djkashuba 

I am working on a stuck stem. Hammering on the extended stem bolt has not worked. Soaking with tri-flo has not worked. Going to try ammonia and or PB Blaster.
Will ammonia or PB Blaster hurt paint if it spills over? I also have a head tube decal that I do not want to damage. Obviously going to try to be careful, but....

-D

roadrunner2012

The only ammonia that works is industrial strength ammonia (10%), and it will damage the paint.

Have you tried going in from the bottom of the fork, with the expander bolt removed? I've had luck using copper pipe to hammer the stem upwards. Also try to clamp the fork crown securely, and twist the bars/stem. If it moves a little, it will move a lot.

djkashuba 

The expander is stuck.The Stem will not move.

-D

roadrunner2012

Is it a good frame? Sometimes it's just not worth the effort. I have never not gotten one out, but sometimes the soak takes months. You are dealing with molecular bonds.

auchencrow

+1.
And these suggestions may work even better when used in combination with an agent like PB-Blaster.
(I've used PB Blaster quite a lot in the past and never experienced any issue with paint or decals, though YMMV, if your paint/decal behaves like chalk.)

Be advised that when dealing with a stuck stem or posts, you should hope for the best and expect the worst, because there are those times when even a hacksaw does not work.

auchencrow

Is the steerer tube bulged out at the expander?

djkashuba 

It is a GREAT frame. I will change my riding position before screwing it up. PB Blaster next then...

-D

djkashuba 

No.

-D

auchencrow

Then I would suggest heating the steerer tube to expand it ever so slightly below where the stem is, and continue beating down on the extended bolt, with the fork fully supported under the crown.

EDIT - If you haven't already tried PB-blaster - Try that FIRST!

roadrunner2012

The wedge or cone at the bottom of the stem should come out if you unscrew the bolt far enough. It may help a little if you tell us what type of stem and what the frame/fork is.

I've never had PB Blaster discolor paint, but 10% ammonia will. PB Blaster has limited effect on alumium/steel bonds. I have heard that Kroil will work, but have never tried it. Some folks have used ATF but I don't know if there is actually science behind the stories, or if they are anecdotal.

djkashuba 

The Stem is unmarked.
I have read that boiling water will break the bond between alum. and steel by expansion and contraction during heating and cooling. Seams that it would be hard on the head tube decal though.

-D


Ron Cooper by djk762, on Flickr


Ron Cooper by djk762, on Flickr

djkashuba 

Yes. First thing in the morning. I will try to keep it off of the paint.

Thanks for all of the replies.

-D

RubberLegs

Having had both stuck seat posts and stuck stems....Patience is called for....blast it with PB Blaster from above, tap it a few times, let it set for a day, flip it over, blast from other side...give it a few more good raps...let rest....repeat....took several days on one stem, working it a few times a day. Took a week on one stuck seat post. Alternating Hot water (near boiling) and ice water quenching may help....as metals expand and contract at different rates, it may help to break the bond

auchencrow

djkashuba -
If it's the head tube decal you are concerned about, how do you know that the steerer tube is not bulged at the expander?

Some yahoo could have over torqued it and that could explain why beating the bolt down hasn't freed it.

djkashuba 

OK I was thinking "Head Tube" when I read "Steerer Tube". The decal paranoia is regarding heat and chemicals coming into contact.

So pull the headset and check for a bulge?

-D

puchfinnland

I think if you can get the bolt out then thread it in from the bottom attached to a slide hammer, loosen the wedge off from the bottom.
I put a 2x4 in a vise and straddled the fork over it, just a little twisting of the bars left to right, nothing to extreme ,
i had a difficult tandem seat post that I got to twist just a millimeter, I then knew the battle was won.
that and some chemical persuasion, heating won't help, as the aluminum will just get tighter in the tube,
actually putting the frame in a walk in freezer might just do the trick, just be ready with the 2x4 as soon as it comes out.
hope it ends well!

auchencrow

Try the PB Blaster /ATF and clamping that fork crown to twist the bars as roadrunner said - but the expander wedge has to come out or that stem is staying put.

If all the less invasive methods fail - I'm afraid you'll have to sacrifice the stem - and possibly the steerer too if it is bulged.

djkashuba 

Thanks. That is the plan. Patience is one New Year's resolution.

-D

clasher

I'd guess that since the stem looks kinda low the expander could be inside the butted part of the steerer near the bottom. That is likely why hammering down doesn't work. The first thing I would do is take the wheel off and brace the frame upside and hammer it from beneath... I like the copper pipe idea mentioned upthread. I usually just thread another stem-bolt from the bottom and hammer on that.

I don't want to shill yet another product but since this is a pretty nice frame a safe product I've had some luck with is CRC freeze-off. Since we're trying to free aluminum from a steel pipe if we can get the aluminum to contract it might be possible to get it break free. Heating a stuck aluminum stem or seatpost is a terrible idea since it'll expand way faster than the surrounding steel. The freeze-off might do it... I've also noticed the dust-off cans will spray super-cold liquid if sprayed upside-down, maybe empty one of those on the stem and have a go at it.

There's always just cutting it off and getting out via chemical methods.

Ah crap so yeah the stem bolt is stuck too? Sorry I missed that... anyway I would drill the bolt-head out and take the stem out and then have a go at the expander and bolt with the fork in a vice. I reckon with some penetrating oil and 4lb sledge hammer I could get that expander out.

auchencrow

Normally I'd agree wholeheartedly with that, but since it's the expander we need to remove first, heat tends to break the chemical bond between steel (expander) and steel (steerer). (If the steerer is bulged however, all bets are off.)

Now if the stem is still stuck after you remove the wedge, then freezing or any of the other methods may work - but I have the feeling that the stem may just fall out if you can remove that expander wedge.

clasher

lol yeah I only caught that on my third re-reading of the tread... I have cobalt drills around so I'd be inclined to try drilling the stem bolt out before I heated anything up.

auchencrow

Hmmm - Cobalt. That might be the ticket.

sykerocker 

Definitely Patience. That is the operative word. I just freed up two PX-10 stems (a '73 and a '79) using PB Blaster. And we're talking a couple of dribbled applications per stem each day for a bit over three weeks. Now, for me, that's not a problem. I go into the shop, do an application, get working on the project of the day, whenever I take a break dribble in a bit more, then one last application before turning off the heat, chasing out the cats and shutting down the lights. I was well prepared to spend all winter in this process if necessary.

zandoval 

True but you have to love the challenge - Make it fun...

capella lugs

Having had both stuck seat posts and stuck stems....Patience is called for....blast it with PB Blaster from above, tap it a few times, let it set for a day, flip it over, blast from other side...give it a few more good raps...let rest....repeat....took several days on one stem, working it a few times a day. Took a week on one stuck seat post. Alternating Hot water (near boiling) and ice water quenching may help....as metals expand and contract at different rates, it may help to break the bond

I agree whole-heartedly with this poster - just keep trying , and give it time - Ive removed a frozen stem and seat post - and both took 2 or 3 weeks before there was any action - and after soaking with various concoctions (including diesel fuel) , and alternating hot water and freezing with CO2 - it finally moved - just a little - and as the other poster said - thats when I knew I had won - next day a little more movement and so on until it finally came out - but you really have to let the penetrating oil, diesel whatever alone to do their work - slow , but it can and does happen - good luck with it !