[sailing320]

I am purchasing a new mainsail for my IP which has an inmast furling system. Speaking to several sailmakers some have recommended a cross cut sail and others a radial cut. I am trying to get information on which would be the best performing sail and why. I understand the radial will be more money. My mast does not have the opening for vertical battens.

 

[jason3317]

I don't see any real advantage to using a radial cut dacron sail in your particular application. Radial cut sails orient the panels to the load at the head, tack and clew, which are the primary load points. With the concave, no-roach mainsail cut you will require....I don't see the benefit.

If you are willing to up-rate your sail to a radial laminate, that might make sense. For example, North's Norlam cloth is Dacron-Mylar-Dacron in a radial cut. The radial laminates will have more ability to hold their shape. Often you see cruising boats with radial laminate headsail (genoa) and a cross-cut dacron mainsail...a good compromise.

 

[RichH]

Since you have in-mast furling, you probably won't/don't take advantage of a cross cut - adjustability of shape by 'edge tension' - foot, luff, leech, cunningham, etc. etc. etc. etc. Therefore, a radial cut, which is more shape stable than a cross cut will probably be your best optimum (for in-mast furling), .... and regardless of material chosen.

 

[jason3317]

I've never seen an Island Packet with a Cunningham, that's for sure. Don't they just roll it up and motor when it blows hard enough to warrant moving the draft forward. Kidding.

An in-mast furling main will by necessity need to be cut somewhat flat. I am not an IP expert, but I would believe that most of the power is generated from the headsails.....hence my recommendation on the radial cut genoa.

Price out the cross-cut vs. radial mainsail (in Dacron, not laminate). I think you will be surprised how much more $$$ the radial cut is, for imho, not much gain.

Are there other IP owners out there to chime in? I'd like to know what the consensus is among that group before I'd make a decision.

 

[sailing320]

I can get a radial cut for the same price as a cross cut. I'm using high quality dacron. The weight of the the radial can be less so it might be easier to furl the sail in/out.

 

[jason3317]

Less weight is better, of course. If you can get similar pricing on both cuts...the radial is the way to go.