Spinnaker dimensions for stock H18

Over a 1 year ago I posted here looking for dimension info for a spinnaker to fit my stock 88' H18 with a comp tip. I had some suggestions about cutting down a used Tiger spin, and also to avoid the SX spin as it is too full.
I would still like to find usuable dimensions to build an H18 spin if possible. I'm not looking for the best racing sail, but a decent downwind spin.
Any help?.. or a way to calculate a size?.. or suggestions for a sail(maker) that wouldn't be too costly?
Thanks.

_________________
Chris
'88 H18SE Arís

Chris,
You can use a F18 spin on a standard 18 mast but the attachment point will be way up on the comptip. The other option is to run the pole very low. The issue is luff tightness, it needs to be tight. I have a solid standard mast that is rigged for spin but I'm not sure the comptip could take the force that high up. You won't know unless you try. According to the Hobie factory guys the tip can take it, they even say rivets won't pull out. I would recommend you speak to Chip at Whirlwind about a custom spin with shorter leach and luff, foot and draft can stay the same as the F18. I would hate to hear that you broke your comptip and tore your sail apart because you tried to run a spin.

Sailmakers are very reluctant to give out dimensions they regard the information as proprietary.

J

Mike, I recall your advice about using a F18 spin, and that may well be my only option. I certainly do not want to mount a tang any higher than what is already recommended for the comp tip. But I will reach out to Whirlwind and see what they have to say.

Jeremy, I realize no sailmaker is going to give away their bread & butter, but I thought a published document may be around.

I did find a couple formulas online for calculating a spinnaker's size, but cut shape still eludes me.
Time to rig the boat and take measurements.

_________________
Chris
'88 H18SE Arís