Here’s one issue that I hadn’t considered until it came up on a Zenith discussion group: Do I need to paint steel parts that no one will see, like push-pull tubes for flight controls? Surely bare steel will rust, but do I need to go to town on paint or powder coat, or will a simpler solution work?
I’m kind of science-y, so set up an experiment today. I cleaned up three pieces of hot-rolled welder’s stock, painted one with Rust-Oleum enamel, coated one with WD-40 Specialist Corrosion Inhibitor, and left the control piece untreated. They’re hanging on the fence, and we’ll to see over time how the different treatments hold up.
My money’s on WD-40. But no wagering, please.
(Update, March 24, 2022) So, six months down the road we have meaningful results: 1. The untreated piece has plenty of surface rust. 2. The enamel-painted looks nice. 3. The corrosion inhibitor-coated piece shows no signs of rust.
So far, I’m not seeing the need to paint steel parts no one will so, so long as they’re coated with corrosion inhibitor at each annual. But time will tell, the experiment continues!
The basics-of-machining class ended today, and I had a chance to do some work on a lathe. Renton Tech has a lot of equipment that dates back to its start as a training center for Boeing’s B-29 plant in Renton. The lathe I worked on was some of that gear.
I was learning how to handle a four-jaw chuck, which is kind of a pain. Nonetheless, I was able to get my work dialed in within a tolerance of a tenth, or .0001″. Not that I’m slick or anything, but that was 10 times more accurate than the work you would do with this lathe. It’s pretty amazing to see the degree of accuracy that is possible with tools from 80 years ago.
There’s been no new progress since completing the first take at a rudder and getting empennage parts delivered. Now that I’ve wrapped up machinist training it’s time to focus on nailing the checkride and making a few changes in the garage to make room for airplane stuff.
I present to you my initial work as a student of precision machining at Renton Technical College, in Renton, Wash. These are blocks of carbon steel and aluminum drilled to tolerances of no more than 30 thou. (That’s 0.030 inches.)
Eventually, this course leads to a program in Aerospace & Industrial Production Technologies — it’s a pipeline to Boeing, which of course builds 737s at a plant about two miles away from the college. It also gives me access to resources that will be useful as I build a Cruzer rudder and toy with the idea of building an airplane.