How hard/$$$ to replace furling main with a proper battened one?

[EarthBM]

Hi, I am considering buying a 20 year old 45ft cruising cat. The main turnoff is the sailplan -- it has a lame small furling main for its size and weight.

The plan is to sail it up the (US) West Coast in Spring/Summer 2011, then Transpac to SE Asia, then on to Europe around the Cape of Good Hope (or Cape Horn if feeling brave).

Question 1: How hard/costly is it to replace the main with a proper fully battened square-toppish one? Can use the same mast?

Question 2: What is the approximate performance hit from the furling main, compared to a properly shaped sail? Are there polar plots for the boats >35ft with furling vs battened sails?

I am a newb here, so please feel free to trample on my feelings like others have done troughout my life.

[sailingdog]

Originally Posted by EarthBM

Hi, I am considering buying a 20 year old 45ft cruising cat. The main turnoff is the sailplan -- it has a lame small furling main for its size and weight.

The plan is to sail it up the (US) West Coast in Spring/Summer 2011, then Transpac to SE Asia, then on to Europe around the Cape of Good Hope (or Cape Horn if feeling brave).

If you're in SE Asia, going to Europe via Cape of Good Hope makes a lot more sense than backtracking to go via Cape Horn.

Question 1: How hard/costly is it to replace the main with a proper fully battened square-toppish one? Can use the same mast?

Can't really price the sail for you, since it depends on what material you're getting it made out of, as well as what options you're putting on the sail—number of battens, number of reef points, telltales, stackpack, etc.

Yes, but adding roach to the mainsail by adding battens will shift the center of effort aft, and likely lead to more weatherhelm.

Question 2: What is the approximate performance hit from the furling main, compared to a properly shaped sail? Are there polar plots for the boats >35ft with furling vs battened sails?

Can't really say. Polar plots are pretty boat specific...so you probably won't find one that is applicable to your situation.

I am a newb here, so please feel free to trample on my feelings like others have done troughout my life.

[EarthBM]

Thanks! Yes, Cape Horn would be a destination in itself (always wanted to), if find myself running high on heroism and low on accumulated damages.

I guess the main question is about the mast - can the same mast be adapted? Cost of the sail would be there anyway because I suspect the current main is not in great shape. If I have to replace the mast than this is a no go.

More weatherhelm is clear (and probably not that great on a cat, don't want more apparent wind in a puff), but the boat seems a bit underpowered now, so this is likely not a problem. Besides some can probably be fixed by tightening the forestay, no?

I am just guessing that some manufacturer somewhere must've offered a furling "touring" rig and a battened "racing" rig on the same boat (hopefully with the same mast height), providing polar charts for both. Then this would give me a general idea for performance difference (eg furling 75% of battened in 10kt on beam reach, etc...)

[sailingdog]

Is the main an in-mast furling main? If so, you may need to replace the spar or modify it. Replacing it would reduce weight aloft, since you won't have the furling gear in the mast anymore.

[EarthBM]

Originally Posted by sailingdog

Is the main an in-mast furling main? If so, you may need to replace the spar or modify it. Replacing it would reduce weight aloft, since you won't have the furling gear in the mast anymore.

It is, alas. And by replacing the spar you do mean the whole mast needs to be remade, with spreaders, etc?

Is there somewhere I can check the cost (and once I am at it, for a proper rotating mast cost?)

[Faster]

Originally Posted by EarthBM

Question 1: How hard/costly is it to replace the main with a proper fully battened square-toppish one? Can use the same mast?

That's a pretty radical change that I doubt you'd be able to do with the same mast. The fathead main will put a lot more load on everything.. and I suspect routinely hoisting/dousing a mainsail on what is meant to be an in-mast furling foil will not go well... for best results you need a proper mast section with a sailtrack - and for a large roach full batten sail something like Harkens Battcars (all $$$$$$) would be the way to go.

[sailingdog]

Well, you could move the a lot of the hardware over from the existing mast, but it would be a lot of work and unless you did it yourself, it would probably be more expensive than buying the entire mast.

You'll probably have to replace the rigging too—and given the age of the boat, that might not be a bad idea.

Originally Posted by EarthBM

It is, alas. And by replacing the spar you do mean the whole mast needs to be remade, with spreaders, etc?

Is there somewhere I can check the cost (and once I am at it, for a proper rotating mast cost?)

[EarthBM]

Originally Posted by Faster

for best results you need a proper mast section with a sailtrack - and for a large roach full batten sail something like Harkens Battcars (all $$$$$$) would be the way to go.

Battcars! I like it!
So the avenue to explore is whether there is enough space to add an external sailtrack to the mast. Then I can even retain the original furling main as a spare/storm sail (if the weight is not too great).


That points me in the right direction, thanks!

[Hudsonian]

Is the designer still around? If so, this may be a source of information on such a modification. If it has been done, the designer may well have been involved in the modification. If not, the naval architect could guide you in implementing you diea.