matimeo

I have an aluminum seat post stuck in a chromoly frame and I am attempting to use the least invasive methods first for removing the post (I already hammered the seat crooked trying to break it free). I know that ammonia is supposed to loosen it right up, problem is I don't see any way how that ammonia is going to get down between seat post and seat tube to do the job. Is there a good way to apply ammonia in this particular case? I have used a spray bottle to get ammonia all over anything that might help but still no budging. I've done it several times and let it sit for some time and still no results. Can anybody enlighten me on HOW to use ammonia to get a seatpost off?

note: I realize there have been lots of threads on this subject, but none seem to adress how to apply the ammonia

well biked

Remove cranks and bottom bracket, put ammonia into the seat tube from the bottom side. I've never had to do it, I feel very lucky. I've always had success using your first approach, hammering the nose of the saddle. I actually have an old battered saddle I use for just such occasions-

edit: You'd need to make sure the top of the seatpost is plugged or stopped up some way to make this affective, of course, so the ammonia doesn't run out-

jbrians

take the seat off the post.
take the wheels off the frame
carry what's left over to your well secured bench vice and clamp the head of the post in the vice
using the frame as your lever rotate the frame around the post and when it breaks loose you can work it out.

The reality is that ammonia can clean out oxide but only if there is space for the ammonia to get to where it's needed.
I tried all of the suggested methods to remove one from a Kona frame I salvaged but only the brute force method worked.

AndrewP

Use duct tape to build a dam around the top of the seat tube.

day1si

I just had the same issue...
I ended up using Breakfree~CLP
That was after the forementioned didn't work. Although just pour it around the post...

matimeo

Has anybody ever actually removed the bottom bracket and poured ammonia into the seat tube?

matimeo

I assume this was with an aluminum post stuck in a steel bike?

peripatetic

Yes, the brute force method works--sometimes. When it doesn't, it doesn't, and no matter how many people tell you to do it, it still won't.

The areas that are stuck together really need to soak, for several days, in the ammonia. I've not had the time to do it with my two frames, but I've tried everything else (do a search in the C & V forum under my name, you'll find six or seven pages of detailed and helpful suggestions.)

So removal of the BB is certainly necessary, and then plugging one end. You might want to try using a foam stopper for lab equipment, or some other plug covered with some kind of silicon/plastic coating (make sure it won't get eaten by the ammonia). Then fill up the tube, so that the ammonia can slowly work its way down in between the seatpost and seattube.

Should this not work, a consultation of my aforementioned thread will show you the next alternative, which, thankfully, will require you to keep the plug in place. Then you use lye to eat away at the aluminum. My understanding is that this process also take several days. Should you wish to take this route, make sure you read up on the hazards of lye (NaOH), b/c it's very noxious to human flesh, organs, etc. Good luck, and report back with any success--I'm anxious to hear a positive story.

TimJ

So you haven't done the lye yet?

And re: the original and follow-up questions, I had a stuck stem (a little easier to deal with) and let it soak in ammonia for days and it didn't do anything. I also tried freezing the aluminum to get it to strink a bit. Freeze and unfreeze the whole fork thinking the seal might break with swelling, and also brute force which didn't work (I had enough leverage to completely ruin the stem's thick clamp and it never budged). I ended up having to melt it away with lye.

Couple things- don't use wd-40. I had a pretty-darn-stuck stem that would budge just a little with all my strength, so I did a test. I put some wd-40 in there to see what would happen and it made it worse. I put ammonia in there and it loosened right up.

Try the ammonia for a couple days then try getting some leverage on it and see if it will twist. If it won't then I would bet it simply will not come out without melting it out with lye. I don't know what it does chemically speaking, but in my case the stem and fork where seriously, chemically bonded together. Even when it was done melting out with the lye there was a sliver of aluminum still stuck in the steerer tube and it was stuck fast like it was lightly glued on. Good luck and hopefully you won't have to lye it.

KLW2

After you use ammonia or lye, be sure to rinse throughly with water (then vinegar if you use lye, to neutralize the lye) both are corrosive, especially lye which can dissolve aluminum and steel before your eyes.

TheMow

Ive never encountered this problem but why cant you put a propane or mapp gas torch on the post get it nice and hot then put a pipe wrench on the post and break it free. Spin it till it spins freely. Then it should slide right out

matimeo

Aluminum expands faster than steel- it would just make it more stuck.

TimJ

Lye doesn't do anything to steel. It will remove paint but it doesn't touch steel, or plastic.

froze

Do the Ammonia thing first by pouring down the frame when you remove the bottom bracket, and let it soak for several days; but do this outside in a garage so you don't kill everyone in your home with the odor.

In the future apply grease liberally (but do not apply grease to carbon fiber), this will not only prevent the corrosion but it will also prevent water from dripping down the seatpost and into the frame. I apply a thick dab of grease to the inside of the frame and spread it around the tube, and then apply some to the seatpost before insertion. Then just wipe off the excess that oozed out.

peripatetic

Nope. Had to move apts. Have no workplace for nasty chemicalsor rusty old frames. Still plan to do so, however.

drswift

The following worked for me. Al seatpost in steel frame. Pretty seized. Local bike shop tried and couldn't budge it.

Some of what I will describe goes against the advice here (Heating Aluminum), but it worked for me.

1. Got a handheld propane torch (~$25 from your local hardware store), a temperature gun to measure, and a two cans of compressed air from local dollar store.
   
2. Removed the seat.
   
3. Heated the seatpost up to about 500 deg (F), and a little bit of the top of the steel seat tube. Didn't really damage my paint much.
   
4. Then, turning the can of compressed air upside down, used it to freeze the seatpost, and top of seat tube.
   
5. I then whacked the top of the seatpost quite hard with a hammer, to drive it further into the frame, about half an inch, to break any "seal" of Al2O3. Add cutting oil (WD40) or ammonia while hammering the seatpost - this way the oil actually gets into your seattube...
   
6. Repeat steps 2 & 4, if needed.
   
7. It was a little loose now, for the first time I could twist the seatpost.
   
8. To get better leverage, and avoid breaking my seat - I just wrapped - very very tightly - a long hank of 850 Paracord around the seat post - yes this will grip aliminum, if you clean the seatpost first with alcohol. (Can sand your seatpost if you are desperate)
   
9. I then just tied a simple slipknot in the end of the paracord, and stuck a breaker bar in it, perpendicular to the seatpost, and that gave me plenty of leverage. (If you dont have a breaker bar, a simple metal-body hammer, or something else strong will do)
   
10. I was then able to turn the seatpost full revolutions, breaking the seal, then work the seatpost out using a bit of elbow grease...
    

TL;DR: Use a cheap form of heat and cooling to expand and contract the metals, and a bit of impact, to break the seal.

JanMM

Welcome to BF!

If you are responding to the original poster with the seized seatpost, then you are 13 years too late. (Maybe he will chime in with an update.)

If you are offering general advice to all who might need to remove a seized seatpost, then thanks!


Zombie Thread alert!

mixteup

If you decide to do the ammonia routine, if you have a commercial kitchen or cleaning supply place near you, you can get concentrated ammonia - It's sold to be diluted for cleaning stuff.
Think, nitro methane fuel vs. olive oil.

Good stuff, but DO NOT open it under your nose, in fact, don't even open it in the house ......

Loose Chain

Actually you are heat cycling. The aluminum does expand more and it also shrinks more. After heating, I then rapid cool the aluminum by using ice/dry ice (in a rag) and repeat. During the cycles I do tap on the post.

Racing Dan

If its not too deep in the frame, an other method is to saw it off at the collar, then take a hacksaw blade and gently saw it through lenghtwise from the inside. You can then "collapse" it enought to pull it out. Takes some patience, but unlike some og the usual "spray it with penetrating oil" ect. it does actually work.

scottz123

I had Alum Post stuck in Carbon Frame. I tried the Amonia, Coca- Cola, Kroil Penetrating Oil, etc. Spent hours messing around.

I "was" trying to save the seatpost.

Ended up having to cut seap post with 1" exposed above the frame - "hoping" I could use an adjustable reamer. Post was a lightweight model, with the ID oval (thicker in front & Rear, narrower on sides).

I ended cutting with a fresh hacksaw blade with a holder. I am fairly mechanically inclined, the narrow sides of post made it easier, and took maybe 30min not wanting to cut into the carbon frame. I only had to cut one side, the tube curled into itself with the hacksaw blade kind of binding up.

fietsbob

FAQ; So? have you looked in the forum archives to research
posts about this issue, from past ?






....

matimeo

Hi fietsbob,
You're about 13 years too late on this one. I had searched the forums, but that was back in 2006 when I posed this question.

I tried and tried with the ammonia and never could get it unstuck. I ended up paying the bike shop to drill it out.

fietsbob

yea Pyrrhic bargains abound out there ..

dumping a badly cared for bike to be someone else's problem ...

you are in the club...

fraba

So funny
Good you saved the bike. It's almost a C&V now!

No worries fietsbob, I almost did the same