Ammonia fuming advice sought

[Scott T Smith]

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

[Rich Engelhardt]

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.

[Scott T Smith]

Rich, thanks for the feedback.

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

http://www.sawmillcreek.org/showthread.php?t=111929&highlight=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

[Stephen Musial]

http://musial.ws/fuming.htm

Orange shellac will help with the green color.

[Rich Engelhardt]

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.

[James White]

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

[Bob Wingard]

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.

[Scott Holmes]

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

[James White]

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

[Scott T Smith]

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

[James White]

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).195937195938

[James White]

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

James

[Steve Schoene]

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.

[Howard Acheson]

>>>> 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.

[James White]

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

[Jerome Hanby]

So Orange and Garnet are the interchangeable terms?

James

I thought Orange and Amber were the synonymous terms... Be good to find out if I am wrong!

[Rich Engelhardt]

Household CHLOROX has a pH of about 12 .. contains sodium hydroxide and sodium hypochlorite .. actually, a pretty strong base .. not an acid
Correct...
My post was unclear in that regard.
I'd intended that ammonia (a base) is a weaker base than Clorox.(another base).
A weak base, such as ammonia (pH of ~11) isn't as effective as a weak acid - such as vinegar(pH of ~3) w/ neutral being a pH of 7 as a "sterilizing" agent.

[Howard Acheson]

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

Sand with 320 grit. Mount your sandpaper on a felt cushioned sanding block and sand in the direction of the grain. Sand very lightly--ultimate smoothness is not important at this stage. Smoothness comes by smooth sanding after applying the first coat of clear finish. No sanding is advised before that.

Why are you going to spray with water again? Last time I used a waterbased stain, I sprayed onto dry wood. Wetting the wood can lead to uneven penetration of the dye.

Yes, in shellac, garnet = orange.

What is your top coat going to be? If you are going to use a poly varnish or a waterborne finish, your shellac must be dewaxed.

[Steve Schoene]

As has been mentioned, no reason at all to spray oak with water just before dying. You may have seen some advise about doing that, BUT the context was different. That is a technique that might be used on very blotch prone woods to reduce blotching, with the water acting as a mild pre-dye conditioner. But oak doesn't blotch, so the water has nothing to do that would be positive. And, while raising the grain by wetting and then sanding after it has dried is a tradtional technique, it really is over rated. Sand just a tiny bit too much and you will have grain raise anyway. It is a lot easier to ignore that, just apply the dye, let it dry, and then apply the first coat of the top coat, right over the roughened raised grain. Then when that has dried you can sand off the raised grain. It will sand more easily since it has been stiffened by the first finish coat.

[James White]

Thank you both for the advise. Yes I read an article on applying dye and it recommended spraying with water to even out the dye absorption. I like the idea of sanding after the sealer coat. Makes sense to me.

I am not sure about top coat. I was considering just the shellac and wax. I don't want a plastic look. Perhaps lacquer would be good. I don't have very much finishing experience. Mostly brushed or wiped on poly over oil. I have only used shellac once and sprayed lacquer once. I am terified of wrecking this.

Any recommendation on what color shellac to go with? I now have BTC in blond, amber and garnet. I would like to have a classic Arts and Crafts look. Every thing I have read just says shellac but never specify what color.

James