Antifreeze to loosen stuck stem?

On Thu, 3 Aug 2017 07:11:40 -0700 (PDT), jbeattie
wrote:


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.

I don't think it will work. Did you look at the metal surface under a
magnifier after separation? I did that on an antenna structure, not a
bicycle. I found a mixture of white aluminum oxide and red iron oxide
rust. The aluminum oxide is quite hard and penetrated the surface of
the steel tubing. The rust is not quite so hard, but still harder
than aluminum. Both surfaces were severely pitted. The problem is
that these pits are full of this expanded mix, locking everything in
place[1]. The only ways you can break this loose is to either
dissolve the aluminum oxide or gouge the soft aluminum.

The way I separated the steel tube and aluminum antenna base was by
heating and letting the partial vacuum created while it cooled to suck
in some window cleaner decanted from my windshield wiper reservoir.
This was on a 6500 ft mountain top, so my available resources were
rather limited. It took 4 tries, but eventually worked. What I
guess(tm) was happening is that the heat expansion was crushing the
oxide mix and pushing the rust further into the aluminum. When the
assembly cooled, it left a small air gap, which allowed more fluid to
enter on the next cycle. Eventually, the combination of dissolving
the aluminum oxide and enlarging the gap allowed separation.

Maybe some of these might be usable:
https://www.theruststore.com/Rust-Remover-Comparison-Chart-W22.aspx
https://www.theruststore.com/Rust-Removers-C1.aspx


[1] When something oxidizes, it usually grows in volume. This is
what happens to steel rebar inside concrete when it rusts. The rebar
and rust expand, cracking the concrete. That's roughly what's
happening inside the bicycle tube and stem.

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

YAWL miss a basic point I scream abt.....

the inorganic ionic transfer compound is between 2 tubes n has length

how deliver ammonia ...fresh fluid has to circulate over the compound ....uneeda delivery system pump in pump out like dentist.

rinse.

impossible. trees forest square hole round peg

I like the induction idea .....cast around for an induction oven for AM

On Thursday, August 3, 2017 at 1:19:18 PM UTC-7, wrote:
YAWL miss a basic point I scream abt.....

the inorganic ionic transfer compound is between 2 tubes n has length

how deliver ammonia ...fresh fluid has to circulate over the compound ....uneeda delivery system pump in pump out like dentist.

rinse.

impossible. trees forest square hole round peg

I like the induction idea .....cast around for an induction oven for AM

You're thinking that a chemical reaction is what is necessary. That is only the case if penetration proves impossible.

wrote:

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.


It's mostly an issue of what to try first. I've figured out how to apply
force with minimal risk of damage, next step is deciding what lubricants
to try.

I'm a little skeptical of antifreeze because the chemistry of
antifreeze has changed a great deal with the advent of aluminum engines
and radiators. Before aluminum engines and radiators were commonplace,
antifreeze had to be carefully chosen to avoid damaging aluminum parts.
The antifreeze I have very specifically states it's safe for aluminum.
That would seem to bode ill for the problem at hand, unless somebody
offers a recent account. The only dated story I have is from the '80s.

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.

That's encouraging, what year car? Was the antifreeze rated for aluminum?

It's starting to look as if I'll try to live with the bike until the
fall and it's too cold to ride. There don't seem to be any reliable
approaches except replacing the fork. I'm not there yet..

Thanks for reading and replying,

bob prohaska

AMuzi wrote:

Understand that the basic problem here is that metal oxides
are bigger than metals.
I fully appreciate that fact....

Ammonia in theory might reduce the
oxide, leaving some space. In practice I've had limited
success but some people seem to prefer it.

That's encouraging, would you say a little more? What strength
of ammonia? How hot (or cold)? How much time? I'm retired, so
patience is my only limit.

A little reading suggests that weak alkalis like ammonia can
react with aluminum hydroxide to form soluble salts. That's a
step in the right direction.

Thanks!

bob prohaska

On 8/3/2017 6:58 PM, bob prohaska wrote:
AMuzi wrote:

Understand that the basic problem here is that metal oxides
are bigger than metals.
I fully appreciate that fact....

Ammonia in theory might reduce the
oxide, leaving some space. In practice I've had limited
success but some people seem to prefer it.

That's encouraging, would you say a little more? What strength
of ammonia? How hot (or cold)? How much time? I'm retired, so
patience is my only limit.

A little reading suggests that weak alkalis like ammonia can
react with aluminum hydroxide to form soluble salts. That's a
step in the right direction.

A quick web perusal shows our archives, Mr Brown, some
chemistry fora where the posts are mostly personal invective
and one kayak forum with general advice to throw out
aluminum paddles.

In theory ammonia should reduce the oxide but in practice
time and temperature seem to be big variables.


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

That is only the case if penetration proves POSSIBLE

On Thursday, August 3, 2017 at 4:01:02 PM UTC-7, bob prohaska wrote:
wrote:

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.


It's mostly an issue of what to try first. I've figured out how to apply
force with minimal risk of damage, next step is deciding what lubricants
to try.

I'm a little skeptical of antifreeze because the chemistry of
antifreeze has changed a great deal with the advent of aluminum engines
and radiators. Before aluminum engines and radiators were commonplace,
antifreeze had to be carefully chosen to avoid damaging aluminum parts.
The antifreeze I have very specifically states it's safe for aluminum.
That would seem to bode ill for the problem at hand, unless somebody
offers a recent account. The only dated story I have is from the '80s.

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.

That's encouraging, what year car? Was the antifreeze rated for aluminum?

It's starting to look as if I'll try to live with the bike until the
fall and it's too cold to ride. There don't seem to be any reliable
approaches except replacing the fork. I'm not there yet..

I'm driving the only thing I can afford - a 1999 Ford Taurus. Too bad it has all sorts of bugs in it that none of the other's have. But I would buy another in a second.

The coolant system was drained by the best mechanic in the area and Ford rated coolant installed so I assume that it was rated for aluminum. Tom Arnerich never uses anything but the best factory recommended stuff.

On Thursday, August 3, 2017 at 11:05:53 PM UTC-7, wrote:
That is only the case if penetration proves POSSIBLE

Ammonia has a lot less surface tension than water so what I would do is try to penetrate with the antifreeze and then follow up with ammonia. And I would NOT heat the ammonia since it is toxic.

Duh supply and resupply

Read down thersa pedia

https://www.google.com/search?q=corr...obile&ie=UTF-8

Not finding a more corrosive nh3 ..no ammonia plus so far