Sail & Mast questions

[Jeff]

This question arrived via email: "A couple very elementary sail and mast questions:
I see sail patterns from Bolger for a spritsail that have horizontal panels, but you advise using vertical panels, what is difference between the two orientations and why one over the other?

I know it’s a guide, not a rule, but, I have a 10’ tender I plan to add a sail to, the recommendation (generally) is to have a 12’ mast, but the luff of several spritsail patterns is closer to 7’, leading me to think a 7-8’ mast was adequate for a boat this size, is it because the peak extends above the luff that is why a 12’ mast be more within “range”?

Am very inexperienced, so I can only learn more as I ask questions." Jeff

[mhd]

This question arrived via email: "A couple very elementary sail and mast questions:
I see sail patterns from Bolger for a spritsail that have horizontal panels, but you advise using vertical panels, what is difference between the two orientations and why one over the other?

I know it’s a guide, not a rule, but, I have a 10’ tender I plan to add a sail to, the recommendation (generally) is to have a 12’ mast, but the luff of several spritsail patterns is closer to 7’, leading me to think a 7-8’ mast was adequate for a boat this size, is it because the peak extends above the luff that is why a 12’ mast be more within “range”?

Am very inexperienced, so I can only learn more as I ask questions." Jeff

I'm guessing this is the recommendation being talked about:

https://boatbuildercentral.com/support- ... it-rig.pdf

"For larger sprit sails, we show a reef line on our sail plans. BTW, despite what some of our drawings show, a sprit sail should be cut with vertical panels."

I had a look in "100 small boat rigs" by Bolger. On "Rig 25: Spritsail with Sprit Boom" he states "93 sq ft is set on a mast 12 feet long wtih a 13 foot sprit". To my mind that is a lot (too much!) for a 10' tender and I think you could get away with a shorter mast (~8') which would still provide ~60 sq ft of sail depending on height of sprit.

I've been going to make a sail of almost this exact size for the past year for our FB11 and just haven't had the time (plus now we're building the VG23 I can't get the other boat out of the garage!). There is a complete design for a sprit sail in "The Sailmaker's Apprentice" and all the illustrations of sprit sails in that book have the panels cut vertically, although it doesn't state the reason why.

Mick