It depends how your going about putting him in the spawning tank and when you are adding the female. Everyone does it different, there isnt a right and wrong way (to some extent anyway) and also each male is different.
I have had 2 successful spawns out of 3.
My first one all the signs were there, huge nest, female full of eggs but the male just ripped her fins to shreds so I took her out and never tried them again.
My 2nd spawn my female had been in the tank with the male (same male as the first attempt) for 24 hours (in her bottle) and he still didn't build a nest. Once she was released he eventually started to build his nest and I had my first spawn. It was over 18 hours before they started to wrap.
My 3rd time, once my female was added in her bottle the male immediately started building his nest, when she was released 24 hours later they were wrapping within 10 minutes and finished within 1 hour.
every male is different, no time limit can be put on it. He may build it before the female is added he may not....