Replies

1. 
   UncleDunc | Jun 18, 2004 11:02pm | #1

   Never saw any red. All the stuff I fumed came out with green highlights. I've seen other people report the same thing, but I can't remember where.

   And thanks for confirming my experience that industrial strength ammonia is not required. :o)

2. 
   RickL | Jun 18, 2004 11:27pm | #2

   I think you are looking for something that's not there. We fume in the freezing cold in winter as well as the hot summer  and use spent ammonia from from blueprint machines as well as a 100 lb tank of anhydrous ammonia and get the same thing you get. Some stuff goes green for a bit but comes back to brown.

3. 
   jonsherryl | Jun 18, 2004 11:28pm | #3

    >>"Is there anything else I can vary to affect a shift in the color?"<<

   Since the fuming process is a chemical reaction between the ammonia and the wood's extractives (primarily tannic acid), the resulting pigmentation is a function of the species. There are subtle differences in the color ammonia imparts to various woods. For example, most of the white oaks transition to a rather dead brown with yellowish or gold undertones, as you've discovered. The red oaks seem to maintain a little more of their pinkish hue (pigments they possess for other chemical reasons regardless of the ammonia)...while chestnut tends to develop gray or even greenish highlights when fumed.

   ...So, I guess you have several choices: you can move to a species that produces the color you want...or you can doctor up the color on a post fuming basis with either stains applied directly to the wood or incorporated into the top coat...or you can experiment with altering the chemistry of the wood prior to fuming. In other words, introduce other chemicals; primarily other sources of mild acids, tannin or other likely contributors to pigment formation, which would include some metals and/or minerals. For example, I've experimented with a brushed on wash of strong tea when working with some species that wouldn't otherwise react to ammonia...and the results differ depending on the species.

   In the final analysis though...as you complicate the finishing process with applications of other substances...why bother with fuming? you can achieve virtually any color you please with stains. To me, the merit of fuming is to achieve the unique color that species produces when fumed. The motive for doing it is, therefore, based more on achieving a traditional look appropriate for that wood, rather than because fuming is a convenient or particularly pleasant way to introduce pigments. Those are the least of its charms.

1. 
   yotonyb | Jun 19, 2004 07:19am | #4

   Thanks everyone!

   UncleDunc...I mentioned before that some of your earlier posts on this topic served as motivation and guidance to try this. I never doubted it could be done with household ammonia. I knew it would take longer, but it does work!

   Rick...that's what I suspected...the more I read about it, the more I realize my expectations were wrong.

   Jon Arno...thank you for taking the time to respond! Your response is valued greatly. And I agree with you...this was done specifically because I wanted the unique effects of fuming. I do like the color I'm getting. And the results are consistent which was a big concern when I started. I just wondered if there were any environmental variables that could be changed to shift the color. Adding chemicals, using another dye or stain, these simply add steps I'm looking to avoid right now. I already know that I can achieve the reddish hue that I like with one of the Mosers aniline dyes. So if I'm selective with my material, choose heartwood and use pieces from the same board, I should continue to get even, consistent results from fuming.

   And since my first post earlier today, I decided to limit the process to fuming and topcoating. I'll save the experimentation of adding additional steps for a later date.

   Tannin is typically available in powdered form from a store specializing in winemaking or brewing. I'd like to experiment with brushing a solution on some different woods and looking at the results after fuming. Intersted in seeing how the sapwood of white oak responds to that.

   Gotta go...gotta check the steel wool soaking in the jar of vinegar...

   tony b.

   Edited 6/19/2004 12:22 am ET by YOTONYB

1. 
   AlbionWood | Jun 19, 2004 07:20pm | #5

   Tony, my experience with fuming white oak is pretty consistent with yours.  I can adjust the tone to some degree by limiting the exposure time - getting a lighter color with shorter exposure.  The tone is a cold brown, but it warms up with oil, and you can get some reddish tone with garnet shellac.  The "Rohirric" chest I made was done that way.

   I suspect part of the problem is the modern "Mission-style" pieces, that are finished with stains, are often a lot redder in tone than the original Stickley pieces were.  Your expectations may be influenced by that.

   I think fuming does offer certain advantages over staining.  One, it does not highlight the open grain; two, it penetrates deep into the wood, so the color will survive abuse and even refinishing.  The first reason is the primary one for me - all my attempts to dye or stain white oak resulted in the color lodging in the open pores and highlighting them to a degree that I found undesirable.  I understand that spray application can resolve this, but I don't do enough finishing to justify that investment (yet).  Speaking of investment, fuming is also extremely cheap!

   One possible disadvantage is that fuming actually reduces the contrast between the ray flecks and the ground - the opposite of staining."Everything should be made as simple as possible, but no simpler."  A. Einstein

   http://www.albionworks.net