Hi all

I have 200+ feet 2" by 2" iron rod that is covered with thick and
sticky protecting agent. It feels more like syrup than grease. Last
time I cleaned the bars with a degresing agent and high pressure water
and after that I used an angle grinder. And I may do just the same
this time. But it got me interested: how do (large) machine shops
clean their iron before welding? My method seems a bit impractical

As it is difficult or impossible to clean the inside of the pipe I
have considered heating the pipe endings near the weld before the
actual welding. The idea is to burn any possible oils remaining inside
the pipe away. Is that a practical solution? I use GTAW/TIG I I
believe that using a low current would allow me to heat the pipes
sufficiently to burn any oily residue but not melt the pipe? Any
comments?

IW