Ammonia finishes

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Forum topic by Chipy posted 11-04-2011 05:04 PM 2056 views 0 times favorited 6 replies Add to Favorites Watch
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374 posts in 2011 days

11-04-2011 05:04 PM

Topic tags/keywords: tip question resource

I am strongly considering building a Morris chair and stool and would like to try an ammonia fume finish.Has any lumber Jocks finished a piece with this method and was it difficult? I read were the components were fumed then assembled is this the best procedure or complete the piece and then ammonia fume?Any help would be great thanks.

6 replies so far

View DS's profile


2145 posts in 1838 days

#1 posted 11-04-2011 05:45 PM

What I know is that the process is toxic and can be fatal if done improperly.
Most people construct an air-tight tent to place the work in. The ammonia reacts with the tannin in the wood and different species of woods react differently to the ammonia.

I’ve heard, since the reaction goes through the wood and not just on the surface, that you can buy pre-fumed lumber from certain suppliers and start with that instead of fuming the completed project. I’ve never actually tried this so I couldn’t be sure.

My preference would be to take the piece somewhere that is properly set up for this type of finish and pay them to finish it for me. I suppose I just have too much to live for to risk making a mistake.
(I tend to mistakes from time to time, so I also tend to avoid doing things that can kill me if I make a mistake, that is, if I can help it.)

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View KnickKnack's profile


1062 posts in 2984 days

#2 posted 11-04-2011 06:32 PM

I’ve done quite a bit of fuming – both pre-assembly and post assembly.

Sure, it’ll kill you if you breathe it, so don’t.

I fume small items in a large plastic bag. Large things (I did a chest of drawers once) I do in the plastic “bag” that a mattress came in – it’s huge. I always do it outside in a shed (or the small things in an outside bread oven) – make sure your animals, if you have any, can’t get in – they’re inquisitive.
If you fume pre-assembly make sure you leave at least 24 hours, better more, for it to “gass off” – ie, for all the ammonia to dissipate. Good for your health and I’ve had glue issues trying to glue wood that was still smelly.
If you fume post-assembly be careful of glue marks – you will be able to see anything you missed like a sore (and pale) thumb afterwards.
Oak is the “classic” wood, of course, but don’t assume other things won’t darken up a bit too – I personally like what it does to ash – it’s subtle but noticeable. Pine, too, especially the pinkish heartwood changes. If you are mixing woods, test a bit first in a small bag to see what happens – you need to fume and apply some finish to see where it’s going to go. You also need to keep an eye on your stock – one piece of oak might go dark as night but another do almost nothing.
Personally I like it – its exciting to see the wood, or a completed piece, change, and I really like the depth of colour that you get – imho much better than stain.

-- "Do not speak – unless it improves on silence." --- "Following the rules and protecting the regulations is binding oneself without rope."

View Chipy's profile


374 posts in 2011 days

#3 posted 11-04-2011 07:28 PM

KnickKnack Wow! great info.I think I will give it a try but the first thing I will do is get a hold of a respirator!What do do after fuming ie. polyurethane, shellac etc.

View tenontim's profile


2131 posts in 3162 days

#4 posted 11-04-2011 08:16 PM

Ditto most of what’s already been said.
Make sure your respirator is approved for ammonia. It’s not the normal cartridge that comes with most respirators.
Use 29% ammonia, or stronger. The household stuff won’t work.
I like to do my fuming post assembly. As mentioned, make sure you get all of the glue cleaned up before.
Another thing: sap wood doesn’t contain tannin, so it won’t change color. If you want this effect, no worries.
I don’t like it in my furniture, so I check closely to ensure that I don’t use any when cutting out pieces for the furniture. I also cut a six inch piece off of the end of each board. I number the piece and the piece it came from and do a test fume, in order to make sure the pieces are all going to fume the same color. Unless all of your wood came from the same tree, or the trees were in the same vicinity, the tannin content can be different.
Also put test pieces in with the furniture, and you can remove one every couple of hours until you get the color you’re after. Max darkness will be obtained after about 24 hours. Any more time than that won’t make much difference in the color.

View ETwoodworks's profile


92 posts in 2111 days

#5 posted 11-04-2011 08:30 PM

Use 29% ammonia, or stronger. The household stuff won’t work. This iis not exactly true. I have used 5% household amonia on small stuff and with enough time and amonia it will work. At ACE I also found some 10% that worked good it just takes more of it and more time.

-- Building quality in a throw away world.

View planeBill's profile


506 posts in 1827 days

#6 posted 11-07-2011 05:37 AM

I absolutely suck at staining, especially oil staining, so I like fuming. As has been said, it will kill you if you breath it, so don’t. When I do fuume I get everything, and I mean everything ready to go before opening the ammonia. My fuming containers come in the forms of boxes from my work. I happen to work in a retail furniture store warehouse. I can pretty much find any size box I need for anything I care to make. I then shrinkwrap the box or buy a roll of packing tape and enclose the box with the shrinkwrap or tape and then cut where the piece will be going in. put the piece, or pieces in, set a small glass container on the bottom of the box, dawn my giant rubber gloves and grab, very carefully, the ammonia. Now, I do wear a full face shield but thats it. I don’t know about everyone else but I can hold my breath for what seems like a long time. I saturate my blood with as much oxygen as I can get in there. Mind you, at this point the only things that needs doing is pouring the ammonia and closing the box containing the piece being fumed. I pour the ammonia, close the box and either give a couple more wraps of the shrinkwrap or tape up the opening with the tape. I’m sure my fuming “tents” are not completely airtight but I can never smell any outside the box.
As stated already, it’s the tanic acid in the wood that reacts with the ammonia and for this reason you should really try to get all of the wood for your project from the same source and preferrably from the same tree because no tree contains the same amount of tannins as the next. This is a major pitfall of fuming and I’ll show you results of using woods from different sources, I was very disappointed recently when I pulled out a little arts and crafts cellarette to discover that the three panels in the door had changed colors in a dramatically different fashion. It is some extremely beautiful wood too but it’s different colors. Two panels are real dark and the middle one not so much. I have some before and after pics and pre fuming the woods were almost identical in color. So, watch out for that.
as far as I know it makes no difference as to fuming before or after but it does magnify any squeeze out so work as clean as you can. And watch out for sapwood as it doesn’t fume at all.
I get my ammonia from HiValley Chemicals ( I think that is the name)

Well I apparently I don’t have any post fuming pics on photobucket yet but The two outer panels are now much darker than the middle panel. I’ll try to upload some pics to show them. Try fuming, I think it’s easy and interesting and experiment with different woods. I discovered that cherry and mahogany also fume well.
Good luck

-- I was born at a very young age, as I grew up, I got older.

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