Originally Posted by christep

This is just wrong - as a OneWorld Emerald you have access to any OneWorld airline lounge (F or J) when flying on a OneWorld airline from that airport that day. I have never had any difficulty at all with this (except once with FinnAir in Helsinki, where they took some persuading). The only exception is for AA EXPs flying on "domestic" North American flights.

I notice though that your profile says AA Plat, which is OneWorld Sapphire, not Emerald. In this case you would be refused access to F lounges, but you would have access to J lounges (with the same exception for North American flights).