So I borescoped my Tailpost today…

[Lee Finstad]

As I’m converting this Colt to conventional gear, I decided to take a peek up the tailpost’s innards. There is some rust and light pitting as this is essentially the only exposed inside tube on the fuselage. As my archival research on this topic has suggested, I am intending to ream it out using a 3/4” reamer and then slide a 12” piece of .065 4130 tubing up from the bottom to be rosette and bottom welded to the original tube. Then install the bottom Tailwheel attach point bracket. I’m using a T3 shock spring from Alaska Airframes for the added shock absorption and less stress on the Tailpost. Am I missing anything? Should I try priming the inside of the tube for future corrosion protection?

 

[Steve Pierce]

Not sure it needs to be that thick of a wall thickness but sounds like a good plan to me. Wouldn't hurt to pour some primer in there and rotate it around.

 

[dgapilot]

As I’m converting this Colt to conventional gear, I decided to take a peek up the tailpost’s innards. There is some rust and light pitting as this is essentially the only exposed inside tube on the fuselage. As my archival research on this topic has suggested, I am intending to ream it out using a 3/4” reamer and then slide a 12” piece of .065 4130 tubing up from the bottom to be rosette and bottom welded to the original tube. Then install the bottom Tailwheel attach point bracket. I’m using a T3 shock spring from Alaska Airframes for the added shock absorption and less stress on the Tailpost. Am I missing anything? Should I try priming the inside of the tube for future corrosion protection?

Original tailpost is only .049. No need to go any larger wall thickness than the original, all it will do is increase weight. If you finish weld around the bottom of your sleeve you will be creating a space to capture moisture. I would stick with just rosette welds. The original tube has lasted 50+ years, putting the sleeve should give you another 50 years.

 

[Armstrong]

You are going to love that T3!