Instructables

Ammonia + Aluminum?

I was reading all of the labels on things in my house, mostly spray-able things like spray paint, spray adhesive, spray enamel, etc., etc., to see what's flammable, and on the bottle of ammonia we have it says "Do NOT use to soak aluminum utensils in...." or something like that. What does ammonia + aluminum equal or do? Is it flammable? Thanks all you chemistry-buffs!

nurdee12 years ago
I saw this on my bottle also. and guess what I had to try it. Nothing spectacular happens. I put some aluminum foil in a test tube and poored ammonia over it, the only thing that happened was that the aluminum darkens and little bubbles of gas are released. The gas is hydrogen. Unfortunately the build up is very slow and the reaction doesn't create much heat so there is no explosion. Bummer.
I am trying to remove an aluminum seatpost from a steel bicycle frame. A recommend method of getting the seized part unstuck is to put ammonia between the tube and the seatpost because it will dissolve the aluminum oxide. However the posts above seem to say that ammonia will cause aluminum to oxidize, which would only make matters worse. Can anyone shed light on whether putting ammonia in the tube would help me un-stick the seat post? Is there another method of de-oxidizing aluminum? Also, are there penetrating oils that would work on aluminum? I was informed that WD-40, Liquid Wrench, etc. will work on steel-steel rust but will not un-stick steel-aluminum rust.
soak the aluminum corrosion with brake fluid. automotive distributers corrode in cast iron blocks all the time and paoring brake fluid around them and letting it soak always works
me too. Trying to remove a frozen/corroded aluminium handlebar stem from a steel bike. I've twisted and sprayed and finally resorted to ammonia. Did you have any success roundaboutit?
I have the same problem and from a bit of Googling (stuck aluminum seat post) it appears that either ammonia or caustic soda (sodium hydroxide) should do the job. Caustic soda (NaOH) is probably more dangerous to you than household ammonia, it's the main ingredient in "Drano". To get it into the gap between seat post and frame it seems to be suggested to put the frame upside down, block the hole with a cork, and pour the ammonia or NaOH in thru the bottom bracket. Take care and use PPE (goggles, gloves, long sleeves etc.). And be patient!
omnibot4 years ago
OMFG I LOL'ed sooo hard at these comments. Piss and coke-cans .. thefuel of the future. Priceless. Here I go :
-Ha ha harr harr hir hirr ho ho ho moho mo ho  mo .. MOAH HA HA HAAAAA!!!!
I am trying to remove an aluminum seatpost from a steel bicycle frame. A recommend method of getting the seized part unstuck is to put ammonia between the tube and the seatpost because it will dissolve the aluminum oxide. However the posts above seem to say that ammonia will cause aluminum to oxidize, which would only make matters worse. Can anyone shed light on whether putting ammonia in the tube would help me un-stick the seat post? Is there another method of de-oxidizing aluminum? Also, are there penetrating oils that would work on aluminum? I was informed that WD-40, Liquid Wrench, etc. will work on steel-steel rust but will not un-stick steel-aluminum rust.
jasldflkjf5 years ago
try getting strips of Al and put it into a plastic soda bottle with aqueous ammonia and the bottle should burst given enough time
Bran (author) 7 years ago
Do y'all think that a Coke Can would be adequate for testing, as I don't really have much spare aluminum at the moment. :-P
Kiteman Bran7 years ago
The can is painted on the outside, and probably lacquered on the inside - try sanding the paint off and testing the exposed metal.
If I apply this at a larger scale, say several pieces of alminum cans and one liquid ounce of household ammonia, could this be an adiquate source of hydrogen to give my car better mpg?
Only if your car is already built to run on hydrogen, and even then it would be a stupidly expensive source of H2
Bran (author)  Kiteman7 years ago
Will do.
Bran (author)  Bran7 years ago
I cut the bottom and top off the can, then a straight line down the body so I would have a long strip. I sanded down the non-painted side (misread your post) and the bottom of the can. I bent the strip into a box type shape to keep the ammonia from spilling out. I poured some in, and waited a couple of minutes. It started bubbling (very tiny bubbles) which apparently is due to corrosion, then I poured the ammonia out. There was a line showing where the corrosion is. I'm pretty sure if I had let it sit there overnight the effects will be more significant. Heck, I'll try that.
IMG_0486.jpgIMG_0545.jpgIMG_0544.jpgIMG_0525.jpgIMG_0502.jpgIMG_0519.jpg
Kiteman Bran7 years ago
Hands-on science at it's best. The bubbles (see GiveItSomeThought's post) will have been hydrogen gas. Sounds like a new way to collect everybody's favourite fuel of the future. Shred old drink cans and mix with old pee - collect the gas and drive to work on it. All you need to do is figure out an environmentally-friendly way of retrieving the aluminium salts from solution. Maybe evaporate the water and sell them back to the smelters?
Ammonia is a gas, formula NH3, which boils at -28 degrees Farenheit. Household ammonia, as you are using, is made of this ammonia gas dissolved in water; household ammonia is also called aqueous ammonia, because of the water. Here's the funny thing: it's the aluminum that is reacting with the water, pulling oxygen out of it and liberating the hydrogen gas (highly flammable - talk to the Hindenburg blimp people). I don't know how, but the ammonia (to a small degree) is allowing the water to get past the protective aluminum oxide coating that lemonie talks about.
NASA approves of using ammonia, NH3, a great refrigerant, in their aluminum heat pipes. But they say, "trace amounts of water in ammonia can lead to a reaction with the aluminum container and the formation of hydrogen gas." This is where I learned it at: http://www.nasa.gov/offices/oce/llis/0698.html
bommber man6 years ago
try to see if you can conduct on different cans cause some of them use different types of chemicals try to read the ingrediant its proobly there is proboly the answer
Guppy86 years ago
actually, urine has extremely small traces of ammonia, but the comment was still very funny.
lemonie7 years ago
Aluminium is extremely reactive, one thing you learn in chemistry is that the only reason it doesn't spontaneously combust / turn to dust is that it that is rapidly acquires a coating of (protective oxide).
But basic solutions, including aqueous ammonia can get past this and corrode the metal (Kiteman). Exactly what this does I don't know, and can't be bothered to research, but I'd appreciate it if you shared the results of any home experimentation you do.

L
Kiteman7 years ago
Ammonia is corrosive to aluminium, so if you soak your aluminium cuttlery in it, you'll only do it once...