Painting

Updated 9/9/2017

Since the below update I've decided to not paint the plane myself...  I went to a presentation at Oshkosh in 2016 by a guru of homebuilt painting and it was pretty convincing not to do it yourself.  It's a lot of work (mostly prep, including building a paint box) and it consists of using lots of toxic stuff that I'd rather not deal with.  I'm going to let professionals paint it after I'm done and flying the plane.

Updated 5/19/2016

I've started to investigate painting the plane since I'm likely to paint it myself (and I'm an obsessive researcher...) and do it at my house before moving it to the airport.  For my research I've been perusing both Sonex and Zenith builders forums and blogs since they use the same aluminum as the Sling.  But, it seems that no matter what you're building it's going to be 3 steps: 3 P's: Prep, Prime, Paint. 

A good overview of aircraft painting can be found here (for the prep it talks about the more complicated toxic approach).

Another good overview is here (be sure to read Part 2 also).

And yet another good overview is here.

Prep
For the prep I've found that you can go a more traditional (and toxic) route with Alodine, etc. or you can try a non-toxic prep treatment like PreKote, which is used by the US Air Force, large aircraft manufacturers and others with excellent results.  It's sprayed on and worked into a lather using ScotchBrite pads (which serves to scuff up the surface at the same time).  This is done twice.

Prime/Paint
Well, there's no shortage of options here!  Right now I'm thinking about Loehle Aero Coatings since I've read good things about their product, including that it's high gloss and durable.  A more detailed description of their recommended steps is here.

Here's a detailed write-up on someone painting their RV with the Loehle process.

Another system I'm considering is Stewart Systems, who are well known for their non-toxic paint system.

But, still much to be investigated!

Much more to be added here, but this is a start.