Need advice on bottom bracket repair

On Fri, 13 Jan 2017 10:17:20 +1100, James
wrote:

On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

I had never come across CLR. How effective is it in removing heavy
lime deposit in pipes?
--
cheers,

John B.

On 13/01/17 12:50, John B. wrote:
On Fri, 13 Jan 2017 10:17:20 +1100, James
wrote:

On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

I had never come across CLR. How effective is it in removing heavy
lime deposit in pipes?


No idea, John.

--
JS

On Fri, 13 Jan 2017 14:17:20 +1100, James
wrote:

On 13/01/17 12:50, John B. wrote:
On Fri, 13 Jan 2017 10:17:20 +1100, James
wrote:

On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

I had never come across CLR. How effective is it in removing heavy
lime deposit in pipes?


No idea, John.

I wondered. I've got a house drain line that has white deposits that
reduce the water flow considerably. I tried about everything I could
think of to dissolve them and so far no success. I had hoped you were
suggesting a solution.

A previous house we owned, in the same area, had lime deposits in the
water pipes so severely that we finally had the house replumbed. I am
afraid something similar is happening here.
--
cheers,

John B.

https://en.m.wikipedia.org/wiki/Aluminium_oxide

Heat

Chemical prob is acid delivery to the Alo then removing the new dissolved compounds n replacing with more acid

On Thursday, January 12, 2017 at 5:50:24 PM UTC-8, John B. wrote:
On Fri, 13 Jan 2017 10:17:20 +1100, James
wrote:

On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

I had never come across CLR. How effective is it in removing heavy
lime deposit in pipes?
--
cheers,

John B.

You're not supposed to drink it John. There are other products which will clean out your pipes.

On Saturday, January 7, 2017 at 9:33:31 PM UTC-5, Theodore Heise wrote:
Hi all,

I have an early 1990s Rodriguez tandem with a rear bottom bracket
in serious need of overhaul. The cranks flop severely.

I've pulled the cranks and the lock ring on the left side, but the
adjustable cup won't come out. It turns about a quarter turn, but
then gets too stiff to turn further. It has no flats for a wrench
instead having holes for turning with a pin spanner--so I'm unable
to put a lot of force on it.

I've soaked it with WD40, but still no joy. Any advice for me?

--
Ted Heise Bloomington, IN, USA

Have you had any luck getting that cup off or looser?

Cheers

wrote in message
...
On Thursday, January 12, 2017 at 2:06:31 PM UTC-8, Benderthe.evilrobot
wrote:
wrote in message
...
On Thursday, January 12, 2017 at 1:33:30 PM UTC-8, Phil Lee wrote:
"Benderthe.evilrobot" considered
Wed, 11 Jan 2017 21:44:04 -0000 the perfect time to write:


"Phil Lee" wrote in message
.. .
Theodore Heise considered Tue, 10 Jan 2017
20:00:09
+0000 (UTC) the perfect time to write:

On Mon, 09 Jan 2017 22:20:13 -0800,
Jeff Liebermann wrote:
On Mon, 9 Jan 2017 22:24:41 -0000, "Benderthe.evilrobot"
wrote:

"Theodore Heise" wrote in message
...
On Sun, 08 Jan 2017 17:01:01 -0800,
Jeff Liebermann wrote:
On Sun, 08 Jan 2017 16:31:15 -0800, Jeff Liebermann

wrote:
(...)

Yet another untested idea...

Use an induction heater on the steel cup.
https://www.youtube.com/watch?v=MyZEaPQinO0
https://www.youtube.com/watch?v=YJElT9xK3bk
https://www.youtube.com/watch?v=uimEZKrVNO0
https://www.youtube.com/watch?v=3u1IBgefNDs [1]
http://www.theinductor.com
You'll need various size coils for different bolts, cups,
seat
posts,
etc. There are induction heater kits on eBay:
http://www.ebay.com/itm/1000W-ZVS-Low-Voltage-Induction-Heating-Board-Module-Flyback-Heater-Brass-Coil-/282317713643
The steel cup gets hot and not so much the rest of the
bicycle,
including the aluminum bottom bracket which sucks away much
of
the
heat. However, you can get the steel hot enough to melt the
aluminum,
so please use an IR thermometer to keep the temperatures
down.
Aluminum melts at 660C.

Yikes!

Is there a problem?

Maybe, maybe not. I read "induction heater" and just assumed it
would be pretty complex, and possibly dangerous (to me and/or
bike). Maybe I goofed by not reading the links.


An electric heat gun is safer than a blowtorch - but I think
you still have to be a bit careful.

The heavy duty paint strippers aren't too bad, but some heat
guns are designed for lighting solid fuel cooking ranges.

The problem with external heat generators is that the heat
affected zone is rather large and will surely creep into
undesirable areas, such as painted parts.

No painted parts, it's polished aluminum.


...With an induction
heater, you only heat the steel parts. Aluminum only gets hot
as far as what it conducts away from the steel.

If you happen to have an induction cooktop stove, you can
demonstrate how this works. Put a steel pot on top of the
induction heater, and only the steel will get hot. Put an
aluminum, glass, or copper pan on the stovetop, and they stay
cold. Toss a coin with stainless (magnetic stainless mostly
works, non-magnetic does not).

It's the same with using an induction heater on the bottom
bracket. The steel components get hot, while the aluminum
bottom bracket and frame do not.

I don't propose heating the cup to red hot:

http://www.hearth.com/talk/attachments/metal-color-temp-chart-png.100306/
which is why I suggested an IR thermometer be used to monitor
the temperature.

Too much complexity/equipment for me, but thanks for the thoughts.

I'm slightly surprised by the lack of reference so far (at least
that
I've seen) to the relative expansion rates of aluminium (the BB
shell
and the rest of the frame) and steel (the bearing cup).
As aluminium expands at a much greater rate than steel, simply
heating
the whole lot by any significant amount (say by pouring boiling
water
over it) should ease the grip of the shell on the cup.
I've done this exact thing on components of many different things,
ranging from fairly complex engines to assorted plumbing!

Boiling water frequently doesn't get the job done - and its
guaranteed
not
to if someone previously used thread-lock.

But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.

The problem with that is that the corrosion in question is probably
rust.
Working it back and forth wouldn't ruin the threads

Yes it will - rust debris is abrasive, it also clumps when you try to
unscrew the cup. Forcing it will at best grind out the thread, and maybe
jam
it solid.

BTW; Aluminium oxide is even more abrasive - some grinding wheels are
made
of it.

How thick would the aluminum oxide be on the surface of the threads? And
since the cup does move wouldn't that mean that the threads are free?

Free until the rust debris clumps and jams it solid.

On 1/10/2017 3:33 PM, Sir Ridesalot wrote:

On Saturday, January 7, 2017 at 9:33:31 PM UTC-5, Theodore Heise wrote:

Hi all,

I have an early 1990s Rodriguez tandem with a rear bottom bracket
in serious need of overhaul. The cranks flop severely.

I've pulled the cranks and the lock ring on the left side, but the
adjustable cup won't come out. It turns about a quarter turn, but
then gets too stiff to turn further. It has no flats for a wrench
instead having holes for turning with a pin spanner--so I'm unable
to put a lot of force on it.

I've soaked it with WD40, but still no joy. Any advice for me?

--
Ted Heise Bloomington, IN, USA


Sometimes a partially stuck (yours turns a bit) adjustable cup can be removed by:

Putting something firm like a large socket over the spindle so thatthe edges ofthe socket are against the cup and the spindle is not protruding beyond that socket. Then you give the socked a few good raps with a mallet. Often that'll break loose a lot of the corrosion in thethreads. If the cup still doesn't turn easily I'd put my pin spnaar in position and then add spacers until the spacers are just beyond the edge of the spindle and then put the bolt back into the spindle to hold the washers in place against the pin tool which in turn stops the pin tool from slipping. I can put a lot more pressure on the pin tool that way. Alternatively, after tapping the socket that you put over the spindle and agaist the adjustable cup you can lay the bike on its side with the adjustable cup up and put your favourite penetrating solution onto any threads that are outside the BB shell. the fluid then has a better chance of running into the threads inside the shell than it does if the bike is vertical.


Yeah, keeping the pin spanner tightly in place so you can whack it with
a mallet should work. And use a fixed pin spanner, not an adjustable one.



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

"James" wrote in message
news
On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

If its in an aluminium housing - aluminium reacts with both acids and bases.

With only steel involved, a rust dissolver might work, but you have to be
careful not to use a rust converter like phosphoric acid - it converts the
rust into iron phosphate. Its pretty much the metal equivalent of
polystyrene cement.

If you treat it with a corrosive chemical; you'd better hope it works there
and then - if you put it aside to struggle with it later; the corrosion will
advance much more rapidly than it had in the first place.

If you're really lucky; you can work in enough penetrating oil to mix the
rust debris into a semi fluid paste - its still highly abrasive, but
hopefully doesn't clump and strip the thread out and/or jam it solid.

You'll invariably find tight spots, giving the cup a couple of strikes with
a hammer usually flattens down the high spots and you should then be able to
turn it a bit further. Its tedious to keep getting it moving a little bit at
a time - but usually less work than stripping the whole bike down and
rebuilding on a new frame. Its a fine thread that's easily compacted with
rust debris, but if you catch it early there might only be a few tight
spots.

Recently; I've found a few BB cups that weren't particularly tight to start
with - a sloppy BB bearing was why the previous owner threw the bike away.

"John B." wrote in message
...
On Fri, 13 Jan 2017 10:17:20 +1100, James
wrote:

On 13/01/17 08:33, Phil Lee wrote:


But in this case, there is already movement in the cup - all that's
needed is a little extra space for the movement of the cup in the
bracket shell to allow the corrosion to be ground down a bit finer by
working the joint back and forth.


I wonder whether a couple of hours soaking in a solution of CLR (Calcium
Lime Rust household cleaner) would help?

I had never come across CLR. How effective is it in removing heavy
lime deposit in pipes?

There used to be a product called Fernox DS9 for de scaling water pipes and
boilers.

There's also Brickclean used in construction for removing cement splashes
from the brick face. It contains detergent, so foaming can be a problem.