Antifreeze to loosen stuck stem?

On Wed, 2 Aug 2017 17:55:21 -0000 (UTC), bob prohaska
wrote:

I'd be curious to know what ideas folks have for dealing with
this predicament. Obviously I can use destructive methods, but
other optiions are worth exploring first.

This topic appears in r.b.t. about once per year, usually in reference
to a stuck seat post in the seat tube. Search Google Groups for
"stuck seat post" in r.b.t.

As I recall, the usual recommendations are (in random order):
1. Custom milling cutter to "drill" out the aluminum stem.
2. Sodium hydroxide (lye or caustic soda) to attack just the
aluminum.
3. Refrigeration or liquid nitrogen. The aluminum stem will shrink
more than steel, which might open a gap between the steel tube and
aluminum step. Ideally, heat the steel, while cooling the aluminum.
4. Slide hammer to grip the lower end of the seat post. For this to
work on a stem, the stem will need to be cut off and the center shaft
be enlarged by drilling or reaming.
5. Attach a vibrating tool, such as an ultrasonic scaler or Sawzall,
to break loose or crumble the rust.
6. Induction heater. This will heat the steel, but leave the
aluminum cold. The steel expands, but the aluminum stays the same
diameter. This works, but will wreck the heat treating and paint on
the steel tubes. You might be able to get away with it if you
carefully monitor the steel tube temperature.
7. Impact wrench. Chop off the top of the stem. Use a file to
modify what's left of the stem, into a hex bolt head. Use impact
wrench to drive it with an impact socket. Hopefully, the repeated
impacts will cause the stem to spin in the head tube.
8. Drill out the center hole in the stem to the largest possible
diameter without hitting the steel head tube. Take a hack saw blade
and CAREFULLY saw some radial slots. You really only need two slots
but more will be better. Pick a likely section (between two slots)
and beat on it inward with a hammer and cold chisel until the section
breaks loose. Pry under the remaining sections and they should just
fall out.

My original list was longer, so there are some ideas I've forgotten.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Bike Topl needs a search for 'HONE'

Super memory Electro

I recall only 1 or 2 claims of value fir the damaged bicycle, posts begin

I found the XXXX in a dumpster

or I was given...poss as a joke.

Life us long n this BS doesn't improve conditions

AMuzi wrote:

In practice, since you haven't moved it with normal methods,
I only tried for about an hour, not much for problems of this
kind. Mostly I wanted to see if the puller and chain sling would
hold, and it does. If folks gave posititive reports on the
antifreeze trick I'd try that next. It looks like I'll be using
the standard heat and penetrating oil quench cycle. That'll take
a day or two at least. Fortunately there's no hurry.

I do wonder though, what is the ammonia method you mention?

we would cut the stem, drop the fork and extract the stump:
http://www.yellowjersey.org/stkromi2.jpg

Didn't the heat to melt the aluminum anneal the fork?

Thanks for posting,

bob prohaska

On 03/08/17 04:39, Jeff Liebermann wrote:
On Wed, 2 Aug 2017 17:55:21 -0000 (UTC), bob prohaska
wrote:

I'd be curious to know what ideas folks have for dealing with
this predicament. Obviously I can use destructive methods, but
other optiions are worth exploring first.

This topic appears in r.b.t. about once per year, usually in reference
to a stuck seat post in the seat tube. Search Google Groups for
"stuck seat post" in r.b.t.

As I recall, the usual recommendations are (in random order):
1. Custom milling cutter to "drill" out the aluminum stem.
2. Sodium hydroxide (lye or caustic soda) to attack just the
aluminum.
3. Refrigeration or liquid nitrogen. The aluminum stem will shrink
more than steel, which might open a gap between the steel tube and
aluminum step. Ideally, heat the steel, while cooling the aluminum.
4. Slide hammer to grip the lower end of the seat post. For this to
work on a stem, the stem will need to be cut off and the center shaft
be enlarged by drilling or reaming.
5. Attach a vibrating tool, such as an ultrasonic scaler or Sawzall,
to break loose or crumble the rust.
6. Induction heater. This will heat the steel, but leave the
aluminum cold. The steel expands, but the aluminum stays the same
diameter. This works, but will wreck the heat treating and paint on
the steel tubes. You might be able to get away with it if you
carefully monitor the steel tube temperature.
7. Impact wrench. Chop off the top of the stem. Use a file to
modify what's left of the stem, into a hex bolt head. Use impact
wrench to drive it with an impact socket. Hopefully, the repeated
impacts will cause the stem to spin in the head tube.
8. Drill out the center hole in the stem to the largest possible
diameter without hitting the steel head tube. Take a hack saw blade
and CAREFULLY saw some radial slots. You really only need two slots
but more will be better. Pick a likely section (between two slots)
and beat on it inward with a hammer and cold chisel until the section
breaks loose. Pry under the remaining sections and they should just
fall out.

My original list was longer, so there are some ideas I've forgotten.

Dynamite.

John B. wrote:
:On Wed, 02 Aug 2017 14:41:46 -0500, AMuzi wrote:

:
:The old British car manuals called engine coolant a "seeking
:fluid' in that it seeps where water will not so in theory
:they may have a point. I don't know if it would be an
:improvement over GM-Delco penetrant or ammonia.
:

:I remember my mother's car developed troubles and the mechanic
:diagnosed it as a leaking head gasket. When asked why the gasket had
:not leaked during the past summer he explained that "anti-freeze",
:ethylene-glycol in this case, would "find leaks that water couldn't".

Anti-freeze has a lower surface tension than plain water. So it can
indeed find leaks that water doesn't. Modern stuff is also loaded
with additives that further lower the surface tension, which improves
heat transfer.



--
sig 72

On Wednesday, August 2, 2017 at 10:59:30 AM UTC-7, bob prohaska wrote:
A local bike shop suggested using antifreeze as a penetrating
lubricant to free an aluminum stem stuck in a steel fork. I've
never heard of the method and wondered if anybody here has
experience with it.

The bike is an old Cannondale with the original steel fork. The
stem is Technomics, unmoved for far too many years. I've soaked
the stem in pentrating oil and also tried automatic transmission
fluid thinned with acetone, I have not yet tried heating it since
the only surface accessible is that of the stem. That will be
tried, but I'm not holding my breath:

I managed to get a gear puller on it from underneath, using a
loop of chain around the hips of the fork for purchase, which
worked quite well. Alas, tightening the puller and rapping on it
with a hammper hard enough to dent a 3/8" nut used as a cusion
under the puller screw yielded zero progress. The locking wedge
can't be removed (the bottom of the fork isn't bored full diameter)
so the puller bears on the wedge, which is free on the stem. That's
not ideal but there's no obvious alternative.

I'd be curious to know what ideas folks have for dealing with
this predicament. Obviously I can use destructive methods, but
other optiions are worth exploring first.


Thanks for reading, and any thoughts,

bob prohaska

You ask a question and get answers for non-related questions. That's the tech group alright.

What have you got to lose trying the antifreeze? You should have a can of it around for your car anyway unless you have an electric car.

When my car heater stopped working I discovered that the previous owner had put water in the cooling system with multiple metals in the cooling system.. Adding coolant and pressure blew what appeared to be pus out of the heater core and the heater became functional again.

On Wednesday, August 2, 2017 at 8:39:19 PM UTC-7, Jeff Liebermann wrote:
On Wed, 2 Aug 2017 17:55:21 -0000 (UTC), bob prohaska
wrote:

I'd be curious to know what ideas folks have for dealing with
this predicament. Obviously I can use destructive methods, but
other optiions are worth exploring first.

This topic appears in r.b.t. about once per year, usually in reference
to a stuck seat post in the seat tube. Search Google Groups for
"stuck seat post" in r.b.t.

As I recall, the usual recommendations are (in random order):
1. Custom milling cutter to "drill" out the aluminum stem.
2. Sodium hydroxide (lye or caustic soda) to attack just the
aluminum.
3. Refrigeration or liquid nitrogen. The aluminum stem will shrink
more than steel, which might open a gap between the steel tube and
aluminum step. Ideally, heat the steel, while cooling the aluminum.
4. Slide hammer to grip the lower end of the seat post. For this to
work on a stem, the stem will need to be cut off and the center shaft
be enlarged by drilling or reaming.
5. Attach a vibrating tool, such as an ultrasonic scaler or Sawzall,
to break loose or crumble the rust.
6. Induction heater. This will heat the steel, but leave the
aluminum cold. The steel expands, but the aluminum stays the same
diameter. This works, but will wreck the heat treating and paint on
the steel tubes. You might be able to get away with it if you
carefully monitor the steel tube temperature.
7. Impact wrench. Chop off the top of the stem. Use a file to
modify what's left of the stem, into a hex bolt head. Use impact
wrench to drive it with an impact socket. Hopefully, the repeated
impacts will cause the stem to spin in the head tube.
8. Drill out the center hole in the stem to the largest possible
diameter without hitting the steel head tube. Take a hack saw blade
and CAREFULLY saw some radial slots. You really only need two slots
but more will be better. Pick a likely section (between two slots)
and beat on it inward with a hammer and cold chisel until the section
breaks loose. Pry under the remaining sections and they should just
fall out.

My original list was longer, so there are some ideas I've forgotten.

Other options for a stuck stem:

1. Hack off stem. Buy new fork. I did that with my old Cannondale (with no stuck stem), but then again, I installed a super-dangerous CF fork (that never broke, and I gave it away.) In fact, if Bob had only had this problem a few years ago, I could have sent him the old steel OE fork used on Cannondale road bikes from '84-90-ish. One could even make the move to threadless.

As for removing stems, what about soaking in an appropriate solution (ammonia or penetrant or what have you) and then using a pipe with the same OD as the ID of the steerer and whacking from the bottom? Mine never stuck so bad I couldn't twist them out, but working from the bottom up seems like its do-able.

-- Jay Beattie.

On 8/3/2017 1:26 AM, bob prohaska wrote:
AMuzi wrote:

In practice, since you haven't moved it with normal methods,
I only tried for about an hour, not much for problems of this
kind. Mostly I wanted to see if the puller and chain sling would
hold, and it does. If folks gave posititive reports on the
antifreeze trick I'd try that next. It looks like I'll be using
the standard heat and penetrating oil quench cycle. That'll take
a day or two at least. Fortunately there's no hurry.

I do wonder though, what is the ammonia method you mention?

we would cut the stem, drop the fork and extract the stump:
http://www.yellowjersey.org/stkromi2.jpg

Didn't the heat to melt the aluminum anneal the fork?

Aluminum flows below the steel's temper limit. We use a
large oxy-propane head for this.

Understand that the basic problem here is that metal oxides
are bigger than metals. Ammonia in theory might reduce the
oxide, leaving some space. In practice I've had limited
success but some people seem to prefer it.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 8/3/2017 9:11 AM, jbeattie wrote:
On Wednesday, August 2, 2017 at 8:39:19 PM UTC-7, Jeff Liebermann wrote:
On Wed, 2 Aug 2017 17:55:21 -0000 (UTC), bob prohaska
wrote:

I'd be curious to know what ideas folks have for dealing with
this predicament. Obviously I can use destructive methods, but
other optiions are worth exploring first.

This topic appears in r.b.t. about once per year, usually in reference
to a stuck seat post in the seat tube. Search Google Groups for
"stuck seat post" in r.b.t.

As I recall, the usual recommendations are (in random order):
1. Custom milling cutter to "drill" out the aluminum stem.
2. Sodium hydroxide (lye or caustic soda) to attack just the
aluminum.
3. Refrigeration or liquid nitrogen. The aluminum stem will shrink
more than steel, which might open a gap between the steel tube and
aluminum step. Ideally, heat the steel, while cooling the aluminum.
4. Slide hammer to grip the lower end of the seat post. For this to
work on a stem, the stem will need to be cut off and the center shaft
be enlarged by drilling or reaming.
5. Attach a vibrating tool, such as an ultrasonic scaler or Sawzall,
to break loose or crumble the rust.
6. Induction heater. This will heat the steel, but leave the
aluminum cold. The steel expands, but the aluminum stays the same
diameter. This works, but will wreck the heat treating and paint on
the steel tubes. You might be able to get away with it if you
carefully monitor the steel tube temperature.
7. Impact wrench. Chop off the top of the stem. Use a file to
modify what's left of the stem, into a hex bolt head. Use impact
wrench to drive it with an impact socket. Hopefully, the repeated
impacts will cause the stem to spin in the head tube.
8. Drill out the center hole in the stem to the largest possible
diameter without hitting the steel head tube. Take a hack saw blade
and CAREFULLY saw some radial slots. You really only need two slots
but more will be better. Pick a likely section (between two slots)
and beat on it inward with a hammer and cold chisel until the section
breaks loose. Pry under the remaining sections and they should just
fall out.

My original list was longer, so there are some ideas I've forgotten.

Other options for a stuck stem:

1. Hack off stem. Buy new fork. I did that with my old Cannondale (with no stuck stem), but then again, I installed a super-dangerous CF fork (that never broke, and I gave it away.) In fact, if Bob had only had this problem a few years ago, I could have sent him the old steel OE fork used on Cannondale road bikes from '84-90-ish. One could even make the move to threadless.

As for removing stems, what about soaking in an appropriate solution (ammonia or penetrant or what have you) and then using a pipe with the same OD as the ID of the steerer and whacking from the bottom? Mine never stuck so bad I couldn't twist them out, but working from the bottom up seems like its do-able.

Not likely with a butted steering column and a wedge type stem.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971