Galvanic corrosion between aluminum and stainless used for the firewall

[Gerhard Rieger]

Hi to all, what did you do to prevent galvanic corrosion between the aluminum angle and the stainless firewall?

[Wyo Johnson]

Gerhard,

Galvanic corrosion happens between to different materials when touching and if an electrolyte (water, etc) is present. If you isolate them with a good paint, this should do the trick. This is a common practice on general aviation and large commercial. Same goes for carbon graphite and aluminum...sometimes you can find specs for it online

Andy

[alaskabearhawk]

Nothing...left it as is.

[svyolo]

I think the quantiity of aluminum in the boot cowl and wings makes the anode (aluminum) big enough to far outlive me. Galvanic corrosion is occurring, but at a slow enough rate that I time out before the boot cowl or wings. I am more worried about a situation where me, the wings, and the boot cowl all become un-airworthy simultaneously. If the size of the anode (aluminum) was much smaller, it would corrode away sooner.

You can use steel fasteners in aluminum, but not vice versa. Big cathode/little anode, and the little anode won't last very long. It seems like nobody else worries about it, so I guess I won't either. I thought about it myself a while back.