Test Flight #2 of Q2 C-GMBK

May 17/16  Springbank Airport elevation 3960 ft using the 5000 foot runway.  After much calculating of weight and balance and reading of others who have had the similar problem I decided to test fly again with more weight in the aircraft.  My first flight was with 5 gallons of fuel in the header tank which is ahead of the instrument panel and only my personal weight of 160 pounds. This had me nose heavy flying on the forward edge of the "Centre of Gravity" envelope.  On this second flight I would have 5 gallons in the header tank and 2 gallons in the main fuselage tank, 58 pounds of sand in the passenger seat, 25 lbs. of lead in the baggage compartment and my weight of 160 pounds.  I took off with and initial one circuit to see if all was going well, it was and I climbed to 6000 feet for orbits off to the unused side of the airport.  I remained aloft for 55 minutes and found that I could not trim the aircraft for level flight and my pitch trim was always at maximum for nose up attitude.  Some constant aft pressure was still required on the stick but much less than previously.   I came around an landed a much better landing this time.  More calculating is required to identify this problem.