Avoiding Iron Stain when Steam-Bending Red Oak
Oak and other high-tannin woods react with water and iron to create black staining. Here's how to prevent it. December 8, 2006
Question
I have a proposed job that requires steam bending red oak. My client is concerned that the oak will develop black blotches. In previous jobs involving steaming red oak I haven't had problems. Was I just lucky or should I be concerned?
Forum Responses
(Furniture Making Forum)
From contributor D:
You have to keep the wet wood away from all iron. The ferrites in the iron/steel will react with the tannins in the oak and cause an ebonizing stain. It’s great when you want ebonized, terrible when you don't want it. Use a plastic steam chamber, stainless boiling pots and parts, and clean water. Then do a trial run to insure the results.
From Gene Wengert, forum technical advisor:
Iron tannate stain can be removed instantly with oxalic acid.
From contributor B:
Contributor D is correct. It’s not so much the wetness that will cause the spots but the iron. Have you ever noticed if you get a drop of blood on oak that it will turn black when it dries? That’s because of the iron that is present in your blood. Although I will say I have experienced dark blotches as a result of the wood getting wet, I’m talking a bottle of water being spilled on them and not just a run through the steam box.
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: Knowledge Base
KnowledgeBase: Furniture
KnowledgeBase: Furniture: General
KnowledgeBase: Woodworking Miscellaneous
KnowledgeBase: Woodworking Miscellaneous: Bending Wood
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.
|
