Well the new mainsail is going great, but the old stack pack on my boat finally spat the dummy. The extra bulk of the new sail compared to the old one has put too much stress on everything, and it basically exploded last weekend. I'm not surprised...

We're planning on building one ourselves, but I thought you guys might have some experience and advice before we dive in? Best suppliers for materials?

Weathermax as a material, slugs along an open bottom (loose footed main), heavy duty zip with a cover flap, and lazy jacks built in. Rather than have the vertical mast zip directly forward on the mast, we plan to wrap it all the way around and locate the zip in line with the main halyard where it enters the mast sheeve.