I am planning to put siderails on my gavanized boat trailer. If I use aluminum, does anyone know if I will have corrosion problems due to dissimilar metals?

I really don't know, but from chem 101 that I took sometime after Moses died, I suspect that the Zinc from the Galvi will go first. You know the pecking order I'm sure. You use zinc tabs to sacrifice and protect the aluminum of a motor or hull. Alum should go to heck before the iron in the steele frame......but I can't remember much about the periodic table, I spent too much time looking at the girls.

Check out the galvanic corosion table at

SSINA.com

It looks like you'll be o.k.

Thanks for the input the ssina table tells the whole story.