5776 is an 'anaerobic cure' adhesive. For it to cure it requires (a) absence of air (oxygen in fact) and (b) the presence of metal. See here for details:
Thread Sealant | Thread Sealing | LOCTITE® - Henkel Adhesives North America
So, the reason your excess doesn't cure is that it is in contact with air. Clever stuff.
Indeed. I had assumed it would cure due to moisture in the air as many other products do. Far cleverer this way though - gives me a virtually instant seal yet overspill can be easily cleaned no matter how long it's left.
It's exactly the type of high tech solution I was hoping to find. Bit neater than the old fashioned way too haha!