I was mis-informed about fuming!!

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Forum topic by TheWoodsmith posted 08-09-2010 10:04 PM 21057 views 3 times favorited 23 replies Add to Favorites Watch
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108 posts in 2920 days

08-09-2010 10:04 PM

Topic tags/keywords: question oak finishing arts and crafts

So I work with white oak quite a bit but had yet to delve into fume finishing for the sheer fact that i didnt want to ruin a good piece by finishing it poorly. Because I was only mildly interested in trying this I did very little research other than finding out that you seal up the work with some ammonia. On my latest commison I decided to give it a go, I did the glue up for the top, and prepped it by scraping and then sealed it in an old refigerator with a dish of ammonia. I looked deeper into the technique and saw alot of people saying that it would not work with household ammonia or anything weaker than 26% but today when I opened up the fridge the board looked almost identical in shade to images of other boards post fume, pre-topcoat I’ve seen on the web. I expected little or no result after 12 hours with cheap, dollar store, lemon scented ammonia but it worked I’m kinda confused here, did i miss something or are these guys saying that I have to buy my ammonia from chemical supply warehouses and bluprint supply or pool supply stores full of ammonia?

-- I know its around here somewhere...

23 replies so far

View richgreer's profile


4541 posts in 3074 days

#1 posted 08-09-2010 11:40 PM

I had always heard that you needed a commercial grade ammonia. I also understand that handling this ammonia can be quite dangerous. You must wear a good quality gas mask.

What you say here is both interesting and encouraging. I could be a lot more excited about fuming if I did not have to handle commercial grade ammonia. I may experiment with this.

Perhaps part of the reason for your success is that you were using an air tight container. Most people whip up some kind of a tent with sheets of plastic that is not truly air tight.

I may experiment with this myself.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View Bill White's profile

Bill White

4931 posts in 3960 days

#2 posted 08-10-2010 01:12 AM

And don’t forget…....AMMONIA IS EXPLOSIVE when the mix w/ air is just right.


View Gene Howe's profile

Gene Howe

10479 posts in 3428 days

#3 posted 08-10-2010 02:44 AM

Didn’t one of Stickly’s plants blow up while fuming? I seem to recall that story when we visited his estate in NJ.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View huff's profile


2828 posts in 3285 days

#4 posted 08-10-2010 08:08 PM

I used regular household Ammonia when I fumed the quarter sawn white oak gun cabinet I built this past year. I experminted with some sample boards first to see if it would work. I took three pieces of white oak and put in a box with some ammonia. I took the first piece out after 12 hours and was really surprised how much it had changed. I took the second piece out after 24 hours and it was darker and left the 3rd piece in for 48 hours and it was even darker. I wasn’t sure how much time difference there would be doing a large piece in a large box versus the small samples, but I had three different shades to compare and thought I could use them to compare the final tone I wanted on the gun cabinet. I built a large box and used four containers with ammonia in them to surround the piece. Closed it up and left it 24 hours ( that was the sample I liked the best). When I checked it after 24 hours, it looked lighter then the sample I made, so I closed it back up and left it another 12 hours (36 Hours total). What a great
look!. There isn’t a stain out there that can duplicate that look!. And it was so even and uniform. I was very pleased with the final results. Note: Make sure you take any doors or drawers off the cabinet so the air can circulate totally around everything or you will end up with tan lines!. (where ever one board overlays another). I’ve never heard of household Ammonia blowing up with a housewife, so felt a little safer using it instead of the very strong commercial stuff, besides, I had no idea where to get that. I still used a lot of precautions while using it ( rubber gloves, no exposed skin and I wore a respirator while working with it, since I was working with it full strength and in an enclosed area). Good luck with your project and let us know how it turned out. I did quite a bit of reading up on it before I did mine and almost all the time they mentioned getting the very strong commercial type ammonia, so I’m not sure if they never tried using the weaker ammonia, or just wanted faster results, but the household ammonia worked for me. I’ve done a couple small items since then and they are much easier to work with. (just because it’s easier to find something to put them in).

-- John @

View Wolffarmer's profile


407 posts in 3238 days

#5 posted 08-10-2010 09:36 PM

I really do not see how ammonia can be explosive when released into the air by itself. I have been in/around several accidental releases and nobody was running around worrying about an explosive. Ammonia is an oxidizer. Just like the oxygen in the air. Ammonia will choke the living crap out of a person. A shot to your eyes will destroy your eyes if you don’t choke to death first. 26% aqueous is not to hard to handle. When you get a whif of the ammonia you will get out of the way real quick. I would not fear it, just have a fan at your back and nobody down wind for about 25-50 feet or so. Don’t spill it on you. It just smells like very good house hold ammonia cleaner. very good. Being in agriculture i have been around a lot of anhydrous ammonia and have gotten a good whif a few times ( the accidental releases was another story of storage tanks blowing relief valves or a transfer hose breaking )

That being said. It is real easy to make an explosive with 26% ammonia. I took chemistry in college back in the 60s. ( Randy smiles and lets it go at that )


-- That was not wormy wood when I started working on it.

View jtriggs's profile


180 posts in 3817 days

#6 posted 08-10-2010 10:13 PM

I fumed my Morris chair project and disagreed with the conventional wisdom of using the strong ammonia stuff. I went to my local Fleet & Farm store and bought a gallon of ammonia that was no more tan 15% ammonia and I think it might have only been 10%.

I tested some scrap oak pieces in a plastic garbage bag for different amounts of time and found that after about 5-6 hours my wood was almost black. I ended up fuming my entire chair and the ottoman for no more than 1 hour and 45 minutes and the color finished up beautifully with some polyurethane. The poly warmed up the brown color just enough to give it a beautiful golden hue.

The amazing thing about fuming is that I cut some of the scraps up that I had used for testing and found the fuming had gone into the oak at least an 1/8 of an inch on all sides and on the ends, where the pores were, the fuming went in at least a half an inch and up to 3/4” on stuff that had been in for 3-4 hours. Talk about a deep finish!

I recommend trying it but not worrying about the strong ammonia products. The bottle I bought cost less than $2. Take precautions, fans , goggles, etc., because this stuff will still water your eyes and make you cough.

-- Jon --Always remember, never live your life by a motto.

View TheWoodsmith's profile


108 posts in 2920 days

#7 posted 12-03-2010 04:22 PM

acetylene is explosive by itself…. i dont think ammonia is that unstable or they wouldn’t let you by it as a consumer without letting that be known.

-- I know its around here somewhere...

View poopiekat's profile


4355 posts in 3734 days

#8 posted 12-03-2010 04:32 PM

Still chuckling over the ‘Tan Lines’ comment! I suppose the weaker ammonia stuff available at the supermarket would give you a little more control over the end result. I’ve only seen it done one time, at a cabinet shop that was doing a bit of resto work on a church sanctuary that burned. The shop pulled some old duffer out of retirement to oversee the work. They just used some makeshift tent canopy of canvas, and the 25% concentration. The panels and parts were a knockout! Ive never done any fuming myself, but I’ve restored quite a few pieces of fumed golden oak, I could never understand why people would ruin them with paint.

-- Einstein: "The intuitive mind is a sacred gift, and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift." I'm Poopiekat!!

View Bill White's profile

Bill White

4931 posts in 3960 days

#9 posted 12-03-2010 04:56 PM

Ask the folks at the fire department in Shreveport, LA about amonia and explosions. They can tell ya about the commercial cold storage facility that exploded and burned due to an amonia leak. I think there was 1 fatality.


View Jonathan's profile


2608 posts in 3050 days

#10 posted 12-04-2010 05:00 AM

I’m glad I decided to read this thread as it gives me encouragement to try something new. I don’t have anything right this minute that I want to fume, but may at least try experimenting with some scraps now, using the “over the counter” strength ammonia.

I will still take precautions, but am more curious than ever to see this process in action.

I’m also curious to see what others have to say about using the weaker concentration.

-- Jonathan, Denver, CO "Constructive criticism is welcome and valued as it gives me new perspectives and helps me to advance as a woodworker."

View Mike Gager's profile

Mike Gager

665 posts in 3267 days

#11 posted 12-04-2010 05:51 AM

regular grocery store ammonia will work just fine, it just takes a lot longer

View MsDebbieP's profile


18615 posts in 4160 days

#12 posted 12-04-2010 01:02 PM

From Canada's Health & Safety Site

What are the fire and explosion dangers associated with Ammonia gas?

Ammonia is generally not considered a serious fire or explosion hazard because ammonia-air mixtures are difficult to ignite and a relatively high concentration of the gas is required. However, a large and intense energy source may cause ignition and/or an explosion, particularly in a confined space. The flammable/explosion concentration range has been reported in various sources to be 15 to 28%. The explosive range is broadened to 15 to 79% by mixing with other combustible gases, (such as hydrogen and oxygen), by higher temperatures and by pressures greater than atmospheric. The presence of oil or combustible materials increases the fire hazard and the presence of iron lowers the ignition temperature from 850 to 651 deg C. Ammonia decomposes into flammable hydrogen gas at about 450-500 deg C. Toxic and irritating nitrogen dioxide can form during burning in air. Containers or cylinders may rupture violently due to overpressurization, if exposed to fire or excessive heat for a sufficient period of time, releasing flammable and toxic gases. Explosions of air-ammonia mixtures have occurred in confined spaces.

Is Ammonia gas stable when exposed to air, moisture, or heat?

Ammonia is stable at normal temperatures. It decomposes into hydrogen and nitrogen at about 450-500 deg C. Decomposition will occur at lower temperatures in the presence of metals such as iron, nickel and zinc and, to a lesser extent, catalytic surfaces, such as porcelain and pumice. In the presence of catalysts, decomposition begins as low as 300 deg C and is complete at 500-600 deg C.

Are there any conditions to avoid when using Ammonia gas?

High temperatures, electric discharge, electric sparks, welding

-- ~ Debbie, Canada (

View Tim Dahn's profile

Tim Dahn

1567 posts in 3565 days

#13 posted 12-04-2010 01:26 PM

I was just talking with a fellow woodworker a few days ago about fuming. He does it quite often using the regular store bought ammonia and it works great just takes a little longer. One tip he had was to put a test stick of wood in the fume tent that is easily removed so you can check the progress. Also recommended using the non scented variety.

-- Good judgement comes from experience and experience comes from poor judgement.

View MsDebbieP's profile


18615 posts in 4160 days

#14 posted 12-04-2010 03:27 PM

glad it was helpful. :)

-- ~ Debbie, Canada (

View tnwood's profile


258 posts in 3086 days

#15 posted 12-04-2010 04:35 PM

The whole conversation about the explosive character of ammonia is academic. Ammonia (NH3) can be explosive in certain high concentrations in air. The household or commercial ammonia from the store is NH3 dissolved in water and is actually no longer ammonia gas except in a low concentration and is not explosive. The problem with commercial grade ammonia is the high concentration which is corrosive and irritating to the lungs, skin, eyes, nose, etc.

And yes, the low concentration household ammonia will work for fuming if you give it sufficient time. The issue is one of concentration of the gas over the piece in question.

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