Warpage in maple door panels

      Despite a careful glue-up, a woodworker gets warpage in door panels. June 14, 2000

I recently made some raised-panel doors out of maple.

When I glued up the wood for the panels, I made sure the grain was opposing, but the panels still warped after planing/sanding to 5/8-inch-thick. The warpage was very noticeable, but not bad enough to trash the doors.

When the doors were complete, I left them in an unheated room and went on vacation for two weeks. When I got back, some of the stile-to-rail glue joints had cracked/split. I took the doors inside and repaired the damage.

My questions: Will this sort of thing keep happening even if the wood is inside, where the temperatures are more stable? How could I have prevented this? I don't have a heated shop, therefore the wood is pretty cold (due to winter) to begin with. Could this be my problem?

Forum Responses
The problem is moisture change (which is directly related to relative humidity change), not temperature change.

Warp only occurs if the moisture changes. You need to get the veneer and the solids at the correct moisture content for the job's final destination, then assemble the doors.

One place to learn more is from the video "Moisture and Wood" from the Wood Component Manufacturers Association.
Gene Wengert, forum moderator

If the wood is not allowed to become stable in the environment where the part will be used, problems including warpage can occur.

In the case of warped wood, the problem is related to the moisture in the wood. The way the wood was or was not dryed will directly relate to the way the wood works. I have run wood that was straight before it was run through a shaper, planer or moulder and after being run the wood bowed enough to look like a rocking chair rocker.

If the wood is frozen when you process it, the wood will cut different and surface will fuzz. This may cause the glue joint not to hold well.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
Wood moisture content is why moisture meters are sold. Various types are available for checking percent moisture in wood before you buy. Shop environment can be a contributor to moisture content. This is also controllable and affects what you measured before. Once sealed, wood can be fairly stable for years.

Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?

Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Architectural Millwork: Doors and Windows

  • KnowledgeBase: Cabinetmaking: Cabinet Door Construction

  • KnowledgeBase: Woodworking Miscellaneous: Woodworking

  • KnowledgeBase: Knowledge Base

    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.

    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2016 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB

  • WOODWEB - the leading resource for professional woodworkers

      Home » Knowledge Base » Knowledge Base Article