Alodine on 4130 Steel - Problem?
I thought I was being so careful and thinking ahead. I wanted to protect the fastener holes on the hinge brackets on the horizontal stabilizer from corrosion by applying Alodine on the bearing surface. I took the brackets, thinking they were aluminum, and immersed them in Alodine to cover the bearing surface. These brackets, at least on the RV-14, are powder coated.
It was later in my build I realized that the hinge brackets were made of 4130 steel and not aluminum. I suppose the powder coating should have been my clue.
Now I'm concerned I may have compromised the steel with the Alodine. I've heard some rumblings about embrittlement of the steel with exposure to Alodine. I know of hydrogen embrittlement of steel, but I don't know if this is related. Since this is a very critical part in that failure of the part = loss of the airplane I don't want to take any chances.
Does anybody know about this? Can someone point me to some information? I've tried a Google search and nothing comes up specifically about Alodine and steel.
I can deal with replacing the hinge brackets on the horizontal stabilizer right now since I haven't yet riveted the rear spar assembly into the skin. I planned to do that on Sunday. I'll have to drill the rivets out, but that's no big deal at this stage of the build.
RV-14A Kit#140433, N393AJ Reserved
Completed: Vertical Stab/Horizontal Stab
Working on: Empennage (Elevator)
Construction log - mykitlog.com/ajackson
Dues paid on 10 October 2018
Member of EAA Chapter 92
Pet peeve: "Lose" is the opposite of "find". "Loose" means "not tight".