Originally Posted by
BigO
Thanks for the input, guys.
I'd already decided to limit any corrosion protection to mating surfaces. I too believe that protection on the entire internals is overkill with AL; however, if on the slight chance that the plane got left in the rain or someting (especially unforseen) and water seeped into some mating surfaces, then galvanic corrosion could become an issue. The small amount applied to the mating surfaces is a good middle ground, in my opinion.
That being said, I have now used POR15 on my rudder kit, and I agree that it is too heavy. My research has indicated that protection applied on mating surfaces should add ~7 to the aircraft's weight; This stuff added somewhere around .75 lbs just on the rudder; I con only imagine how much more it would add over the entire airframe. I'll use it for completing my rudder, but I'll be switching to something else for the remainder of the project.
On a side note, I checked out your kit log, CarlOrton. That looks like I very nice Sonex you've built there. I wouldn't mind meeting over a cup off coffee if you'd be willing to impart some knowledge to a local, novice homebuilder.