yes, you do need wordworking skill to synth this! i'm lvl 55 smithing and lvl 2 woodworking. I tried synthing one of these for fun and my crystal broke, I also got a +.2 raise to woodworking. I'm guessing you need around lvl 5-8 because ash lumber caps at lvl 8 woodworking. Can't actually believe i failed the synth lol oh well.
This is way way cheaper to buy on the AH so i suggest you do that.
Server: Diabolos
Character: Sabrecat
Jobs: 75WAR/37NIN/37THF/etc.