Treating rust inside the frame?

[OddJobGarage]

Hey all! Wondering if I should be worrying about the rust that I'm sure has built up inside the frame tubing. Is it something to be concerned with? Is there an easy way to treat it? Or should I just worry about external surfaces? I've started cleaning off the frame now.

 

[Davis]

I wouldn’t worry much.

 

[Augiedoggie]

I had concerns with frame cracks on a build once. Frame down tubes had cracks behind steering stem. Welded cracks and fabricated a stiffener and gusset and welded the shit out of them. Shoved as many 1/16 copper coated welding rods as I could fit in open end of down tube and filled frame tube with liquid fiberglass resin until it wouldn't take another drop. Still have it some 35 years later. Made it a bit heavier, but it sure as hell won't rust in there. Never cracked again

 

[massacre]

If the rust is bad inside the frame, it will show up when TIG welding. Random sparks for no reason even though the outside metal is clean.
Eastwood does make a spray can with a remote nozzle that can be dragged inside frame rails to coat the inside.
I've never used one on a minibike but i have used it on automotive frame rails with good results so far.

 

[kirk]

Use aviation "tube oil".

 

[Skipp]

Why not plug the hole with rubber stoppers and fill the frame with evaporust? If it’s that much of an issue?

 

[sparkwizard]

Melt candle wax, pour it in one end of the tube and pour it out the other end.