Mast question

longy

Overlord of Anarchy
6,733
1,113
San Diego
You have to somehow structurally cover the gap so you can attach sail track. This can be involved, & heavy. As the in-mast spar section is already heavy, you end up with a lot of weight aloft. If the budget allows a whole new spar is great
 
  • Like
Reactions: Mid

tane

Anarchist
903
240
imho this means going to a system with more disadvantages than the one it replaces
 

tane

Anarchist
903
240
in boom furl
advantages:
1. main can be lowered even if mechanism breaks down
2. infinite reefing increments
3. lower CG than in-mast
4. no sailcover (well nearly) needed
disadvantages:
1. boom very heavy, mainsheet/traveller probably not designed for this
2. angle between mast & boom extremely(!!!) critical (do NOT underestimate this!)
3. reefing only possible with AWA <50°. Often boat has to be held head to wind with engine for reefing (the way we used our boats, this would have been completely idiotic & 100% unacceptable & render in-boom f. a dealbreaker/we would have changed to conventional boom/reefing if superb deal)
4.cloth weight has to be very light (same for in-mast f)

in-mast furl:
advantages:
1. infinite reefing increments
2. reefing from the cockpit (mainly)
3. no sailcover needed

disadvantages
1. if mechanism jams with sail out, you're up the creek (I would consider having a sort of sickle-shaped blade ready, that can be pulled up the trysail-track to cut the sail away in an emergency)
2. high CG
3. very light cloth weight
would have been a 100% dealbreaker for us, but as we saw quite a lot of "bluewater" cruisers with in-mast on our last trip I am not so sure any more

my experience with the two furling systems (never had one on our boats): working on a charter fleet that had some Sailtainer in-boom & plenty of in-mast furlers (Selden & Sparcraft).

If reefing from the cockpit is of paramount importance investigate Selden single-line reefing: worked well on our last boat (Elan 410), but lots of line!
 

mgs

canoeman
1,119
251
maine
The above from tane isn’t strictly true.

I’ve seen some rugged and not light weight cloth in boom furling sails. Most of the in mast ones I’ve seen are ‘light’ because they are almost a hundred years old and well worn out.

I know leisurefurl has a video showing them reefing with the wind aft of the beam, so if you like promotional material and their claims there’s that.

Both would reef from the cockpit if the halyards are led aft, and leisurefurl, at least, highly recommends an electric winch.

There certainly pros and cons of each, I’d go with in boom before in mast if I had to, but a conventional boom would be my first choice.

Also, trying to convert from in mast to in boom with the same spar is not the way.
 

tane

Anarchist
903
240
furling boom that "got away":
(the Sailtainer boom on the Bavaria 390 tore away the traveller, & a friend of ours changed his furling-boom back to slab reefing (Grand Soleil 40. The second Sailtainer on the base was a constant source of irritation for everybody: owner, charter guests & base personell. I spent an afternoon in the bosunschair dragging an in-mast-furled main, that the customers had jammed, out... )
 
Last edited:

AnIdiot

Member
424
322
Second Drawer
On a Selden in mast furling rig, if you were to convert to in boom like leisure furl or other would it mean a new stick as well?
IMHO, given the cost of everything else that will need replacing, it wouldn't make sense not to replace the mast, too. It should be possible to find a buyer for the old one to offset the spend a bit.

We have in-boom furling and like it but I'm pretty sure I wouldn't convert from in-mast if I had that.

tane's list of in-boom disadvantages missed a few: you have to hoist the main, which is harder work than rolling it out, unless you rely on electric winches (another, wider, question), the sail cut is relatively flat (shallow chord), so less powerful than a conventional setup (albeit with more size and better shape than many in-mast alternatives), and controlling shape for sail tuning is more difficult, depending on how your boom angle is controlled.

Many HRs and other offshore-capable yachts come with in-mast furling. It's probably safe to assume the owners are happy with the compromises they've made.

I think if in-boom was a solution to all problems it would be more popular. As I say, I like our system and am happy with it but I won't be evangelising; It's all compromises and you have to work out what's going to suit your specific situation with a LOT of significant variables.

If you really want to change to in-boom, then I would think your best approach for success would be to do a complete re-rig, selling the old one and starting afresh with the opportunity to redesign it to suit your usage; reaching out to the designer of the boat for input, if possible.

Alternatively, if the boat was originally designed for in-mast, then some of the issues (weight aloft, for starters) should already have been addressed; if it wasn't then you could look for an original mast to retrofit?
 

CriticalPath

Anarchist
695
181
BofQ
The above from tane isn’t strictly true.

I’ve seen some rugged and not light weight cloth in boom furling sails. Most of the in mast ones I’ve seen are ‘light’ because they are almost a hundred years old and well worn out.

Perhaps things've changed in the past few years, but when I worked in a sail loft (15-20 years ago) we built two mainsails for boom furling (Leisure Furl and ProFurl).

Both specified significantly smaller, lighter, and thinner construction details (corner patches and batten pockets) than optimal. They also suggested cloth weights that were suitable for Great Lakes (i.e. lighter) than typical cloth manufacturer's recommendations.

Mainsail construction for mast furling mainsails is similarly compromised.

YMMV...

Cheers!
 

mgs

canoeman
1,119
251
maine
Perhaps things've changed in the past few years, but when I worked in a sail loft (15-20 years ago) we built two mainsails for boom furling (Leisure Furl and ProFurl).

Both specified significantly smaller, lighter, and thinner construction details (corner patches and batten pockets) than optimal. They also suggested cloth weights that were suitable for Great Lakes (i.e. lighter) than typical cloth manufacturer's recommendations.

Mainsail construction for mast furling mainsails is similarly compromised.

YMMV...

Cheers!
I scanned the leisurefurl sail-makers instructions online, and I didn't see anything regarding cloth weight. However, none of it made much sense to me so it could have been right there and I just dont know what I'm looking for...
 




Top