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Cherry Air Drying

Started by CEaston, September 08, 2019, 03:15:37 PM

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CEaston

First time posting here. I am newer to slabbing and wood working, I have found a passion in it so I am trying to take in as much as I can. I slabbed these Cherry pieces the other day and I have seen before that when stacking Cherry for drying, the wood will discolor where the spacers are. I am planning on air drying these in my garage by the way.

Why does Cherry do this? Will I be able sand these out? Is there a better way to dry Cherry that wont cause the marks from the spacers? 
 

I posted some photos from the slabbing session. I always enjoy the grain reveal once the top layer is cut off.

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doc henderson

cherry, like some other woods like mulberry and hedge, will darken over time.  Most of mine will plane out.  this is usually due to oxidation and sunlight prob. will speed this up.  keep the pile out of direct sunlight, and if the wood under the stickers has not darkened as much, then i think it will even out over time.  if the stickers are green and full of moisture, it may seep into the wood and require more planning to remove.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

CEaston

Quote from: doc henderson on September 08, 2019, 05:12:53 PM
cherry, like some other woods like mulberry and hedge, will darken over time.  Most of mine will plane out.  this is usually due to oxidation and sunlight prob. will speed this up.  keep the pile out of direct sunlight, and if the wood under the stickers has not darkened as much, then i think it will even out over time.  if the stickers are green and full of moisture, it may seep into the wood and require more planning to remove.
Thank you for the response and information!

Don P

That is called sticker stain, usually caused by using green stickers. You want dry stickers that will suck up the moisture from the board rather than keeping it damp under there. If it is high value stuff it doesn't hurt to resticker it after a week or so with fresh sticks in a different place, that way the stickers will be on a dry surface and the wood that was hidden under the first set of sticks gets to dry quicker.

A garage is not a great place to dry, half the weight of those slabs is water, in an enclosed room it is hard to get rid of that moisture fast enough. Its also not good for the contents in the garage or the room itself. If you gotta do it keep the doors open as much as possible and put a fan on it.

doc henderson

My ac has been broke in my shop.  just put a central in to replace the 2 window units.  instead of a drain, i have a 5 gallon bucket.  if it goes over 24 hours then the bucket is too full to carry without spilling.  so a month with no ac, and my stickered wood that i could put a fist behind a strap, has swollen up and now i am removing water from all those (boards) sponges.  this has been for about 10 days or 50 gallons of water or 400 pounds of water.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

JBailey

Sir,
nice looking cherry!  Like you, I'm air drying cherry and its a great wood once its dry. Stable, strong, responses great to tools and wow, it looks good.
One thing I would recommend is putting Anchorseal or something similar on the end grains.  That will greatly decrease checking - cherry isn't a bad checker, but it does check, especially with big slabs like you have. I can see the difference between cherry that had Anchorseal on ends and those pieces that didn't - and I wish I had sealed everything. Get it on ASAP before checks develop.  You want to protect that beautiful stuff.
Happy wood working and may you make lots of great projects with this cherry.

JBailey

also, I would add: make sure your stickers (spacers) are the same species as the drying wood.  So your cherry gets cherry spacers.  Using different woods can result in discoloration.


GeneWengert-WoodDoc

Check out this article about stains...go to the sticker stain section.

https://forestandwildlifeecology.triforce.cals.wisc.edu/wp-content/uploads/sites/111/2017/07/64.pdf

Anchorseal on the ends is a good idea, but it must be done before the ends begin to dry, as the coating only prevents new checks, but has little effect on controlling existing checks from getting worse.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

CEaston

Thank you guys for the responses and information. 

I know that I am not running the ideal setup for drying. I, unfortunately, do not have the best space for my craft. I guess you could say I am more of an "Urban Woodworker" using the space of my driveway and garage in my neighborhood as my working platform.

As far as the drying inside of the garage. What if I did something even as simple as throwing a tarp over the wood stack and then running a DH under the tarp. Would that be worth anything or just a waste of time?

I have not used Anchorseal yet. I tried a wood glue combo on the end grain for my last batch and it helped with checking but still not as much as I would like. I have a few Black Walnut logs on the next to mill schedule I will definitely try the Anchorseal on.

doc henderson

for that idea, might need a frame to hold the tarp up and out, fans to circulate and room for air movement so you do not burn up your dehumidifier.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

I've used 2" thick sheets of xps foam to build a box to put the wood and DH in, that's the blue or pink stuff, well or green, smooth not the white beadboard. Welding rod, coathanger metal or similar poked in to "nail" the box together and then duct tape and a couple of cans of great stuff canned foam to seal all the gaps. On the floor sheets I put osb on top of the foam to make a solid base. Stick a remote thermometer probe in there and drain the DH out into a pan so you can monitor drying rate. With it insulated the heat from the dh will build which helps to a point but keep an eye on that and keep it below the thermal overload on the dh. You can fancy that up with a thermostat. The problem with the tarp is you are trying to dry the entire space, or in most garages you are trying to dry the world.

CEaston

I like that idea with the XPS foam board. It would not eat up a whole lot of space in my garage and contain the drying environment. If I am going to go ahead and start to plan a design for this should I make an effort for an inlet port that I could pump in some hot air? Something as simply as a fan blowing hot air in that is pulling from a propane/ electric/ some heat source? I guess with that in mind maybe even an outlet port as well that could be where the DH is pulling from.

doc henderson

I think if there is room, you could put the DH inside the container.  the heat can be alight bulb, or halogen work light.  use caution in case there is a fire.  the foam can be set up in a way to take apart and reuse when needed.  I would drain the DH via hose to the outside of the container.  this way you can quantify the water removal.  quite satisfying.  @YellowHammer uses this as a sign that the wood is "done".  I think you want this simple as it will take weeks and you do not want a fire, especially in you attached garage.  any kind of forced air or return air will be more difficult as most heaters and DH are not designed for that.  may reduce the efficiency and or increase risk.  have fun!!! ;)
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

YellowHammer

As 
@doc henderson 
mentions, I believe the best way to accurately document the actual water removal, and to develop a feel for it, is using a container to capture the water removed.  I like to use a calibrated 5 gallon bucket.  This assumes there is no water removed through other means, such as vents, as moisture laden vapor. 

For example, with 1,000 bdft of red oak, if I get more than 5 gallons of water a day, then I am going too fast.  Less than 3 gallons, and I need to dial things up.

Drying wood with an electrical means, there is always the risk of fire.  Especially when dealing with the overly corrosive effects of wood moisture.  I have had quite a few mechanical devices break down inside the kiln due to corrosion, so please be very careful.  I would make sure you have a smoke detector in very close proximity.   
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

CEaston

That makes sense. I am thinking that I would not introduce any electric heat source with this first design and just keep it with the DH. 

As for the drying/ water amount per day to gauge if it is going too fast or too quick, is there a formula to follow for every x amount of board ft and for each type of wood.

For example is the water amount the same for 100 bf of cherry as it is for 100 bf black walnut? Is there a scale for water amount for different amounts of wood in kiln, 1000 bf of cherry should be 2 gallons a day and 500 bf of cherry should be 1 gallon a day. 

Any charts or articles I should read up on for this information?

Thank you guys for the information, this has relay helped me with putting together a better design for drying.

doc henderson

@GeneWengert-WoodDoc has data and more articles written than you can read.  if you know starting MC and species as well as bf, then gene can show us how to calcite the water loss by %.  some species like oak need to go slow so you can load more in, or raise the humidity or turn down the heat/cover part of a solar collector.  if you are drying maple and want to go fast, you are limited by the power of your kiln, solar or DH ect.  to figure starting MC it is prob. best to weigh and then oven dry a sample, calculate starting MC, then start from there.  then as you remove water and see the volume, convert to pounds, and can estimate daily losses.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

doc henderson

@CEaston in theory if you had a container and all you did is replicate the relative humidity inside your house by making it lets say 35%, then you might as well just put the wood in your house.  it is the heat that motivates the water to come out faster.  the lower RH is what creates a bigger internal/external gradient and can lead to defects.  so you need heat, air movement, and controlled humidity, not just low humidity per say.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

CEaston

@doc henderson so essentially, dont waste my time/ money unless I have some means of raising the temp.

What are the numbers I am as shooting for in a controlled environment?  ie 150 degrees f and 35% RH.

doc henderson

I am a hobby guy and there are others with much more knowledge and experience.  @YellowHammer uses a halogen work lite for heat.  I have used a simple temp and humidity monitor remote in the pile, by accurite for 14 dollars. The schedules are published and one of the researchers over the years is @GeneWengert-WoodDoc .  he should chime in and reference the schedules.  your goal might be temp of 115 with 85% humidity for wet off the saw and this is when many defects are set in stone.  if air drying first, then you are really talking about speed. the higher temps are usually at the end to kill bugs and such.  with 4 sheets of foam you could make a 4 x 4 x 8 (1cord sized) container.  if you leave room for a light some fans, and a dehumidifier there will be less room for wood, but then you have a real kiln.  I have great success with slabs just being in my cooled in the summer and heated in the winter shop, but takes a couple years.  slow for thick slabs might be the best.  this is why some like solar, low tech and low operating cost, and almost foolproof.  heat during the day, relaxing wood at night, vent out the humid air, cost is for fans to keep the surfaces dry.  I have also done a out door pile of wood wrapped in plastic with ventilation.  look at timbergreen simple solar cycle kiln.  hopefully others will chime in, but do not be discouraged.  starting out it's all about learning and making upgrades as you can depending on space, time, money ect.  Keep up the good work. ;)
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

doc henderson

in traditional kilns. the relative humidity is measured by having a dry bulb thermometer that just measures the temp in the kiln.  then another with a wick over the bulb of the thermometer that is kept wet.  just like sweating, the moisture that evaporates lowers the temp.  the dryer it is, the more it drops the temp on the wet bulb thermometer, called the wet bulb depression.  the moisture in the wood follows a gradient from wet to dry, and goes in both directions.  so dry wood in a wet surrounding takes on water and wet wood in a dry environment, gives up water.  too big of gradient from the core of the wood to the surface caused stress, and this is why we control the kiln.  if already air dried then it is harder to screw things up, and then it is about drying to target MC, in a shorter time.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

mredden

Quote from: doc henderson on September 19, 2019, 02:00:24 PM
...

  I have also done a out door pile of wood wrapped in plastic with ventilation.  look at timbergreen simple solar cycle kiln.  hopefully others will chime in, but do not be discouraged.  starting out it's all about learning and making upgrades as you can depending on space, time, money ect.  Keep up the good work. ;)
I have watched timbergreen's 2 videos, but I cannot ind it if he did a third which reveals the results.
I am considering using that method for drying five 12'x31"ish pecan slabs that have been air dried to about 16% at this point. If I do it, I'm going to wait a bit longer til it reaches our local EMC of about 13.5. I am a bit nervous about "experimenting" with these 5 boards, but I think I'm gonna go for it.
What's the worst that can happen?

doc henderson

spontaneous combustion!...  you asked and I made that up. :) :) :)  I have done elm slabs and got them to 9%, and had I been more diligent. could go lower.  the key is stacking in a place that gets some sun, and making sure the plastic does not rip or blow off, re-wetting the wood.  I did mine without anything under except concrete slab, and water in the am would run from under the plastic.  I put two box fans inside the slab stack ( I had a couple rows).  my problem was I uesd strapping and occasionally the metal would tear the plastic.  I should have put osb on the top to keep the sun off, after dry, I store it under a black tarp. if they currently air drying, just cover with plastic and see what happens.  throw in a remote sensor and follow high and low temp and humidity for fun.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

doc henderson

 

 

this is a stack of maple and elm boards and you can see the 2 inch thick by 22" by 10 feet elm on the pallet just behind (bottom left).  I have changed to poly strapping as the steel would rust and stain the wood, and as It shrinks, the poly buckles can be retensioned.  I now keep a black tarp over the stack, it will go into my storage container soon, with a home dehumidifier to keep it at home room humidity
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Don P

When you put a DH inside a sealed insulated box the temperature rises, that is your heat source, nothing else should be needed. That is the reason I said to stick a remote probe from an indoor/outdoor thermometer in there, you may need to trim the dh back.

doc henderson

Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

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