Depends on the number of laminations you are using ,bows with veneers will use more, the more bows you make the more resourceful you become with that stuff. For a one piece bow I would start off with a heaping table spoon of each part in a clear disposable cup , I then chuck some scrap wood in a drill and blend it up real nice. Then make sure you butter each side of each lamination before putting them together.
Hope that answers you question a little .