by mike.smith » Mon Apr 25, 2022 10:00 pm
Like everything dealing with corrosion, it depends on lots of factors. Near the ocean, that's a huge factor in lobbying for excellent protection. Inland outside of Boston, in typical snow, rain and sun, my polished Sonex with stainless steel rivets has zero corrosion anywhere. Not even a hint. I had the plane outdoors with a canopy cover for 5 years, and no corrosion on the skins.
And I take a solid 2 weeks to do my annual condition inspection, including borescope inspections in hard to access places, so I'm pretty confident in that statement. In the Arizona desert, also probably not a big issue either. In a wet, tropical environment, probably a good idea to protect everything the best you can.
Since I didn't deem in necessary in my environment, I chose to save the weight. Because yes, corrosion protection does add weight, and my VW is weight-challenged as it is.
I'm about to start building an RV-7. Vans notes they don't believe corrosion protection is necessary unless you're in one of those particularly corrosive environments, so I'm choosing to simplify and save weight by not adding protective finishes inside. This plane, unlike the Sonex, will definitely be painted on the outside, however.