Guild Wars 2

Hi all,
my question is about using the same sigil twice on weapons P/P (in my case sigil of strength).
Will I get 2×30 = 60% chance to get a stack of might on crit ?

thanks in advance

Actually, no, they stack multiplicatively.
You will get a better chance to proc, however (~51%).

Have a read
http://gaming.stackexchange.com/questions/96296/how-do-sigils-work-together

Thanks shouzama for ur reply and link,
51% is still nice to try (if I can afford paying 2 more sigils of strength).