4794 is a good wax for tarts. I use that by itself or add CB at 25%. Either way, my tarts are very strong.
Because of shipping costs I can't buy KY's tart/votive blend but that is another very good one. Even the pillar/votive blend.
You shouldn't have to use more than 1 ounce per pound with the 4794. Maybe the Fo's you chose need more.