Preparing scraps to weld on

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I got a bunch of steel from a local metal junkyard, some angles etc, its all rusty so my question is what should i use to clean it up so I can practice welding on it? just get out the ole grinder or?
Reply:What process are you using? If GMAW or GTAW, then yes clean it up a bit with a grinder. If SMAW of FCAW, you really don't need to unless you want to see what you're welding and where. John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Since you are practicing clean all metal, regardless of process. Eliminate as many variables as possible when practicing.A grinder  is good.  If you have the resources, then a muratic acid solution works quickly.  Dipping metal in a drum/bucket will allow you to clean several pieces of metal at once.
Reply:Even with SMAW and FCAW you want it as clean as possible.  It is good practice and you will get inclusions even with all that flux boiling out impurities.A wire wheel works most of the time for me.  And what won't come off with the wire wheel will come off with a grinder.  And in the case of grease/oil then use some acetone.
Reply:A good welder starts out being a good grinder...lol
Reply:I just did a little project using some reclaimed angle iron.  It had a nice thin coat of rust on most of it.  There was one side (the side that rested on the dirt outside the shop) that was particularly crusty.  A knotted wire-wheel removed the surface rust, and then a a pass with a flap-disk was used in the areas welds would be.  I cleaned up about 20', and it didn't take long at all.  After the welding was done (GMAW .030" ER70-S6 shielded with co2), a pass with the wire wheel over the welds, a wipe down with acetone and a coat of wrinkle paint finished it off. cricman