# Warping after planing



## mgreen

This is only the second time I have tried purchasing rough cut lumber and trying to plane it down to required dimensions. I purchased about 150 BF of air-dried poplar. I do not own a moisture meter but according to mill, the wood has been air-drying for a few months. Once I milled a few pieces (not to final dimension) I noticed the boards beginning to warp and twist. I re-stacked and clamped them down but I am afraid the wood isn't dry enough and they will continue to move. I am not sure what to do at this point. I have a dehumidifier in my basement and it normally is around 50-60%. Any suggestions would be appreciated.


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## mdntrdr

Definitely not dry. Planing both faces equally will help reduce warp/twist. Buckle them down with stickers until they are dry. :smile:


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## mgreen

How long do I have to wait for the wood to stop moving after initial planing?


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## gideon

"air drying a few months"? if thats what they said then they're a crap mill.

it takes a year plus per inch to air dry. kiln drying is faster. could that be what they said?


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## mdntrdr

Depends on the surrounding conditions and how thick your lumber is.
A moisture meter is a very handy tool to have. 
Planing before dry is a waste, as you will have to joint/plane again after it reaches equilibrium. :smile:


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## Paarker

Jointing before planing is a must I only say this because you didn't mention if you jointed the wood first or not.


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## MidGAOutdoor

u really need a meter. harbor freight sells one for $12 its not an expensive one but it gives u an idea. it works for me


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## Ibangwood

Buying a moisture meter is like buying insurance. You pay for what you get. DO not buy one from harbor freight. You get false readings. I have a nice Wagner one and it's a scan type and it works awesome. Setting the meters for specific gravity helps a lot. Again you pay for what you get


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## walnutavenue

I've been shop drying for a little while; using a dehumidifier in a basement just like you. With relative humidity at 50% or below I got a stack of 1" elm boards dry in 9 months. They may have been dry sooner, but I didn't have a meter until then. That first stack had a tiny amount of staining where the stickers touched the lumber, so since then I've put a box fan against the stack that wired into the shop lights, so anytime I'm working it gets a little circulation, which has resolved the staining problem.


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## mgreen

So I picked up a moisture gage today. The wood is anywhere between 6 - 12%. Much better than I thought.


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## HowardAcheson

Remember, when planing rough sawn lumber, you should take an equal amount off both surfaces. Run the board through the planer, flip it over, adjust the planer and run it through again. Keep up the steps until the board is the thickness you want. Then stack and sticker the boards until you are ready to use them. Do not lay them on a flat surface that restricts air flow to both the top and bottom of the board.


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## cabinetman

You don't need a moisture meter to know if the lumber is dry. You need one to know the percent of moisture content. To know if the wood is dry, or dry as it will get for the ambient location, weigh the wood. When the wood stops getting lighter, it's as dry as it will get for where it's located.

To minimize the possibility of warping after planing would be to plane both sides taking off the same amount each time. When done and the thickness is what you want, stack up the boards and sticker them to maintain air circulation around them.

















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## Ibangwood

That's a very false statement. Just like working out you gain strength fast ,with wood it loses a lot fast in the beginning. Then It slows down a lot. That's why drying wood isn't an over night process. Takes time and if you where to take that undried piece of lumber and take to say Colorado. It WILL move. Your lumber like everyone on here knows must be between 10-5%. 12% is pushing it.


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## mdntrdr

Ibangwood said:


> That's a very false statement.



What statement are you referring to? :huh:


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## Ibangwood

Cabinet man, I have a high respect for him and things he makes are beautiful but ya..


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## cabinetman

Ibangwood said:


> Cabinet man, I have a high respect for him and things he makes are beautiful but ya..


I hate to repeat the question...but what statement are you referring to?








 





 
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## Ibangwood

lol ok.. For the 2nd time cabinet Man. My god


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## Ibangwood

Focus on the succession of comments


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## cabinetman

Ibangwood said:


> lol ok.. For the 2nd time cabinet Man. My god





Ibangwood said:


> Focus on the succession of comments


Is this some kind of game for you? What are you saying is false?


















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## Tman1

Ibangwood said:


> Focus on the succession of comments


I think everyone understands you disagree with cabinetman's post. But, it is a two paragraph post. Do you disagree with everything he said or just one statement?


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## cabinetman

Tman1 said:


> I think everyone understands you disagree with cabinetman's post. But, it is a two paragraph post. Do you disagree with everything he said or just one statement?


Grab some popcorn...this could take a while.:laughing:








 







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## Da Aardvark

Starting over here a bit....
There is no sense of planing boards until the wood is to a certain drying level, preferably below 10% moisture content.
A moisture meter is a "must have" item, and can be bought cheap. Mine came from Lowes for under $40.oo.
Air drying won't get it unless you wait years. Generally I'll kiln my stash after it's below 20%. Then most of the warping is done.
I say most, since once it hits a planer, you'v opened up the surface again and things can mov some, but you lessen the odds by getting the m/c. down to a usable level.


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## Ibangwood

I was just saying you must have a moisture meter. Just because the wood stops losing weight doesn't mean it's dry. That's all hence what the example I gave


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## woodnthings

*agreed*



Da Aardvark said:


> Starting over here a bit....
> There is no sense of planing boards until the wood is to a certain drying level, preferably below 10% moisture content.
> A moisture meter is a "must have" item, and can be bought cheap. Mine came from Lowes for under $40.oo.
> Air drying won't get it unless you wait years. Generally I'll kiln my stash after it's below 20%. Then most of the warping is done.
> I say most, since once it hits a planer, you've opened up the surface again and things can move some, but you lessen the odds by getting the m/c. down to a usable level.



A moisture meter will give an "instant" reading, where weighing the stock takes place over a period of time which may not fit in the schedule of the user. I have a lot of 4/4 stock that has been air drying for several years which I bring into the heated shop for a month or so before using. This wood moves very little, if any in the machining process, but I still advocate flipping it each pass through the planer. Some wood just has a mind of it's own and will move, twist or bind regardless of what you do. This includes an occasional plank of kiln dried QSWO and some Cherry in my experience.


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## knotscott

Let the boards dry thoroughly, then let them acclimate in the environment you'll be milling them in for a few days. Most wood is fine if milled to final dimension at this point....as mentioned, milling both sides equally will help reduce movement. Some woods are more prone to movement (elm comes to mind), in which case I'd suggest milling slightly oversized, then let them acclimate another day or two before milling to final dimensions.


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## cabinetman

It's incorrect to assume I meant that weighing wood replaces a moisture meter. It doesn't. In shop conditions if the wood is weighed and stops losing weight, it has become acclimated to the immediate surroundings. This method by no means will provide a percent of moisture content. 

If you don't have a moisture meter, and the wood hasn't gotten any lighter, that's what you have to work with. Moisture meters can be a good indicator, but the wood itself can change from morning to night, especially in areas of wide swings in humidity over short periods of time...like south Florida. If you have a schedule, order your lumber KD.


















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## ETWW

It's obvious that your wood is not dry enough to work. As you removed the surface wood by planing, you exposed the wetter portion underneath and as that wet portion dried, it shrank and caused the board to warp. Air drying of wood does not always take one year per inch of thickness. That's a false statement that is perpetuated on woodworking forums. However, unless you are in the mountain west or desert southwest, wood will need further drying after it has reached air-dry EMC. It's still too wet for indoor use.

Moisture meters, regardless of the type, are good for getting an instantaneous idea of the wood MC and good ones (read expensive ones) are very accurate. Cheaper pin-type meters can give a false MC as they generally measure just the shell MC. They need to have hammer-type pins to reach deep enough to record the inner MC. Ripping a sample where you can check a core, long-grain area will give a more accurate idea of the MC. Also, MC should be checked at multiple places to get a representative reading. Wood dries from the outside-in and at different drying rates along it's length.

Continual weighing of a sample will tell you when the wood has reached or is very close to EMC but it won't tell you the MC and you have to be willing to wait days or weeks. If you use a thermal hygrometer to also track temperature and RH where the wood is being dried, then you can calculate the approximate MC.

THE most accurate method is to use the oven-dry method to calculate MC. You weigh and record a representative sample on a metric scale that reads to at least .05 grams to get the original weight. Then you place the sample in an oven that is pre-heated to 215 degrees. It will take about 24 hours to completely dry the sample. Once dry, weigh and record the oven-dry weight of the sample.

The MC is calculated as follows:

(original weight minus oven-dry weight) divided by (oven-dry weight) x 100

The long-azz link gives specific guidelines for the process.


http://www.google.ca/url?sa=t&rct=j...uYDgDg&usg=AFQjCNEVvdKB5Cme_o1DVQZiRcltDdQgmg


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## Ibangwood

Etww couldn't have said it better


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## Manuka Jock

All of the above good knowledge and advice aside , 
if wood really wants to move , no power on earth can stop it .
We can hold it down for months or years in the stack or as part of a construction , but when it is released , if it to wants move , it will .

Sometimes we just have to get another length of timber ,
and its probably quicker to do so :yes:


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