Sawing and Drying

You are not logged in. [ Login ] Why log in
(NOTE: Login is not required to post)

Large Scale Drying

12/13/16       
Sandy Galvin Member

We have a need for large square molding blanks, 17/4 or thereabouts later to be milled to 4" square S4S. We believe we can find sawyers who will cut this for us - presumably out of soft maple - and we propose to purchase a small DH kiln. But we are wondering about drying schedules for these humongous pieces. We need, as much as possible, to avoid splits and checking.

12/14/16       #2: Large Scale Drying ...
Gene Wengert-WoodDoc

The wood will shrink about 1/4" in drying. Then add for twist, cup, bow and crook, especially if the squares are much over 12" long. Splits and cracks can be controlled about 99%. As a sawyer, I would have an issue if you want the squares to be all white wood...my yield will be poor unless I have large logs and then you will have warp issues. You really need to have a test run to study performance and costs.

12/14/16       #3: Large Scale Drying ...
Sandy Galvin Member

We are not very concerned about color. Doesn't have to be white. We are already able to buy this material from a couple of sources - at a hefty price. But around here there is a great deal of available soft maple left from many years ago housing development and we know a couple of outfits with small mills. After we dry the material, it will be sent out to our primary millwork. If we can avoid the cracks, I believe that they can mold it into 16/4 squares without too much difficulty.

So I'm thinking from what you say that we'd want to be thinking about 18/4 wet to start. How about schedules? Are there peculiarities about drying such huge pieces - aside from the typical temperature and humidity checks? I'm thinking a small Nyle dehumidifier and a relatively small box.

12/17/16       #4: Large Scale Drying ...
Don Lewis

I can't think of anyone drying large Soft Maple squares but we have several customers drying Oak that size. And dozens drying Pine. But if you are buying it from several suppliers now and you are happy with what you get, then it must be doable. Are any of your suppliers using Vacuum? If they are and you are not using vacuum, doing some testing makes sense. Ask someone near you that has a dehumidification or conventional kiln to dry some and take a look. If there is defect, figure out why and how to saw to prevent it

12/17/16       #5: Large Scale Drying ...
Sandy Galvin Member

Thanks. We hadn't thought of vacuum drying but that would be interesting. Rather than speeding it up, we have been thinking "slow it down" thinking that an annealing stage might relieve stresses. I built a classic solar kiln about 15 years back and it worked extremely well with 8/4 Soft Maple.

There are obviously numerous outfits drying 12/4 Oak and Ash for baseball bats and some drying other woods for large table legs, though many of the latter are laminated up. The problem with Oak is the roughness and pores, We need something fine grained, heavier than Basswood, and easy to dry. Pine would be good except our market just doesn't like the word, "pine." Poplar might work except a lot of the color of off-putting.

As I said earlier, forty or fifty years ago, local builders used a great deal of Silver maple for plantings around housing and construction projects and these mature trees are the bread and butter for tree cutters around here so there are lots of free logs.

Defecting is not a problem as we are mostly making short lengths; long splits or checking on the other hand are a distinct problem. Nothing for it but to give it a try, I guess.

12/18/16       #6: Large Scale Drying ...
rich c.

Your main source of material is going to be yard trees? Good luck with that, you're likely to see a lot of metal! Around here you get a really short straight log too. 17/4 is a lot different animal to dry than 8/4. Look for a custom vacuum kiln service. A lot less degrade than other kilns. If you trash a couple loads of timber while you learn how to dry the blanks, a custom service charge doesn't seem that bad.

12/19/16       #7: Large Scale Drying ...
Gene Wengert-WoodDoc

Yard trees are known to have excessive stress, called growth stress, that will result in warp during drying, even vacuum. The majority of the pieces will bow, crook and twist. As you get near the center of the log, warp will increase, due to natural shrinkage differences around the center of the log. The risk of a major crack also increases when the piece includes the pith. Pith pieces need the pith centered.

Air drying prior to kiln drying will reduce warp. For well air dried stock, kiln drying times will be over three weeks. Getting the moisture fairly uniform, she'll to core will be a challenge.

Again, I encourage you to cut a thousand pieces as a test run so you can see what will happen as far as warp, drying times, and so on. You can also determine if there are any special quality issues from the ultimate customer. My experience says that this has a number of critical areas that could cause failure.

12/19/16       #8: Large Scale Drying ...
Sandy Galvin Member

Thanks for the advice. We'll see. As for the cutting and sawing, nails and whatnot - not our problem. I may even be wrong about why there's so much SilMap here. Anybody with a gutter can explain the proliferation. But we do know sawyers with logs and we know a couple of tree trimmers that sell them to the former - I just may be off base about the logistics here. Unfortunately, the one outfit with a real, commercial kiln around this area apparently went out of business.

But the notion of air drying first is great - that we can do. We only need about 1000 ln. ft. a year for the 4", so I think we'll just buy the little Nyle and take it from there.

1/4/17       #9: Large Scale Drying ...
fallguy Member

I know a guy that does large, well massive actually, slabs of 3" thick stuff and he is successful by doing a few things. He stickers 1.5" for more airflow. If he stickers narrower, he gets mold. He air dries a minimum of 2 years, but likes 3. He ratchet straps every stack every 18" (he has a router groove in every sticker he uses (just ran all his stickers that way). He keeps his ratchets accessible and in the same area in each stack and actually has a record of when the piles are ratcheted and he reratchets on a schedule. I can't tell you the schedule, but it is more rapid early. And he coats every slab face and ends with a magical clear concoction, someone here probably knows a recipe (something similar to endsealer that slows down the MC loss, but doesn't stop it). And he tried weight on the pile, but the logs would lift any amount of weight. They don't seem to lift their own weight. He also piles the stack in exactly the order cut, but that is done for bookmatching. I don't know how that would affect drying and warping if you got away from that, but by preserving the log in its precut form, any delineation in the sawing is maintained in the stack and not a variable in drying. And any warping stresses seem to be manageable together better than all over which is counter intuitive, but works for him. As Mr. Wengert says, the shrinkage will be great, so you'll need to ratchet the stacks if you want your plan to work. As a word of caution, if you get the wrong ratchet straps they will rust quickly, so he even has a preferred strap(might be aluminum or something with rustproofing). And the stacks must be perfectly level to start. His stacks are all well protected from rain as each slab is worth several hundred or thousand dollars even.

1/4/17       #10: Large Scale Drying ...
fallguy Member

I should add that the selection of the trees used and the sawing is not done blindly. The trees are selected by him and sawn by him. He saws every log to the best pith center possible and he readily rejects any tree with too much lean or any questionable problem. If you just lay a log on the saw and don't even raise the narrower end for even pith, you will have trouble succeeding. And of course if you do this, the outside parts of the slabs end up unused for flat drying...

1/4/17       #11: Large Scale Drying ...
Sandy Galvin

Thanks, Fallguy. However, I can tell you for sure that up to 12/4 the lumber is relatively available as squares. There's a big industry of baseball bat manufacture around here in Hard maple and Ash and though I don't know too much about the details they are getting lathe billets from somewhere. These are rounded to 2-3/4. I buy a good deal of material from some of these bat makers and I assume that they must start with 12/4. or thereabouts.
As to all these potential defects, splits would be a problem, but many of others would be ironed out in the molding machine I should think. We're cutting the final molding into very short lengths, so some sorts of defects are of little consequence.
I probabluy should mention that short lengths are fine with us. anything over 18-24". That might make drying easier.


Post a Response
  • Notify me of responses to this thread
  • Subscribe to email updates on this Forum
  • To receive email notification of additions to this forum thread,
    enter your name and email address, and then click the
    "Keep Me Posted" button below.

    Please Note: If you have posted a message or response,
    do not submit this request ... you are already signed up
    to receive notification!

    Your Name:
    E-Mail Address:
    Enter the correct numbers into the field below:
     

    Date of your Birth:



    Return to top of page

    Buy & Sell Exchanges | Forums | Galleries | Site Map

    FORUM GUIDELINES: Please review the guidelines below before posting at WOODWEB's Interactive Message Boards (return to top)

  • WOODWEB is a professional industrial woodworking site. Hobbyist and homeowner woodworking questions are inappropriate.
  • Messages should be kept reasonably short and on topic, relating to the focus of the forum. Responses should relate to the original question.
  • A valid email return address must be included with each message.
  • Advertising is inappropriate. The only exceptions are the Classified Ads Exchange, Machinery Exchange, Lumber Exchange, and Job Opportunities and Services Exchange. When posting listings in these areas, review the posting instructions carefully.
  • Subject lines may be edited for length and clarity.
  • "Cross posting" is not permitted. Choose the best forum for your question, and post your question at one forum only.
  • Messages requesting private responses will be removed - Forums are designed to provide information and assistance for all of our visitors. Private response requests are appropriate at WOODWEB's Exchanges and Job Opportunities and Services.
  • Messages that accuse businesses or individuals of alleged negative actions or behavior are inappropriate since WOODWEB is unable to verify or substantiate the claims.
  • Posts with the intent of soliciting answers to surveys are not appropriate. Contact WOODWEB for more information on initiating a survey.
  • Excessive forum participation by an individual upsets the balance of a healthy forum atmosphere. Individuals who excessively post responses containing marginal content will be considered repeat forum abusers.
  • Responses that initiate or support inappropriate and off-topic discussion of general politics detract from the professional woodworking focus of WOODWEB, and will be removed.
  • Participants are encouraged to use their real name when posting. Intentionally using another persons name is prohibited, and posts of this nature will be removed at WOODWEB's discretion.
  • Comments, questions, or criticisms regarding Forum policies should be directed to WOODWEB's Systems Administrator
    (return to top).

    Carefully review your message before clicking on the "Send Message" button - you will not be able to revise the message once it has been sent.

    You will be notified of responses to the message(s) you posted via email. Be sure to enter your email address correctly.

    WOODWEB's forums are a highly regarded resource for professional woodworkers. Messages and responses that are crafted in a professional and civil manner strengthen this resource. Messages that do not reflect a professional tone reduce the value of our forums.

    Messages are inappropriate when their content: is deemed libelous in nature or is based on rumor, fails to meet basic standards of decorum, contains blatant advertising or inappropriate emphasis on self promotion (return to top).

    Libel:   Posts which defame an individual or organization, or employ a tone which can be viewed as malicious in nature. Words, pictures, or cartoons which expose a person or organization to public hatred, shame, disgrace, or ridicule, or induce an ill opinion of a person or organization, are libelous.

    Improper Decorum:   Posts which are profane, inciting, disrespectful or uncivil in tone, or maliciously worded. This also includes the venting of unsubstantiated opinions. Such messages do little to illuminate a given topic, and often have the opposite effect. Constructive criticism is acceptable (return to top).

    Advertising:   The purpose of WOODWEB Forums is to provide answers, not an advertising venue. Companies participating in a Forum discussion should provide specific answers to posted questions. WOODWEB suggests that businesses include an appropriately crafted signature in order to identify their company. A well meaning post that seems to be on-topic but contains a product reference may do your business more harm than good in the Forum environment. Forum users may perceive your references to specific products as unsolicited advertising (spam) and consciously avoid your web site or services. A well-crafted signature is an appropriate way to advertise your services that will not offend potential customers. Signatures should be limited to 4-6 lines, and may contain information that identifies the type of business you're in, your URL and email address (return to top).

    Repeated Forum Abuse: Forum participants who repeatedly fail to follow WOODWEB's Forum Guidelines may encounter difficulty when attempting to post messages.

    There are often situations when the original message asks for opinions: "What is the best widget for my type of shop?". To a certain extent, the person posting the message is responsible for including specific questions within the message. An open ended question (like the one above) invites responses that may read as sales pitches. WOODWEB suggests that companies responding to such a question provide detailed and substantive replies rather than responses that read as a one-sided product promotion. It has been WOODWEB's experience that substantive responses are held in higher regard by our readers (return to top).

    The staff of WOODWEB assume no responsibility for the accuracy, content, or outcome of any posting transmitted at WOODWEB's Message Boards. Participants should undertake the use of machinery, materials and methods discussed at WOODWEB's Message Boards after considerate evaluation, and at their own risk. WOODWEB reserves the right to delete any messages it deems inappropriate. (return to top)


  • Forum Posting Help
    Your Name The name you enter in this field will be the name that appears with your post or response (return to form).
    Your Website Personal or business website links must point to the author's website. Inappropriate links will be removed without notice, and at WOODWEB's sole discretion. WOODWEB reserves the right to delete any messages with links it deems inappropriate. (return to form)
    E-Mail Address Your e-mail address will not be publicly viewable. Forum participants will be able to contact you using a contact link (included with your post) that is substituted for your actual address. You must include a valid email address in this field. (return to form)
    Subject Subject may be edited for length and clarity. Subject lines should provide an indication of the content of your post. (return to form)
    Thread Related Link and Image Guidelines Thread Related Links posted at WOODWEB's Forums and Exchanges should point to locations that provide supporting information for the topic being discussed in the current message thread. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related Link that directs visitors to an area with inappropriate content will be removed. WOODWEB reserves the right to delete any messages with links or images it deems inappropriate. (return to form)
    Thread Related File Uploads Thread Related Files posted at WOODWEB's Forums and Exchanges should provide supporting information for the topic being discussed in the current message thread. Video Files: acceptable video formats are: .MOV .AVI .WMV .MPEG .MPG .MP4 (Image Upload Tips)   If you encounter any difficulty when uploading video files, E-mail WOODWEB for assistance. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related File that contains inappropriate content will be removed, and uploaded files that are not directly related to the message thread will be removed. WOODWEB reserves the right to delete any messages with links, files, or images it deems inappropriate. (return to form)