Bill's Mill Portable Sawmill Service.Based in Jacksonville, Florida

Premier Timber Products Inc

 

   

 

 

 

 

 

 

 

 

 


A Note About Your Lumber

How Much Lumber Am I Gonna Get?

      The honest answer is: I don't have an answer until I'm done cutting up that log. Lots of variables. Rot in the log, sweep, foreign objects, shake, damage done when the tree was felled; I just don't know. I can guess, but it's only an educated guess.

Saw Log Volume Calculator
(Diameter measured small end inside the bark)

Log diameter in inches:   Log length in feet:


Doyle: Scribner: International:

     Lumber quantity is measured in "board feet." One board foot is defined as 144 cubic inches. 1"x12"x1' equals one board foot. So does 2"x6"x1'. Or 1"x4"x3'. Get the idea?

     There are several scales in use that offer a rough idea of how many board feet are in a given log, depending on the diameter of the small end of the log inside the bark, and the length of the log. I use the International scale 'cause that one comes closest to what you can expect to get from the WoodMizer. However, these scales all assume straight, clean, healthy logs. Sweep, holes or other damage will reduce the amount of lumber produced. The calculator to the right   will give you a very rough idea of how much lumber you can expect, considering the limitations I mentioned from a log.

We can often gain more lumber than the international scale suggests from your logs.

Your New Lumber

     The lumber we produce will be rough sawn and green. "Rough sawn" means it will have blade marks on the surface of the wood. The WoodMizer leaves straight tooth marks across the boards; the Lucas leaves curved tooth marks. "Green" means that the wood is still full of the moisture it had in it when it was alive.

     For most purposes it needs to be dried. If your plans are to use it for cabinets, furniture, flooring, etc. you will want to have it planed smooth as well, and possibly kiln dried. We do not provide these services. Please see the section on "air drying lumber" to get you started in this process.

Air Drying Your Lumber

     Lumber milled from a fresh cut log has a lot of water in it. Depending on the species, some wood has more weight in water than it does in dry material weight! The water is removed by evaporation. Just like with drying clothes there are two options for this; one is in a kiln (think "clothes dryer" for clothes) and the other is air drying. (Like a clothesline.) One works faster but requires more equipment and utility costs. The other is lo-tech and slower but much more economical.

     Air drying requires good air circulation around the boards. To achieve this lumber is built into stacks in a way that allows good air flow over and under both faces of each board. This carries the moisture off. Each board in a layer must be the same thickness. Each layer of boards is supported from the one below by spacers called stickers. The stack needs to be raised above the ground, even, and well supported for it's entire length. Drying stacks of lumber are quite heavy!

     Stickers need to be placed at regular intervals and also at the ends of the boards; spacing should be from 16" to a maximum of 24" apart. Stickers need to be placed directly one above the other in order to transfer weight directly to the supports under the stack. If this is not done, the boards will not dry flat.

     The height of the stack is not critical, other than for comfort and safety purposes. The width of the stack is much more important. A stack too wide will not allow enough air flow through it and will not dry properly. Similarly if the stack is placed against a wall, air will not be allowed to flow unimpeded and the lumber will not dry properly.

     The top of the stack should have a row of stickers on it, followed by a rigid covering somewhat larger than the stack. That keeps direct sunshine and rain off the stack. It should also be well weighted to help prevent the upper boards from moving as they dry.

Drying times vary by thickness of the boards, wood species, air flow, climate, time of year... lots of variables.

The above is a brief synopsis. Many volumes have been written on the subject of air drying lumber. Below are a few. Not surprisingly, these experts don't always agree 100% with each other.

The following publications include diagrams of what a good drying stack looks like.

  • http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf
    This is a 7chapter, 66 page document. While it deals more with the commercial aspects of air drying wood, it has a lot of info for the rest of us too. I suppose you could call this rather "dry" reading.
  • http://www.woodweb.com/knowledge_base/Processing_trees_to_lumber.html
    This article is written by Dr Eugene M. Wengert, one of the most respected American authorities on wood. And he has that reputation for a very good reason! However, I take exception to a couple of his statements. First a good, well tuned portable mill, properly operated, will cut lumber just as good as a "commercial" mill and better in many cases. Second, while roofing tar really is a good end-sealer, if you use it on logs you want me to saw you'll either cut it off or get somebody else to saw 'em!!!

    Okay; I'm over my little snit. Other than that, it's a good article.
  • http://www.lcida.org/airdry.html
    Short and to the point. Also has an excellent diagram of what a proper drying stack should look like.
  • http://extension.missouri.edu/p/G5550
    A very good publication. Not real long, but well written. Also has a couple of good diagrams.

 

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