Dissimilar metal points

[Tree top pilot 13]

My manual states to sand away any coatings on the wing spar doublers before attaching with Hysol adhesive. Question is that the aluminum is going to begin a corrosion process or is the epoxy going to have enough film tension to create a barrier when riveted ? Just wondering about this.

Edited 1 Mar 2012 by Tree top pilot

[birddog486 21]

If theres a coating of hysol on both parts when there glued up and rivited this should be a non issue. The hysol will keep them from reacting.

My manual states to sand away any coatings on the wing spar doublers before attaching with Hysol adhesive. Question is that the aluminum is going to begin a corrosion process or is the epoxy going to have enough film tension to create a barrier when riveted ? Just wondering about this.

[Tree top pilot 13]

OK Thanks for the reply. I am always trying to think ahead and have a structure that will last a while. A friend said that a good airframe is worth two or three low time engines....

[EDMO 1078]

My manual states to sand away any coatings on the wing spar doublers before attaching with Hysol adhesive. Question is that the aluminum is going to begin a corrosion process or is the epoxy going to have enough film tension to create a barrier when riveted ? Just wondering about this.

Use lots of Hysol - Some builders plug one end and slosh paint on inside of spars, after riveting. Micro balloons added to Hysol makes a thicker coating.

As long as there is no moisture, and Hysol seperation in the connection, there should be no corrosion

- never heard of anyone complaining about corrosion in spars.

Ed in MO

Edited 3 Mar 2012 by Ed In Missouri