Originally Posted by themicah
The airside lockers in the terminal are very easy to find, come in a variety of sizes, and you can even use a credit card so you don't need coins or anything.
Excellent news - airside lockers! No need to re-scan my carry on when I return to AMS later on. Thanks for the tip!
(PS - I kinda figured there were no 'secure' lockers in the lounges, but never hurts to ask, right?)