I am experimenting with etching 1084 and 5160 in a 1:4 ferric chloride solution. What grit and type of abrasive do you use for removing oxides? How many times do you go through the process?

Im guessing your talking about pattern welded steel?? If so I hand sand to 600,  etch, then hit it with 1200.  Be sure and use a flat/hard black when doing the 1200, you just want to hit the very surface, and use light strokes.

Also before you start the hand sanding after etch, be sure and neatralize the FC,  i make a slurry of baking soda/water.