I seem to be a bit confused. What I’ve always done is joint my wood, plane to thickness, rip to size and then use. I was told, by a professional, that is incorrect. That I should be ripping to slightly over-size, then jointing, then planing, then jointing again, then ripping to final size. He explained it had to do with wood movement. I have two situations where I’m having problems. One, I have some lumber that has been stored outside for years, under a shed. So, I ripped off a piece, jointed it, planed it, cut to size and it moved. Second one, I’ve had some lumber, that I’ve had for years, in my shop, that I’ve jointed, planed to size, ripped to size and it moved. What is going on? What is the proper sequence?
I realize this may be a basic question, but I’m a little confused. Thank you.
Replies
I always mill slightly oversized, let the stock acclimate to the shop, then final mill just prior to starting the joinery. It always move after the first milling, in fact, it will always move, (hence frame and panel construction).
robin,
There are different ways to arrive at the same end. What I like to do, is to rough cut the stock oversize first. Maybe an inch or so over long, and 3/8" over wide. This will give a piece with internal stresses a chance to relax a bit, and makes it possible to use stock that would be too crooked to dress to thickness if left full length/width. It's not a bad idea to let stock rest a day or two at this point.
Then I face joint, & dress to thickness. If you need to take a lot off, it is helpful to do this in two stages. For instance, if I'm taking 1" stock to 1/2", I'll stop at 3/4" or so, stacking the stock so air can freely circulate around it,and finish planing in a day or two, re- face jointing first if necessary.
Joint one edge, rip to 1/16" over wide, & joint to width.
Cut to final length.
My neighbor builds kitchen cabinets. His first step is to face joint the full length boards, then dress the full width boards to thickness. He'll cut off and discard any stock that doesn't make thickness. Then he rips to width, and cuts his face frame stock to length. He uses standard dimensioned pieces over and over, so he stockpiles these parts (stiles, rails, door frames, drawer stock), discarding any pieces that warp or twist.
There is more waste involved with his method, but it is more efficient for him, since all his stock is the same thickness, and much is the same width (face frames and door stiles/rails). It's easier for him to just go to the stockpile and pull predimensioned stock than to have to continually repeat the same operations over and over.
I'll bet others have their own routines as well.
Regards,
Ray
Robinlynn, where have you been? We just had this discussion. Sorry, I can't direct you to it but here are some highlights.
You are looking to take a rough sawn piece of lumber and surface all the edges and faces to a smooth and uniform size. In addition, you want the opposing surfaces to be parallel with each other and 90° to each other. Each milling step is done to compliment the other surfaces and achieve the desired results. The process follows a sequence that does one surface and then does the opposite surface so that they can be parallel to each other. Plane a face, flip it over and bring the other face parallel to that one, straighten an edge and make the other edge parallel to that, cut one end and cut the opposite parallel to that.
If you start with an edge on the jointer, what does that edge reference to? You can get the edge straight but it won't be 90° to your finished face because you don't have a finished face yet. The first step is to flatten one face. Once you have a flat surface on the face you can reference all the other surfaces to this one.
The second step is to plane the board to thickness. The planer, automatically, will bring the opposite face parallel to the first one. It's a good idea to be aware of how much material you are removing and try to take an equal amount off each face. This usually means, that in planing, you will flip the board and take some off each face. If you take more off one face than the other, it will often lead to warping. This has to do with the dynamic tension that is inherent in the cellular structure of the wood.
The next step is straightening an edge. Because the two faces are smooth and parallel, you will not only get the edge straight but when held against the jointer fence, it will also be 90° to the face.
Next, you rip the opposite edge on the table saw. The blade is at 90° and the fence is parallel to the blade, therefore the board will have a 90° edge and be parallel to the side that went against the fence. If you have a wide board that you are ripping into smaller pieces, the dynamic tension of the lumber can come into play and the ripped pieces can warp. The way to solve this, is to rip the wide board to a size that is a little larger than your finial dimension before you start the milling. In this case, you may want to join an edge as a first step, just so you will have something straight to put against the saw fence.
In some cases, you may want to remove the saw marks from the ripped edge. Typically we go back to the jointer for one pass. You need to know that you will be doing this and set the saw fence to account for the depth of the jointer cut.
Now you can cut your ends. I'm glossing over some important techniques in using the various machines. I'm guessing that you already know how to use the jointer properly for both sizing and flattening and that you understand how to read grain direction and can see inherent problems with particular pieces of lumber.
You didn't specifically say how your wood was moving. You can cause a piece to move with improper milling techniques but it's more likely due to moisture and perhaps storing and handling procedures. Moisture content is a big factor. If your lumber has been outside, stacked over a dirt floor and the humidity has been high, you can expect the boards to have high moisture content. The ideal moisture content is 6%-8%. You need a moisture meter to determine this but you may not have one. Even with one, it's best to acclimate the lumber to the shop.
You need good air circulation around your lumber before, during and after the milling. In high humidity situations, like I'm facing right now, I will stack the lumber with evenly spaced stickers, up off the floor and run a fan on the pile for as long as I can. As I progress through the milling, I will return the pieces to a stickered pile and keep the fan going.
The big issues are to, take equal amounts off both sides when thicknessing, avoid ripping wide stock after milling, control the moisture content and allow air circulation.
Edit: I found the past discussion. If the link doesn't work you can go to advanced search and put in the discussion number.
http://forums.taunton.com/tp-knots/messages?msg=24018.8
Beat it to fit / Paint it to match
Edited 6/17/2005 11:26 am ET by Hammer
What is going on? What is the proper sequence?
the others have explained milling sequences; 2 thoughts came to mind. Your stock taken from outside sounds like it didn't have time to reach equilibrium with your shop conditions.
No excuse for the 2nd board not being in equilibrium... only thoughts there are unequal stock removal from each face of the board or possibly some reaction wood...
Mike Wallace
Stay safe....Have fun
You must know that if you are planning to use that lumber in the shed, that most likely the MC will be around 12% and will need more than a couple of weeks in the shop to dry on down to 6 -8% which is where it will end up once it ends up in a controlled atmosphere almost everywhere.
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