Scrap Iron is not exactly the most common reagent. One that is very common is Ore. I believe you can use a tranmutate card to turn Ore into Scrap Iron. Very handy if you need Scrap Iron fast and have ridiculous amounts of Ore.
scrap iron is contrary to popular belief a huge problem in wizard 101, I totally concur that it's shouldn't take huge amounts of game play time to gather this resource, when it should be as others, that you gather as you go alone playing,
why is there so much conversation about it? if there is not a problem Hmm?
I have been finding lots of scrap iron in Wintertusk, especially in the steamy area before you enter Nordrilund. Also ore there. Keep changing realms and you should collect quite a bit of both, especially if you are not trying during peak hours.