coloredcoat
Well-Known Member
So this topic is something I would never have considered previously. I'm a traditional aircraft aficionado and I'm well acquainted with welding techniques and benefits from making traditional tubing and fabric aircraft with the right alloy: 4130 steel. However, due to some fortuitous turn of events, my 20+ year career in aviation transitioned to working in the chemical process industry. Since that time, I've learned a lot about another whole world of stainless steel alloys that really make the modern life function.
So why not use stainless instead of 4130 steel? I've had many of the same thoughts and misgivings I've heard some of you make on here, and I thought it was worthy of its own thread. I'd like this thread to be informative and exploratory as I'm always open to learning. Before you post "It can't be done because _____ _______!" please check your assumptions and sources. I'm going to hopefully surprise you with some details and practicalities you've never thought of. And the goal is to make your and my future aircraft structure better and safer.
My question has become a premise: Why not use modern stainless steel alloy seamless tubing to build our aircraft structures? Most of us would have just as easy access to GTAW as oxy-acetylene, and some prefer GTAW already. Corrosion is always a concern, and I'd rather eliminate it than inspect for, tear off fabric to find, and repair it. With the advent of the synthetic fabrics, our 4130 tubing is the weak link in the design. I actually have cotton fabric from the 1960's that will easily pass the punch test. It was removed because the structure underneath was corroded severely.
Without making this first post too much longer, let's just also mention that the original paradigm in aircraft welded structure was to tear off cotton and recover every 6-10 years. Hangars weren't common, butyrate dope wasn't very weather proof, and cotton rotted in sunlight and rain. Steel tubing got repaired and painted and benefitted from this relatively frequent major overhaul. I think we need a new paradigm, and I'm 99% certain I've found a good improvement. However, I'd like to know if there is anything I'm missing. Tell me what you think.
So why not use stainless instead of 4130 steel? I've had many of the same thoughts and misgivings I've heard some of you make on here, and I thought it was worthy of its own thread. I'd like this thread to be informative and exploratory as I'm always open to learning. Before you post "It can't be done because _____ _______!" please check your assumptions and sources. I'm going to hopefully surprise you with some details and practicalities you've never thought of. And the goal is to make your and my future aircraft structure better and safer.
My question has become a premise: Why not use modern stainless steel alloy seamless tubing to build our aircraft structures? Most of us would have just as easy access to GTAW as oxy-acetylene, and some prefer GTAW already. Corrosion is always a concern, and I'd rather eliminate it than inspect for, tear off fabric to find, and repair it. With the advent of the synthetic fabrics, our 4130 tubing is the weak link in the design. I actually have cotton fabric from the 1960's that will easily pass the punch test. It was removed because the structure underneath was corroded severely.
Without making this first post too much longer, let's just also mention that the original paradigm in aircraft welded structure was to tear off cotton and recover every 6-10 years. Hangars weren't common, butyrate dope wasn't very weather proof, and cotton rotted in sunlight and rain. Steel tubing got repaired and painted and benefitted from this relatively frequent major overhaul. I think we need a new paradigm, and I'm 99% certain I've found a good improvement. However, I'd like to know if there is anything I'm missing. Tell me what you think.
