Started the onerous task of filling and sanding the joint between the HS and the lower fuselage today. What makes this so hard is that it is only accessed from below. I was able to weight the plane nose down, with front strut compressed as far as it would go. This gave me reasonable access to the work, but I still had to stoop down and work above my head. My advice to others is to build up your arms and shoulders on more accessible areas first, before trying this job. I managed to get most of the right side done today, and should be able to move to the left side tomorrow.