NO airlock activity?? PLEASE HELP?!?!

I took some advice from a fellow hombrewer who i am friends with. He hold me i could use the yeast cake from my imperial stout (11%) (3weeks primary) and pitch my wort for a sweet stout right over top of the yeast cake. I did this and nave not heard a single bubble yet. I don't know what to do. should I pitch more viable yeast or wait till tomorrow to see if anything changes? HELP!?!?!

How long has it been?

30minutes....my friend said my airlock should go crazy immediately after pitching my new Wort.

The lag phase takes longer than 30 mins. It isn't like a gun. If it were you would pull the trigger 24 hours before you wanted it to go off. Wait a day or two...

Im just nervous this is my first time pitching on a yeast cake.

i typically see action within 8-12 hours at 65+ degrees on a half-yeast cake. longer if i'm fermenting under 65. it isn't immediate.

ok im not going to worry until tomorrow. But if i don't see any activity tomorrow should i pitch a yeast with a starter or will a packet of safale 04 work?

Stir it up real good, that should do the trick. Typically when using yeast from a previous batch you want to plan accordingly. Your first beer was big. You should work your way up to big beers. I.E. brew OG 1.045, stepped up to 1.065, then to 1.075, etc. not exact science, but your yeast is still viable and gets to grow with each batch. If pitching on a cake you may also want to look into washing your yeast too. Also check your gravity. It could be as simple as a loose seal and pressure is not building up enough to give u airlock activity.

Wait at least 2 days before getting concerned. Or take a gravity reading. If it is lower than your OG, you have fermentation. I think that your friends timeline was extremely optimistic.

good news.... I see activity!!! that was a relief!!

You need to relax a bit there buddy.