Most builders have had fit issues with weldments at some point. I had a fairly major one with my WD-814 windscreen support/roll bar. When I test fit it initially, it had the usual problems; the forward part of the triangular gussets were raised up a bit, and it didn't fit very well between the vertical tabs and the fuselage cockpit rails. If I snugged up one side, it left me with a 5/16" gap between the tab and the rail on the other side. That's quite a gap:
I checked for possible solutions here, but didn't find much info on the side-to-side issue, so I called Van's builder support. They said it was a common problem and that I should definitely spread the hoop slightly so that the tabs will fit the fuselage. We discussed various ways to do this. I had tried the "armstrong" method of holding one end down on a padded surface with my foot and pulling upward... but I knew right away my back wouldn't care much for that. So I did some thinking... and came up with this solution. I used my cherry picker; securing a chain around the base, wrapping tie-down straps around either side of the hoop and securing them to the base chain and lifting hook, and carefully extending the boom to stretch the hoop:
I would stretch it a bit, let it spring back, and check measurements:
Eventually, after a couple bending sessions and a couple test-fits, I got it to fit just right:
I was so happy with the result, I wanted to share it right away. Van's said that the triangulated braces would probably pull together with the canopy rails with the bolts tightened; if I do any tweaking to those, I'll also share it here.