No lawn specialist (you might ask over on that forum here) but it sounds to me like you need to be watering less frequently but for a longer period of time. Well-watered it shouldn't be drying out that quickly.

Depending on the temps and the exposure I'd water 2x a day - early morning and again mid-afternoon - for a good hour or more and do that until it showed good germination. Then cut it to 1x a day. That's what the lawn guy recommended to us when we re-seeded part of ours that was a full sun plot and 80 degree days.

Either way if it is drying out then I don't think you need to worry about over-watering it.

Dave