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Thread: Ammonia fuming advice sought

  1. #1
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    Ammonia fuming advice sought

    In a couple of weeks I will be doing my first ammonia fuming on some red oak. In this instance, I am doing it primarily for sterilization reasons (the slab being fumed is 14" thick, 4' wide and 6' long - not a good candidate for the kiln!).

    I'm seeking some advice from some of our members that have 'been there, done that'.

    I have ordered 32 oz of 28% - 30% ammonium hydroxide from a chemical supply house for this purpose.

    I have read that in some instances red oak will turn green during ammonia fuming. Will the green color plane/sand off, or is there a way to prevent it? How bad does it look?

    Also, in the same batch I'd like to fume some 3" x 5"'s, and some 5" x 8's" that I've milled to use for support (I'm planning to make a workbench from the slab), and am wondering how it's best to support the slab and smaller pieces so that the coloration is consistent. If I use 1" wide stickers will there be gaps in the finish?

    Thanks.

    Scott

  2. #2
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    Hello,
    Will the green color plane/sand off, or is there a way to prevent it?
    Green and red "cancel" each other.
    By that I mean a reddish stain should turn the green towards a brown.

    BTW- ammonia won't "sterilize". Wrong pH. Ammonia is a weak base.
    You need to go the other way - on the acid side.
    Bleach will "sterilize".

    Depending on what you're trying to "kill", you might end up making a more comfortable "home" for it.

  3. #3
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    Rich, thanks for the feedback.

    Re the ammonia fumes not sterilizing the wood, this thread indicates otherwise:

    http://www.sawmillcreek.org/showthre...t=killing+bugs

    Perhaps we're thinking in different terms with respect to the word "sterilize". We use this term when kiln drying to refer to the heat schedule used at the end of a kiln cycle to kill any bugs, larvae, eggs, etc in the wood, which is the context that I am using it in. Perhaps you're thinking in terms of killing bacteria, which is different than what I intended?

    Thx.

    Scott

  4. #4
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    http://musial.ws/fuming.htm

    Orange shellac will help with the green color.

  5. #5
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    Hello Scott,
    Yep - I'm thinking bacteria like stuff or fungal.
    Ammonia is quite deadly on some "critters" especially soft skin like frogs larve and worms.

    Good tip also on the orange shellac.

  6. #6
    Scott,

    How did this turn out? I have a red oak chest of drawers that I would like to fume. But have heard that the results will not be pleasant.

    James

  7. #7
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    Quote Originally Posted by Rich Engelhardt View Post

    BTW- ammonia won't "sterilize". Wrong pH. Ammonia is a weak base.
    You need to go the other way - on the acid side.
    Bleach will "sterilize".
    Household CHLOROX has a pH of about 12 .. contains sodium hydroxide and sodium hypochlorite .. actually, a pretty strong base .. not an acid.
    FINISHING : NO ART & VERY LITTLE SCIENCE ... just a learned skill that requires a bit of practice and patience ... anyone can learn it.

  8. #8
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    Fuming for color is hit and miss. Using dye gives you more control and is much safer.
    Scott

    Finishing is an 'Art & a Science'. Actually, it is a process. You must understand the properties and tendencies of the finish you are using. You must know the proper steps and techniques, then you must execute them properly.

  9. #9
    Hi Scott,

    I have thought about dye. However I am concerned about fading and don't like the idea of dealing with raised grain from water based dye. What dyes are there that do not fade. I currently have some TransTint Dark Vintage Maple and Transfast water soluble Dark Mission Brown. These were purchased for this project. However I kind of wanted to make this authentic and I am concerned about fading since this chest of drawers is intended to be an heirloom.

    To complicate maters. The top and four leg posts are QS white oak and all other components are QS black oak not red oak (not sure if that maters). I have some boards in a 5 gal pale at the moment and the white oak has got a deep chocolate color but the black is more green/gray and pale by comparison.

    I am using janitor strength (10%) ammonia. So the dangers are much less. 8 hours in the pail was enough to get the white oak nice and dark. I was thinking perhaps I could wipe the black oak with the ammonia prior to fuming. Therefore giving it a head start. But I am very unsure about this. Since it could lead to blotching. I am open to suggestions.

    My wife will be picking up some Minwax Antique Oil today. Since I understand its color will combat the green color of the fumed oak. I currently have at my disposal BLO, Watco Danish oil in natural, Med Walnut and Dark Walnut. I also have an assortment of Minwax Gel stains (many). As well as some blond shellac. I do intend to get some Amber, Orange , or Garnet shellack for this project. Bye the way. Is Amber and Orange the same color when it comes to shellac?

    Any and all suggestions are welcomed.

    James

  10. #10
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    Quote Originally Posted by James White View Post
    Scott,

    How did this turn out? I have a red oak chest of drawers that I would like to fume. But have heard that the results will not be pleasant.

    James

    Hi James. The project turned out well, and I subsequently milled the giant slab into smaller slabs for Roubo-style workbenches. I ended up using 28% ammonia, and although I was primarily interested in killing any little critters, some of the red oak turned a beautiful green/grey color. It did not darken up anywhere near the white oak though (I put some WO sample boards in with the RO).

    One nice thing about dye's is that they don't penetrate the medullary rays, so if you have any pieces with a lot of ray flect that you want to embellish, the dye is a good way to go.

    Best of success to you on your project.

    Scott

  11. #11
    Thank you for the feedback Scott.

    Here are some photos. Left: 22 hrs fumed, Center: 22 hrs fumed one coat blo with shellac applied before blo cured, right: 8hrs fumed two coats blo and shellac applied blo uncured. The dark stain in the left corners are were the boars wicked up some ammonia (not intentional).P5266361.jpgP5266369.jpg

  12. #12
    Does anyone know what is in Minwax Antique Oil? Is it true that it will cancel out the green?

    James

  13. #13
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    Minwax Antique OIl is an oil/varnish mix of the typical amber coloration. It's the color of the top coat not "what's in it" that will neutralize a green shade. Green + red is a neutral brown. Green + yellow is a yellower green.

  14. #14
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    >>>> Is Amber and Orange the same color when it comes to shellac?

    No, amber is a sort of straw color (yellowish) and quite light. Orange (garnet) is darker and orange.

    Also, there is not much difference between Watco Danish Oil - Natural and Minwax Antique Oil. Both are oil/varnish mixtures with linseed oil as their base.
    Howie.........

  15. #15
    Thank you both. I will be going with the water based Transfast in the Dark Mission Brown. The white and black oak fumed up a bit too different to use fuming. I did some test boards with the dye and I like the look.

    I plan to spray the dresser with water today. Then tomorrow I will sand with 220 or 320. I am not sure what is appropriate. Then spray with water again just before applying the dye. Question is should I sand after that dries. I still don't know what color shellac to go with. Amber or Garnet? What would you use?

    So Orange and Garnet are the interchangeable terms?

    James

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