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BB facing....before or after paint?

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BB facing....before or after paint?

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Old 07-02-20, 11:04 AM
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BigPoser
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BB facing....before or after paint?

Which is better?

Thanks in advance.

Brandon Poser
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Old 07-02-20, 11:34 AM
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Yes, both. They are done for different reasons. Facing while building is for checking alignment. Facing after painting is to ensure that the BB sits square against the BB shell.
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Old 07-02-20, 12:03 PM
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Originally Posted by Cynikal
Yes, both. They are done for different reasons. Facing while building is for checking alignment. Facing after painting is to ensure that the BB sits square against the BB shell.
Wouldn't to be best to not face the BB a second time after paint until the bottom bracket to be used is selected? Phil Wood BBs for example do not touch the shell face so leaving it painted both looks better and protects against rust
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Old 07-02-20, 01:32 PM
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I would agree with that. That remaining paint would protect the surface. I've never used a Phil BB.
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Old 07-02-20, 02:21 PM
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Doug Fattic 
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One reason to face the side of the BB shell that the cup presses up against is to protect against the cup pushing away the paint as it screws in. It not only pushes the paint from the face of the shell but also on the body as well. This depends on how thick the paint is. Eventually what happens is that water is introduced onto the body of the shell where the paint has been pushed away next to the face and it begins to rust and become ugly down there. I don't use my BB shell facer but rather scrape away the paint with a sharp Exacto knife. If I do it right I leave a bit of the primer as protection to moisture.
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Old 07-02-20, 03:43 PM
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Originally Posted by Doug Fattic
One reason to face the side of the BB shell that the cup presses up against is to protect against the cup pushing away the paint as it screws in. It not only pushes the paint from the face of the shell but also on the body as well. This depends on how thick the paint is. Eventually what happens is that water is introduced onto the body of the shell where the paint has been pushed away next to the face and it begins to rust and become ugly down there. I don't use my BB shell facer but rather scrape away the paint with a sharp Exacto knife. If I do it right I leave a bit of the primer as protection to moisture.

I really like that. I think I'll do this as it totally makes sense. Thanks Doug!
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Old 07-02-20, 08:40 PM
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A fine file held flush against the face does much the same. But I will file face's corner with the shell's OD first to prevent a chip off of paint from traveling from the face and onto the shell's OD, Same with the head tube faces. Andy
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Old 07-03-20, 09:00 AM
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Originally Posted by Andrew R Stewart
A fine file held flush against the face does much the same. But I will file face's corner with the shell's OD first to prevent a chip off of paint from traveling from the face and onto the shell's OD, Same with the head tube faces. Andy
Thanks Andy! I was thinking about this as well.
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