Welcome to the eG Forums, a service of the eGullet Society for Culinary Arts & Letters. The Society is a 501(c)3 not-for-profit organization dedicated to the advancement of the culinary arts. These advertising-free forums are provided free of charge through donations from Society members. Anyone may read the forums, but to post you must create a free account.
@TicTacAdditional comments - the amounts of water, oranges, sugar seem about right. I use the overnight procedure and leave the seed bag in until the end, but none of that is critical in my view as the oranges have a lot of pectin to begin with. Adding lemon or lime to the mix won't make a difference for reaching the gelling point as oranges are already acidic enough on their own.
I am confident you will get there if you boil it at a high enough temperature. 
@TicTacAdditional comments - the amounts of water, oranges, sugar seem about right. I use the overnight procedure and leave the seed bag in until the end, but none of that is critical in my view as the oranges have a lot of pectin to begin with. Adding lemon or lime to the mix won't make a difference for reaching the jelling point as oranges are already acidic enough on their own.
I am confident you will get there if you boil it at a high enough temperature.
