So today I started working on increasing the prebend. The mast originally had 12mm prebend but this reduced to approx 5mm meaning I have quite a soft forestay tension.. The problem with a soft luff is that the leach will be soft as well opening too easily in puffs and curbing accelerations ignoring the fact that the soft luff will curve putting too much draft in the sail. The challenge is to find out how much prebend is optimal. To little and the leach is too soft, to much and the leach will not open enough in wind and waves. All the advice seems to be about 15mm for the A rig which is what my target will be.
I don't have a pre bend device so I am working the mast with my hands and being very careful not to over stress the aluminium. How hard can it be? Actually not that bad. After several goes I increased the prebend to close to 15mm and the jib luff and leech has firmed up considerably. No to get the boat back on the water and see what it looks like.
The other thing i have to fix is the corrector weights. I am 17 gm overweight with the A and C rig and 7gms over with the B rig. The boat was 24gms overweight according to the measurers scales originally so I cut some of that by reducing the counter weights on the jib boom but still need to take 17gm out of the correctors and add 10 to the inside of the B rig.
The trouble with the correctors is I siliconed them into the hull so that will be a challenge getting them out or maybe grinding the lead out.