Ambrosia Maple

[YellowHammer]

Flatrock58, that's some nice maple. 

YH. what did you do to stop the sticker stain with your stickers? I'm now sawing red cedar for my stickers, but I just air now. Hope to build a solar kiln next year.

xlogger,
Airflow, airflow, airflow.  The air must be moving immediately after sawing.  Fans are a must if it is even close to hot and humid.   

WDH is 100% on the money.   

I have run some experiments and determined that the greatest chance of sticker stain in red maple occurs in the first couple hours after sawing and tapers off after a couple weeks.  Surface moisture and high temperatures on the boards greatly increases sticker stain potential and everything must be done to dry it immediately and keep it cool, even though the board itself still has moisture in it.  In addition to accelerated drying, lots of air blowing over the stack causes evaporative cooling and greatly reduces surface temperatures, especially in the warmer months.
So I do several things specific to ambrosia maple that I don't necessarily do with other species due to its tendency to deep stain to the point where it won't plane out and the wood is ruined.  Here's what I do:
1.  Big fans running on high for about two weeks, as soon as the wood is sawn. Butt the fans right up to the stacks and get the air moving over them.  I wont even saw red maple unless I have some fans ready and waiting.


2. "H" stickers to minimize surface contact with wood.
 
3.  I don't spray these boards with insecticide because it wets the boards under the stickers and I want their surfaces dry immediately.  I sterilize the wood later in the kiln.
4.  I spread the boards liberally out in the lumber stack, putting at least a half an inch between edges.  I want the air moving vertically in the stack as well as horizontally.  I don't want any dead spots.
5.  Every couple days, use a hammer to move a few sample stickers in the stack and see if any stain is forming under them.  If it starts to show, I beat all the stickers about an inch to the side to let the wood under them dry out.

If you go to all this trouble, it will be worth it as the boards will dry without any sticker stain at all, and will be bright with no gray or fade. I sell the ambrosia maple starting at $4 per bdft, so a kiln load represents a significant profit and discovering a load of sticker stain is the start of a very bad day.

Also, if these fans are used in this method with green oaks and other similar species, the boards will crack and be ruined.  The air velocity is too high and the wood will dry too fast. 
YH










   

[flatrock58]

Yellowhammer

Do you have to keep air flow on the maple even with cold temperatures?

thanks,
Steve

[YellowHammer]

Yellowhammer
Do you have to keep air flow on the maple even with cold temperatures?

I do, it's cheap insurance because even though the risk of sticker stain is greatly reduced in cold weather, I did stain some last winter with no fans running, so now I run them 24/7 and let the fans rapidly dry the wood to a point where it likely won't stain if I get a warm damp spell.  A fan's drying effectivness is proportional to the wetness of the wood, so the wetter the wood, the better the fan's high velocity airflow over the wood removes moisture.  That's why after a couple weeks I remove the fans or move them to a different stack because the wood is dry enough where the fans lose their effectiveness and the maple is out of the danger zone as fast as possible.
Normally, two barrel fans will cover 1200 Bdft of lumber, 600 Bdft on the suction side, 600 Bdft on the exhaust. 
YH

[xlogger]

I slab up a red maple log about 5-6 weeks ago into 2" slabs. I just put them under a shed with stickers no fan. I'll have to see how they turn out. I don't do much volume here, wonder if I do another maple and stood it up on edge under the shed how would that work?

[Seaman]

Thanks WDH and YH for the great tips !
XLOGGER, I stood up maple in my shop to dry, it cupped and bowed. Your mileage may vary.
Frank

[WDH]

My experience is that slabs have to be dried in a herd.  A single slab standing under a shed is totally exposed on all sides and can dry too fast for its thickness.  The thicker the slab, the worse the outcome.  I have found that it is best to sandwich the slab with stickers under two layers of boards, one on bottom and one on top of the slab, or I sticker a number of slabs together and then cover the top layer with stickers and another layer of other, non-slab, boards.  This helps keeps the drying under better control.  The moisture evaporating from the slabs keeps the neighbors from drying too fast. 

There is nothing fast about drying thick lumber using conventional processes.