As I have been incorporating the bill of materials in the Compressed Earth Block (/brick?) Press, its occurred to me a list of skills needed to build the machine may be useful to have (and for each machine we document; thus I have forked this out of the CEB-specific documentation thread).  It seems "no duh" that if welding equipment is listed among the tools to build the machine, that someone should know how to weld, but I've actually decided required skills should be listed before required tools on my theory that the most difficult things to acquire should be listed first, to help someone who downloaded the instruction document because they interested in building a machine determine if they have what they need to actually build it.  Its more difficult, I think, to learn to weld than it would be to buy welding equipment.