Advice on rust

[Peter_se 8]

I have found some rust on my Kitfox 2 that I am restoring, what are my options here

leave as is?

make a sleeve of a tube for reinforcement?

replace the tube?

 

[Peter_se 8]

Full-size red here

 

[TJay 1041]

That's a tough call.  Should all be replaced but does anybody? I bet not.

[1avidflyer 1983]

Maybe a middle ground would be to infill that area with .040" sheet.  That's not a bad idea even with no rust.  JImChuk

[Peter_se 8]

Maybe a middle ground would be to infill that area with .040" sheet.  That's not a bad idea even with no rust.  JImChuk

Good advice, would that be riveted and glued alu sheet or welded steel?

I wonder what the thickness on the lower tube is?

I guess if I leave it as is the risk is of bending the tube in case of an hard landing, but then again the rust is where the top tubes are triangulated.

 

[1avidflyer 1983]

I used .040" 4130 chrome moly steel sheet for the infills.  Tig welded in place.  Here is the Kitfox 4 I did since then.  Using Grove gear on the Kitfox, so didn't infill the seat truss.  I also widened the fuselage while I had it torn apart.  Extra 4" of room makes it nice for "regular sized" people.... JImChuk

[nlappos 413]

Those added webs make the strength of the assembly several times more than the tubing alone. As gusset plates, they take all the bending and are immensely stronger that the original, so any weakening due to rust pits is completely gone. 

Looks like you added maybe 1.5 lbs to the truss?

[1avidflyer 1983]

Not sure on the weight exactly, but I feel it was worth it.  Although I have yet to try it out.  Maybe in a month or so.  JImChuk