My boat is on the river Tamar where the lower reaches have lots of relatively safe sailing space and also enables me to motor home easily should I have problems. This gave me the opportunity to try out my new "creation" inspired, informed and encouraged by so many on this site. I have never ever made a sail, changed a mast or attempted anything as adventurous for my sailing pursuits before.
So the last couple of days I have had the chance to try out the 22m2 sail I have finished making and here are my initial observations on a messy 15 gusting 20 knots day.
The gibs are more cambered(14%), as advised by Paul, than the main sail (8%) and start to flap at about 50 degrees to wind. Arne's given me some ideas to reduce that so I will try that out once I have had the opportunity to try the sail in calmer conditions.The mainsail is still good to about 45 degrees but by the time I turn anything less than 40 is starting to collapse. Windward performance was around 4 knots at 50 degrees tailing to stalling completely by anything much less than 40.
Lee helm occurred if i stalled as you would expect.
On any reach other than close hauled if over sheeted led to wind helm, which given calculations and the very forward position of the mast, would suggest my centre of effort is further back than my sail plan would indicate. My initial thought is that the gibs are perhaps spilling more wind so causes the effective CE to move back around 2ft (600mm).
When wind helm took place I simply sheeted out and the boat accelerated noticeably.
I took Arne's advice and put telltales on the leech of all my main sails and I have just started to use them as my main indicator of sheeting angles.
Coming back up the river the following day found me facing some less favourable conditions with force 5 gusting 7 conditions. I was on a broad reach. I started by using only two panels. Performance was exceptional, travelling around 5 knots and generally behaving though wind helm started a couple of times in gusts, but was rapidly controlled in about 15 to 20 seconds by my autohelm. As I got further up the river and winds were around 15knots and gusting had decreased, I raised another 2 panels.. The boat handled well at one point touching 7.2knots.
I am hoping to try things in lighter winds as weather permits and will let you know how I get on.