Way back in the 1900's when I started this 30' (9m) cat build, and before I knew really much about anything, I purchased a used mast (came off a monohull) that was "about" the right length for the Kurt specified mast. Since, he has updated his drawings and the mast now is over a foot shorter. It has other shortcomings as well - only one set of spreaders, the width moment specified is 6 in4. and mine is 5 in4. The long dimension moment is ok. The mast head has smaller sheaves than spec'd. The head is also welded on, and if cut off the mast would be even shorter. Specified at 37' 7" (11.5m), mine is about 36' 4" (11m). I added a cuddy cabin and the boom would need to be raised now maybe another foot or .3m, making the mainsail even smaller. It has only one set of spreaders, and is not set up for a fractional rig as the design wants.
The other day I called a rigger about perhaps setting up my mast for synthetic shrouds and he talked an hour about why I should not have a shorter mast from design, as well as other considerations. I am to the point of spending some money on this mast to get it set up to work, and then would need know these things to get a good mainsail design. But he got me thinking that perhaps I should seek a proper mast for the design. He admitted it is dependent on use, and unstable weather in NW Alaska could allow for a smaller rig, but these things I just don't know about (except for the unstable weather).
Budget is a big factor. At this point I could probably have a motor boat, but to set up for sailing may take a next year launch, so I have a little time. Just a month or two left in this year's season. I have a couple choices. Use what I have and get a mainsail that would work with it, or purchase a new (used?) mast. That way I may even get one that is a bit more toward a wing mast. Mine is an Isomat NG37 off a Beneteau mono. I've yet to acquire a step for it or build one (rotating is the design). I suppose a third option is to build a mast. Wonder if anyone else does that? I asked Kurt about it - he has plans for a plywood/carbon mast that might not be too expensive to build - but he would have to modify his drawings for my size boat. I did build the boom using that technique. Being up in Nome, Alaska, I don't really have the option to have a rigger come up and help out, and it would be difficult to shop for a used mast since I am off the road system.
The other day I called a rigger about perhaps setting up my mast for synthetic shrouds and he talked an hour about why I should not have a shorter mast from design, as well as other considerations. I am to the point of spending some money on this mast to get it set up to work, and then would need know these things to get a good mainsail design. But he got me thinking that perhaps I should seek a proper mast for the design. He admitted it is dependent on use, and unstable weather in NW Alaska could allow for a smaller rig, but these things I just don't know about (except for the unstable weather).
Budget is a big factor. At this point I could probably have a motor boat, but to set up for sailing may take a next year launch, so I have a little time. Just a month or two left in this year's season. I have a couple choices. Use what I have and get a mainsail that would work with it, or purchase a new (used?) mast. That way I may even get one that is a bit more toward a wing mast. Mine is an Isomat NG37 off a Beneteau mono. I've yet to acquire a step for it or build one (rotating is the design). I suppose a third option is to build a mast. Wonder if anyone else does that? I asked Kurt about it - he has plans for a plywood/carbon mast that might not be too expensive to build - but he would have to modify his drawings for my size boat. I did build the boom using that technique. Being up in Nome, Alaska, I don't really have the option to have a rigger come up and help out, and it would be difficult to shop for a used mast since I am off the road system.
