 50+ year old tobacco sticks (oak) that are dry and stay stored dry when not in use. 
The lumber i want to use will be used inside so i dont know if the light/dark sticker lines will catch up when finished on the wall or not. Im planning to do the interior of my pole barn walls - it would not be sealed or stained. 

[Rob in NC]

It depends on what we are talking about. I distinguish between sticker shadow and sticker stain. Shadow is lighter than the surrounding wood and is caused by protection from air and light. That will often catch up pretty quickly after being exposed. Stain is from drying too slow under the sticker and is darker than the surrounding wood, enzyme or mold. That will show forever unless the rest of the wood weathers heavily.

When we built milled log homes the logs were milled per job, wrapped and shipped so were fresh, bright and had never seen the sun. I would set up story poles and angled braces on the deck to keep us plumb and on dimension as we cut and stacked for a week or two. When I would take them down there was an obvious lighter shadow from them. Sometimes the client would alert me that we had a problem. I'd say "watch that for a couple of weeks". It would usually take another week or two to get the roof on and by that time the shadow would catch up and disappear.

90 % of my sticker variation is lighter - not darker so this gives me hope that once on the wall they will equal out. Im assuming on the interior it will just take longer. 

[GeneWengert-WoodDoc]

Sticker shadow and sticker stain are the same within the industry.  Usually the seller calls it sticker shadow and the buyer calls it sticker stain.

[Rob in NC]

Here is another problem i run into here. im starting to assume in the southeastern US you wont use rough cut lumber without mold or sticker stain on it. This i cut same day i dropped the tree - beautiful clean white fresh sawn pine - each board i scraped free of sawdust and stickered on dry stickers - put under my pole barn and 4-6 days later this is what it looked like. Its unusable as rough sawn now for interior paneling. Now i can run it through the planer and it be fine but thats not the look i wanted in my shop i like the rough surface the sawmill leaves behind. This stuff is really frustrating to me - spend 6 hours cutting, scraping, stacking and have to re-plane all of it now to be usable. When you work alone everything is a time consuming task. Is there some magic formula im missing on keeping lumber looking clean off the mill to final application?

[doc henderson]

faster drying could mean thicker (taller, bigger gap) stickers and more narrow stacks with fans.  looks like maybe mold on the surface.  hard to tell from the pic.

[YellowHammer]

The secret to not having mold is lots of airflow, well into the 650 feet per minute range evenly distributed along the entire stack.  I use two barrel fans to cover an 8 foot stack, 4 foot high.  The airflow removes moisture and also cools the wood, both or which reduce stain, and will dry the wood in a matter of days.  When it is working, there will be as much as a 20° temperature drop of the airflow through the stack.  It's basically a swamp cooler and the wood is the wick.

At this point, with that stack, I'd load up a sprayer of bleach and water and spray a couple boards down.  Many times, the mold is reduced at least 90%.

Also, if you use diagonally fluted stickers, they help tremendously.  We use them exclusively on sticker stain prone wood.  

BTW, we have a lot of these fans.  



 

[Rob in NC]

can you post a picture of a diagonally fluted sticker?

[WV Sawmiller]

Robert,

   I was going to ask how you remove sawdust off your lumber but when I saw those wind tunnels I can see why you won't have any problems with sawdust. :D You can add one more fan and blow that stack all the say to Brookhaven Mississippi if you're not careful. ;D

[doc henderson]

we can only use up to 3 in Ks or we could start a tornado!   :D 8)

[YellowHammer]

These big fans are great.  They will dry a load of wood out fast in the summer, as fast as a kiln down to 15%.  They are a very efficient way to increase throughout.  

Sawdust isn't a problem, as long as you don't get down wind of the fans.  

He is where I buy my spiral stickers.  
https://kilnsticks.com/

[WDH]

I have gone to smaller direct drive fans.  The belted big barrel fans have been presented maintenance problems with bearings and belts.  Probably because I bought the cheap $300 ones.  Robert, have you had any issues with your big barrel fans?

[petefrom bearswamp]

As is well documented, Sugar maple is very prone to sticker stain.
I have sawed quite a bit of it and dried it without the stain issue.
When I sawed several hundred feet, I would stack and sticker with my home made grooved stickers that resemble an I beam in cross section.
After about a week I would re stack moving the stickers.
Of course I only sawed small volumes of this.
One or two logs I would stand the boards up along the sides of my pole building for a short period of time then stack.
No power at my mill and storage site so no fans.

[WDH]

Rob, your wood was also placed right next to a building which really inhibits air flow. 

[YellowHammer]

Actually, these fans require surprisingly little maintenance and I hate to admit it, but due to my drying sheds being full, most times the fans are outside blowing in for many months at a time, and get a good deal of rain on them. Basically, they are out in the weather.  

I much prefer the orange Home Depot fans to the black Lowe's fans which squeak miserably when the belts get loose. 

I tighten the belts every couple years, at most, a 10 minute job.  I buy mine in the fall, and due to their big size, the stores will really drop their price to get them gone.  The last ones I bought in October were from Home Depot, they gave me the second fan for free, just to make room for other stuff.  

[customsawyer]

I got several big fans from Tractor Supply. None of them lasted more than a couple of months. They were made so flimsy that when they went, they went all the way. I have a couple from Home Depot that are a few years old and haven't touched them yet.