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Pinhole brazed dropout

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Pinhole brazed dropout

Old 12-11-20, 10:58 PM
  #1  
Gazoo4444
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Pinhole brazed dropout

I know I'm in the wrong section. Not a building questions but wanted ask

Have a steel chromed fork. Found a pinhole on the fork dropout. Was told its where the dropout is brazed on the fork.

Is that something normal you guys come across. Any issues with this or any issues that can arise in the future or is it just a regular thing?

Last edited by Gazoo4444; 12-12-20 at 07:03 AM.
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Old 12-12-20, 07:06 AM
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dsaul
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A picture would help, but you can't post pics until you have 10 posts. If the hole in the in the tube, near the dropout, its just a vent hole and it was put there on purpose. Depending on the type of dropout, there might be a vent hole cast into the dropout.
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Old 12-12-20, 09:46 AM
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No I see the vent hikes above the dropouts. This is right where the dropout meets the fork leg. Very tiny hole in the chrome
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Old 12-12-20, 10:51 AM
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unterhausen
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it's just a defect then. Happens. Probably some flux and then they didn't bother to go back and fix it.
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Old 12-12-20, 05:08 PM
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Doug Fattic 
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It is common when brazing steel dropouts into stays or blades that little pinholes appear in the brass. They are not a structural problem but rather just cosmetic. Ordinarily these are filled with spot putty when liquid painting but that doesn't work when they are chrome plated. Most of us experienced builders on this list know how to avoid pin holes and we can give advice if someone is interested but the OP was not asking that question but rather if it is a defect to worry about. It isn't.
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Old 12-12-20, 06:38 PM
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unterhausen
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If a newbie tries to post a picture, it goes into their gallery and we can rescue it if we know it's there.
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Old 12-12-20, 10:03 PM
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As Doug says, a pin hole is pretty common, not a deal killer and can be worked around. Another painter (not Doug) has told me that many frames he paints have pin holes of some sort. Andy
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Old 12-14-20, 06:52 AM
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Thanks you guys already answered my question but now that I can, I'll add the pic
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Old 12-14-20, 07:12 AM
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Ah ha, I see 2 kinds of holes in your picture. The perfectly round biggest one is a vent hole purposely drilled so that hot air can escape from inside the fork blade when it is being brazed. If a hole wasn't drilled then the expanding air inside the blade when it is heated up while brazing would push out the melting brazing material.

The 2nd little hole right between the blade and the dropout is a typical pinhole that happens when brazing. That is a cosmetic but not structural problem.
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