Does anyone have details about the Galvanic Interaction between Aluminum and carbon fiber in a wet environment?

Depending on the degree to which carbon fibre matting is actually fibres and resin, carbon fibre parts electrically can be peculiar stuff. The individual fibre, length-ways, are quite good conductors, a few ohms per 10cm not unlike a pencil lead, but the points of contact between fibres are very hit and miss, sometimes creating pin-point hot spots or if the resin has got in the way, total isolation. It is not unknown, ahem, for a careless 'improvement' of a transmission antenna, by replacing a glass fibre part with a carbon fibre one in a high electric field, for some of the carbon fibre parts to be just fine while other seemingly identical parts   catch light with the induced currents.(oops!)
The sheet conductivity depends critically on the degree that the resin has been squeezed in, and I can believe on a 'plane, that the fibres will be woven, and the resin fraction will be controlled and pretty minimal, ,so making a more or less conductive sheet, especially at fixings where the part has been drilled or cut exposing the fibre ends..

Then the only question is where is carbon in the ionisation/cathodic series, and the answer seems to be "far way enough from aluminium to have problems" - After all the carbon / zinc cell works quite well with a carbon positive electrode. 

The fact the modern alkaline ones are inside out, so the carbon is the a cup for the rest of it,  and forms the body rather than a central rod, reduces the cell resistance no end compared to the ones of my childhood where the zinc was the body, and the current had to bunch up to reach the relatively high resistive carbon rod. They also leak less often than I remember  ;-)

Mike

Hello Mike:

Looks like using carbon fiber is a lot more complex than I thought.

Thanks for the additional information.

Peter Brooks

Palm Bay FL

Hello Mike:

Looks like using carbon fiber is a lot more complex than I thought.

Thanks for the additional information.

Peter Brooks

Palm Bay FL