Bare in mind I don't know what that might be... 2x a week is plenty as it doesn't hit the CNS system that hard. I'll also assume it's gripper strength rather than muscle work/size so... look at what works for most bodyparts now and drop the volume a little. Or check my training dairy for another way to go.
I have a captains of crush 1 and 2, but I cannot close the number 2 fully, what kind of sets and reps should I be using to attain maximum hand strength, and also how many times weekly.
Bear in mind that I want to fit it in along with my weekly weight lifting routine.
Yep. Current British and European champ, author of a book on the subject yada yada.
I hear you are something of a grip specialist?