BB removal after loctite has been used

Discuss light weight issues concerning road bikes & parts.

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alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Great idea with that freeze spray. I say try it. 80 degrees on the shell and minus 30 on the cup could do the trick!

Another idea which is very hard to implement, unless you have a press, is to apply a good constant load to the cup and then with a focused flame just quickly heat the cup up to 200 degrees to try and melt the bond. I realise it will expand but the idea is to quickly break the bond without transferring heat into the carbon.

Carbon is a poor conductor of heat. Alloy is very good so if done in quick attempts could be helpful.

If all else fails...

/a

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fa63
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Location: Atlanta, GA, US

by fa63

I have no useful advice, but reading this made my appreciate my English threaded BB even more :)

Good luck!

Alexandrumarian
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Joined: Mon Mar 28, 2016 6:34 pm
Location: Romania

by Alexandrumarian

I glued my Campy cups to carbon with 648 which I think is tougher and more heat resistant than 609. Just happened I couldn't find 609 in a hurry. If I ever have to remove them I'll try the slit and pry/peel method.

mdeth1313
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Location: Dutchess County, NY

by mdeth1313

I corresponded with someone from park tool, as I had a BB that was installed with their primer/green retaining compound and their suggestion was to heat the cups with a hair dryer and then try to release. Trying to do this in a stand will be futile. The frame needs to be braced against something for the blows.
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toastie
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Joined: Sun Dec 20, 2015 11:55 pm

by toastie

I’ve just called loctite Technical and according to them there is no solvent available to soften or break it down! The only way to remove it is to heat it up and apply force.
Any one know what temperature a carbon frame can go to before it damages the resin?

Valbrona
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Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

Heating up cups is easy with an electric current. You connect the live wire from a household socket to the LH cup and the neutral wire to the RH.

And then if you are still alive, whack it with a hammer!

darnellrm
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Joined: Thu Sep 10, 2009 1:06 pm
Location: NC, USA

by darnellrm

Use a metal hammer instead of the "dead blow" hammer. These plastic hammers absorb much of the sharp impact needed to break the bond.

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Miller
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Location: Reading, UK

by Miller

When I started with press-fit I selected Loctite 641 as the literature says it is "designed for the bonding of cylindrical fitting parts, particularly where disassembly is required for servicing operations". I use it very sparingly, just a few drops, and haven't had any creaking issues (touch wood).

No current need for dissassembly but is 641 likely to make removing a press-fit cup easier than if 609 had been used?

alcatraz
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by alcatraz

If the frame is an open carbon shell it must be heavily reinforced around the cups. If you can support the frame just around the cup then the chance of damaging it is very small. (When you have an alloy insert the fear is that the insert comes loose as it's bonded to the carbon.)

The frame can take more force than you think, just support it well. Take precautions with the paintwork and take out your big hammer.

/a

sungod
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by sungod

Miller wrote:
Mon Jul 30, 2018 12:40 pm
...No current need for dissassembly but is 641 likely to make removing a press-fit cup easier than if 609 had been used?
yep, assuming otherwise identical usage, 641 is about 75% the shear strength of 609

it also weakens earlier when heated, by 100c it'll lose about 45% initial strength

joeyb1000
Posts: 376
Joined: Thu Mar 03, 2016 8:37 pm

by joeyb1000

I had a threaded Phil Wood BB that was stuck in a carbon frame because I used too much loctite. I held a soldering iron against the Phil Wood ring at various points to get it warm. That was enough to soften the loctite and get it out.

For your problem, I would make my own extractor. (1 1/2" PVC connector, a long bolt, something that would go behind the cup)

toastie
Posts: 70
Joined: Sun Dec 20, 2015 11:55 pm

by toastie

Right for anyone else that has this issue this is how I resolved it.

After talking to carbon composites which is a company that repair carbon frames they told me it was safe to heat the cups to 100c which should soften the loctite enough to remove the cups.
I used an electric heat gun to heat it up, a infra red thermometer to monitor the temp of the frame and an internal bearing puller connected to a slide hammer. It still took a decent amount of force to remove the cups but once they started moving they came out pretty easy so it’s all done and I’m having a well deserved beer!

Thanks to every one for all the help and advice, very much appreciated

hambini
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Location: Cologne, Germany

by hambini

Calnago wrote:
Sun Jul 29, 2018 9:06 pm
The blow is not to any carbon surface directly, it is directly to the cup and just to break the bond of the retaining compound. A little heat is fine prior to this so long as it’s not so much as to soften the resins in the carbon, or wreck the paint, but I think Loctite says a temp of 250 degrees Centigrade is what’s required to break the bond which would not be very safe for your frame or paint.
Out of curiosity, what tool would you recommend to remove a Campy Pressfit Ultratorque cup slowly that has been installed with retaining compound and that wouldn’t damage the external BB area paint in the process? The thing is, even if it is a slow removal the bond still needs to be broken so the force would have to slowly build up to enough force to initially break the bond. Build up, build up, build up (all the while slowly wanting to, and maybe succeeding at, pulling some carbon fibers with it)... then pop!... the bond breaks. It’s not like the force is a nice even pull from beginning to end as it would be if there was no retaining compound involved. I’m good with the quick and painless method, but to each his own. Some residual retaining compound on the shell can then be removed carefully with an Exacto knife or something. It’s pretty easy.

The press I use is one of these

https://www.hambini.com/bike-tools/hamb ... press.html

It's the same press that I've had for 15 years and pressed in countless bearings ranging from my bikes to those used on F35's. I have found the park Tools presses to be a bit weak.

With regards the heat, a quick call to Henkel/Loctite and they will advise you to warm the area before dissassembly and then acetone may soften the bond some more but might attack your paint.

Thanks
Hambini
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Calnago
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by Calnago

Yes, next time I need to remove some I will try the heat gun to get things all toasty before the “tap”, and I use that word lightly :) .

But Hambini, so how does your press actually remove the Campy Ultratorque cups? I don’t see how it’s going to be able to pull them from the BB shell.
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hambini
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Location: Cologne, Germany

by hambini

This is the basic principle

https://www.youtube.com/watch?v=zD0q_0T ... e=youtu.be

You just change the dimensions of the hook/puller and the sleeve as appropriate. Also replace the nut for a press handle. As I work in the Aero indsutry, I appreciate standardisation. especially when you are in the middle of nowhere and need to fix something. I make everything to ISO standards and standardize on an M12 thread so it's all interchangeable.
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