Bicycle Mechanics - Chrome vs. Ammonia

Hello all. I have an old chrome Schwinn Voyageur 11.8 that has the stem stuck in it. I've wasted an entire can of PB Blaster trying to get it out, and have had no luck pounding the unscrewed stem bolt down with a rubber mallet. A friend recommended using some household ammonia, but I'm wondering if it will effect the chrome of the frame. Any suggestions?

No worries.

chrome plating will not dissolve in the cleaning.

Thanks! Also, should I dissolve the ammonia, or just pour a capful straight in?

http://www.sheldonbrown.com/brandt/stuck-stem.html

Just for the record,ammonia WILL eat chrome.....not instantly,but it will remove the chrome,the nickle and the copper.It actually attacks the nickle and copper and makes the chrome flake off.If you heat it up,it will take it off fast.

Coca-cola will eat chrome if you leave it long enough.

Thanks! Also, should I dissolve the ammonia, or just pour a capful straight in?
household ammonia should already be mixed with water.


Just for the record,ammonia WILL eat chrome.....not instantly,but it will remove the chrome,the nickle and the copper.It actually attacks the nickle and copper and makes the chrome flake off.If you heat it up,it will take it off fast.

Coca-cola will eat chrome if you leave it long enough.

it should be fine for the purpose of removing an aluminum part, because aluminum is higher up on the reactivity series in comparison to nickel.

kuje: A rubber mallet may not transmit enough energy to the bolt to break the wedge loose. Try giving it a good, solid blow with a steel hammer or, even better, a 2 pound hand sledge and make sure that the fork is firmly supported so that the power of the blow is directed into the stem bolt and wedge, not in moving the fork around. Repeated pounding will do no good if you don't hit it hard enough to break the wedge loose.

Update: The ammonia was useless and ended up stripping off the clear coat. I am considering sawing off the stem, as much as I don't want to.

kuje: A rubber mallet may not transmit enough energy to the bolt to break the wedge loose. Try giving it a good, solid blow with a steel hammer or, even better, a 2 pound hand sledge and make sure that the fork is firmly supported so that the power of the blow is directed into the stem bolt and wedge, not in moving the fork around. Repeated pounding will do no good if you don't hit it hard enough to break the wedge loose.This. A rubbet mallet will just make you tired.

Update: The ammonia was useless and ended up stripping off the clear coat. I am considering sawing off the stem, as much as I don't want to.

it's possible the stem has a steel expander.

I like a 10-lb mini hand-sledge for a task like this.