Typically I’d give my black base 30 minutes. One medium wet coat of 2K, let it flash for 10-15 mins, then a second wet coat. Let that cure overnight, then I’d chrome it. The chrome dries super quickly, it only needs a few minutes. Buff it well with a soft cloth, and then do the final seal with 2K.
One thing I will say, and I don’t always do this, if you can give the base 2K longer to cure (3-5 days) you will get a *slightly* clearer chrome. It’s not a huge difference, but it is noticeable. I only do it in special situations. If I’m just doing a “Beskar” Mando helmet for example, you don’t need that extra waiting time. It can actually make the helmet too shiny.
A few tips. Using an actual black base coat paint (as opposed to black primer) will give you a deeper black, which will in turn give you a better chrome. I use Omni Automotive paint. Second tip, some folks like to use a water based barrier (such as Alclad, UVLS gloss etc) between the chrome and final 2K clear layer. I like to seal directly with 2K, but if you find your chrome is being dulled down a lot, you can try the water based barrier as insurance. Lastly, make sure you really buff the chrome well before sealing. With Alumaluster at least I am not gentle at all. Anything that is loose will float up into your clear and kill the chrome.
Hope all this helps.