The thing I noticed is...~
Well I might be unlucky cuz in 5k ec using the spirit of the forge I got no chan on my venos gear.
I noticed I have some blood stones(The ones that you get from doing primal world quests and fsp,hdd,and whatnot),so i went to the Crogmagon forge that uses the blood stone thingies and I got -3 on sleeves for the first try.(You can hone the -3 to -5,-6).
A day after,I got -3 on chest,using the same forge.
I actually think that either I was lucky with the forge or there actually is a more chance of getting good stats with that forge.