tubing interior rust inhibitor

[Brock]

Back in the day, so I've read, the inside of tubes were treated with 'linseed oil' (is that right?).  So now that I'm joining the ranks of tube-joiner I started to wonder if and how one would go about making sure that these tubes don't get moisture from a pin hole and rust.  A plane I took a ride in once killed the owner two weeks later when the tubing around the wing strut attach came apart.  So for the future owner (hopefully a long time from now) I'm thinking of drilling a small hole and giving a healthy squirt of ACF-50 or something like that.  Search failed to find any discussion of this.

[okdonn]

I have two points to make -
1- it will add weight if you are trying to make a part 103 compliant aircraft.
2- I'm rebuilding a wrecked Woody's Pusher, and got a surprise when welding one of the lower tubes - massive fire front the oil in the tubes. I put it out with the shielding gas from the MIG rig. I had to raise that side of the fuselage and let the oil drain for several days, then went back and patched the larger hole that the oil fire created. Not fun.
However, there is no sign of interior rust anywhere!

[Brock]

Thanks Don, yes the fire thing was interesting.  In fact I was thinking that if I were to drill a tiny hole to spray in some ACF-50 (or other) then welding that hole shut might get interesting with contamination and flamibility.
Fortuneately I am not going to restrict this build to 103.  Gives me many options to build EAB.

[Chuck in Indiana]

I *think* I still have some oil specifically for that use. You can have it for shipping cost. You don't use much. I'll look for it.