Fuming

Just read an article in a pommy wood mag about fuming.

Apparently some woods that are high in tannin, eg English Oak, darken in the presence of ammonia. So if you put your workpiece in a plastic bag with a container of ammonia, over a few hours it will significantly darken the wood.

Unlike staining, it darkens very evenly, even on end grain.

So are there any Aussie hardwoods that have a high tannin content that would lend themselves to this process?

Has anybody ever tried it?

I'm just curious.

Craig

Not very scientific but ..... woods that have stained my hands black:
Kwila - a lot !!
Jarrah - a little
Tas Oak variants - a little

The black stain would indicate tannin.

Took SWMBO to Toronto Woodshed on Saturday to pick her Timber for the bedroom suite. Ha, she picked South American Rareasrockinghorse **** at $10,000+ a cubic metre. No sweetheart, I'd rather run a handgrenade through my thicknesser than trust myself to work with timber that valuable.

So being the cheapskate that I am I gave some Blackwood (actually it's red :confused: ) a coat of 5% Ammonia and watched it turn into a nicely grained walnut. (Thanks to Neil and his Bible) :D
Kind regards
Termite
ps. watch the bloody fumes :eek:

Quote:

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Originally Posted by Termite

So being the cheapskate that I am I gave some Blackwood (actually it's red :confused: ) a coat of 5% Ammonia and watched it turn into a nicely grained walnut. (Thanks to Neil and his Bible) :D

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Does Neil cover fuming in The Good Book? :eek:

I must have missed that.

Must be time for a re-read :)

Craig

[QUOTE=craigb]Does Neil cover fuming in The Good Book? :eek:

From memory he doesn't, but he does throw out a heap of tantalising hints to get you to experiment. Having just been satisfied with an ammonia trial I did on the weekend I'm now about to experiment with Potassium Bichromate.
Kind regards
Termite

Termite,

Re-reading your post, it sounds like you applied the ammonia directly to the wood?

The article I read said that you placed the wood inside a sealed plastic bag together with an open container of ammonia. The wood then absorbes the fumes over several hours.

You control the amount of darkening by the amount of time you leave it in the bag.

Was the darkening of the blackwood instantaneous or did it take a while?

Cheers

Craig

[QUOTE=craigb

Was the darkening of the blackwood instantaneous or did it take a while?

Craig[/QUOTE]

Craig, the darkening took about 2 minutes using 5% household ammonia applied direct to the timber. (it went through some funny colours in the process :eek: ). I have a feeling that the fuming method may need stronger ammonia. Then again being new to this process I might be wrong, it has been known. :D
Kind regards
Termite

psst, psst, hey termite, whered ya get the Potassium Bichromate man?

Does it make ya wood go blacker or what?

I tried household ammonia a long while ago and it just isnt strong enough for fuming, pity as many of our natives are tannin rich. Wonder how it would go on the white sapwood of blackwood!

kevin ley uses an old freezer for fuming and has excellent results.

The Arts and Crafts movement in the US used to use a lot of fumed oak, so there's a bit of info out there.

Most sources I have seen involve building a "room" out of plastic, and leaving the completed piece exposed for varying lengths of time.

There was a good article on the subject in FWW October 97 for those interested.

Cheers,

P

I have used this technique several times with varying results.

Firstly you need to use Ammonia much stronger than the househole variety.
I had a supply of I think it was described as 90 proof used in architectual plan printers. Now this **** is lethal if you dropped a cupfull in a workshop I would give you a 1 in 10 chance of getting to the door alive so safety gear is a must gloves goggles and cartridge respirator.
I found that English Oak responded much better than US Oak some of that just turned a sickly green colour.
Have not tried it on Aust timbers but I guess the most tanin filled would be blackwood.
I used to just build a box out of thin offcuts and cover in plastic sealed with tape placed a few dinner plates full of Ammonia at the bottom and run like hell.

Different

I am here in the US, so White Oak is plentiful. I use the "fuming' method with Quartersawn White Oak. I build a simple "tent" out of 1x2 pine strips, covered with sheet plastic. I make one side of the 'tent' a flap so that I can get in an out fast. I use a respirator specific to gasses, and a set of swimming goggles to protect the eyes.
Put the piece in the tent, lay out several small jars, put the ammonia in the jars, close the flap...go about your way. Place several cut-offs in the tent to use for sampling the tone. That way you do not have to stay in the tent, or disturb the piece.
The ammonia is quite available at local blueprinting shops. Speak to any architect to get their service...Cheap stuff.
I let my recent desk stand for about 3 hours...a nice rich brown. Not too dark. Over that I used an amber shellac- 2 coats...then dark wax to fill the open grain...beautiful...
For curiousity, I cut one of the sample cut-offs in half. The "coloring" had gone through about 1/8 inch. Which means that you can do some light sanding if needed without worry.
I wouldn't hesitate to do it again.
P.S. - I have the luxury to do this process outdoors...I wouldn't try it indoors.

Quote:

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Originally Posted by Different

I have used this technique several times with varying results.

Firstly you need to use Ammonia much stronger than the househole variety.
I had a supply of I think it was described as 90 proof used in architectual plan printers. Now this **** is lethal if you dropped a cupfull in a workshop I would give you a 1 in 10 chance of getting to the door alive so safety gear is a must gloves goggles and cartridge respirator.

Different

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Actually concentrated ammonia is even more dangerous than that. There is a famous scientific lab here in canberra designed for dangerous stuff, the only thing they think that the air system can not handle is someone dropping a bottle of Ammonia (just 2L of the stuff) in a building that covers the better part of a couple of acres and several levels.

My advice would be work with the most dilute stuff that gives you the results, wiping would be more effective but harder to control.

[QUOTE=Harry II]psst, psst, hey termite, whered ya get the Potassium Bichromate man?

Havent got any yet.
regards
Termite