What is "fuming"?

      Explanations of the process of fuming wood for color. April 11, 2001

We have a finish spec which reads "white oak, bleached and lightly fumed". What is "fumed"?

Forum Responses
Fuming is a process where the fumes of ammonia (a gas) are used on woods that have natural tannin. The ammonia fuming depends on how much tannin is in the wood. The fuming process is used to turn the color of these woods into other shades of yellow and honey-browns. Oak, chestnut, redwood and hemlock are high in tannins. The color the wood turns will depend on the strength of the ammonia and the length of time the wood is fumed.

A word of caution: You need to be very careful using ammonia. This should be done in an outdoor tent. Before you begin, spend some time researching safe fuming.

Why would you want to bleach and fume the same piece? One will lighten/burn and the other will darken/age.

Bleaching and ammonia can be a dangerous combination, unless you completely neutralize the bleach with a good "washing with clear water."

You may want to try using a dye stain to achieve the color, instead of going through the bleaching and fuming process on a big job. You could make up a couple of small samples, doing a bleach, then a good water wash, allow to dry, then do a fuming in a small plastic tent (outside) to see the colors you can get from the fuming.

It may be easier/safer to first bleach the wood and then use an NGR to replicate the look.

I hope you're not dead yet. If you are still breathing after the above advice, fuming has several definitions in finishing. The first is as explained above. The second, to spray a "fume" coat, is a light misty spray. The third and probably the most likely is to "fume with a wire brush." Simply put, wire brushing the oak to open the grain.

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: Finishing

  • KnowledgeBase: Finishing: General Wood Finishing

  • KnowledgeBase: Lumber and Plywood

  • KnowledgeBase: Lumber & Plywood: Buying

  • KnowledgeBase: Lumber & Plywood: Wood Identification

  • 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 © 1996-2021 - 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