# Glue for carbon fiber to aluminum



## nekkrush (Jul 8, 2008)

Builders, I have a carbon fiber seatpost that came loose from its aluminum seat post mount. Can anybody give me an idea of what glue I should use and how to prep either piece? -They fit together snuggly and there are no cracks in the Carbon fiber. Thanks!


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## PeopleForScience (May 15, 2012)

Any two part epoxy should hold for a little while. Aluminum and carbon are difficult to get a more permanent bond unless you wrap a layer of fiber glass between them to isolate the two materials.


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## nekkrush (Jul 8, 2008)

Thanks PeopleFor Science. What two part epoxy would you recommend that I could get at my local hardware store? I can figure it out, but feel like a beginner trying to buy bike lube and have no idea what I'm looking for.


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## PeopleForScience (May 15, 2012)

I typically use the loctite brand waterproof 2 part epoxy for home repairs. I've had really good luck with steel and carbon using that and okay results with aluminum and carbon. You can get it at home depot for really cheap. When I really want to stick things together I use west systems 205 hardener with the 405 resin. I also typically use some of the west systems fiber hardener. It is a powder that gets mixed into the two part and thickens it up quite a bit. The west systems products are great but in a totally different ball park as far as cost. 

If you want a long lasting repair then you need to find a way to isolate the AL from the carbon. I believe its called electrolysis. As I understand it (I'm no chemist) the AL corrodes and the carbon does not. That leads to the bond failing. You can use a layer of fiberglass between the AL and carbon. Also, some epoxies are a good insulator.


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## Fleas (Jan 19, 2006)

If the clearances are tight, you may want to go with some low-viscosity epoxy; something that works in tiny cracks. If you can sand blast the aluminum to create more surface area, you'll get a better bond. If there is a primer for the epoxy, that will do what PeopleForScience is recommending as far as isolating the materials.

You might check the local golf pro shop. They glue club heads on carbon shafts all day long. You might even find a little single-use pouch of the ideal adhesive.

-F


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## nekkrush (Jul 8, 2008)

Lots of ways to glue your seat back together and going w the two part lock tight. I'll let you know how it goes. Thanks for all the great info!


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## Feldybikes (Feb 17, 2004)

Dude, just chuck the seatpost and get a new one. Or better yet, a Thomson.

(I know this is in the grand internet tradition of not answering someone's question, but as someone who's witnessed a broken seatpost resulting in a torn scrotum [seriously] I felt compelled)


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