no need,, it will be a fairly superficial layer of rust ( oxidation from air trapped in the tubes ) this is fairly common in all box section / tubular structural constructions............ that is why many things are made from angle rather than enclosed section
I have just cut my 1983 Kawasaki frame to pieces and there was no rust on the internal pipes at all... so I would imagine the rust came soon after the accident... or the frame tubes were already a little rusty on the inside prior to welding - they won't oil the inside for storage in the factory and certainly won't have stock rotation in Italy. I know someone who ordered an 1199 and a Paso turned up! :Happy:
He was joking - the plugs do not plug the frame internals from the outside - the frame is sealed to the air apart from the cross tubes where the plugs go
the rust has certainly not formed post accident as you will notice the break is still clean .. interesting about the Kwak frame as any treatment pre manufacture will be burned off when welding,, unless they are oiled / treated post manuf
Good spot - so everyone - all your frames are like this on the inside - ride with confidence :Wideyed: Anyone else chopped a frame and found this when modifying?