I have 1000:1 ratio of every ingredient compared to Iron chunk, having multiple alts and trying to nail perfect masterwork drains iron chunk at very fast rate. Salvaging an obscene amount of gear and doing the Legion does not help.
Do you also have the same situation as I? Where you haveover abundance of everything except Iron Chunk.
Do legions, this will solve all your iron chunk and rawhide issues. 900+ of each per legion event 
Everyone will just say salvage, this is not true, it will never be sustainable unless you don’t masterwork your gear. Its all about continue doing what you are doing, but do legions constantly till you have a nice 20k+ of them, then just do legions when you need to top it up.
I was like you until just a few days ago
Not anymore. Run hordes/Tormented Bosses for equipment and salvage. Do events. Do legions.