O'Day 20 Mainsail

[CHris F]

I have a PDF of the rigging instructions for our "new to me" 1976 O'Day 20. In it, it states to raise the mainsail fully, and then insert a cotter pin through the mast to keep the luff slugs from falling out when the sail is lowered. This makes sense, however when the sail (which is not original, but was purchased from a club member who had purchased it from Precision Sails for his old O'Day 20), the boom is pulled above the slot in the mast when it is attached. I can then use the cotter pin to hold the boom up, rather than the sail luff slugs. My question is which would I do, raise the sail to it's highest point, thereby having the boom higher, or follow the instructions in the manual and not have the sail raised as high as possible. Comments are greatly appreciated as I get the hang of our new boat.

 

[Siamese]

I had an O'day 20 and liked it a lot, but it was about 12 years ago for just one season, so I can't recall how the boom was rigged. But...

Assuming the boom is able to slide up and down in the track and isn't permanently attached to a fixed point, it would make sense that the boom would somehow be limited from rising too far by a pin or something. Find out how that's accomplished, and then raise the sail all the way. It might not go all the way to the top, but it's important that you're able to tighten up the halyard to get good tension on the luff. If the boom isn't restricted from rising past a certain point, you won't be able to achieve that tension.

How about posting two or three closeup pictures, and I'll bet you get some useful answers.

P.S.
You might be misinterpreting "raise the main fully". That doesn't necessarily mean all the way to the top of the mast, but as far as it can go with the boom in it's proper place. Raised "fully", the tack may be a few inches from the top.

 

[CHris F]

I had an O'day 20 and liked it a lot, but it was about 12 years ago for just one season, so I can't recall how the boom was rigged. But...

Assuming the boom is able to slide up and down in the track and isn't permanently attached to a fixed point, it would make sense that the boom would somehow be limited from rising too far by a pin or something. Find out how that's accomplished, and then raise the sail all the way. It might not go all the way to the top, but it's important that you're able to tighten up the halyard to get good tension on the luff. If the boom isn't restricted from rising past a certain point, you won't be able to achieve that tension.

How about posting two or three closeup pictures, and I'll bet you get some useful answers.

P.S.
You might be misinterpreting "raise the main fully". That doesn't necessarily mean all the way to the top of the mast, but as far as it can go with the boom in it's proper place. Raised "fully", the tack may be a few inches from the top.

Thank you - I will post pictures when I get back to the boat. In answer to your question, there is nothing to prevent the boom from raising up when raising the mainsail, the boom is "held down" only by pulling down on the line attached to the gooseneck and attached to the downhaul cleat.

 

[Sunbird22358]

What year was that "older" O'DAY 20? If she was older than 1976, the main is too small for a 1976-78 model. O'DAY switched to a taller rig in 1976, 1973-75 had a masthead style rig (forestay attached at masthead, jib goes to masthead), 1976-78 models had a fractional rig (taller, with forestay attached about 3/4 of the way up the mast, same point as upper shrouds)

 

[CHris F]

She is a 1976 with a fractional rig.

 

[Siamese]

Okay, so it sounds like your main is simply too small for the mast?

Until I got a new sail for it, I would put the boom in the proper spot, somewhere below the pin that keeps the sail slugs from falling out when you lower the main. And, hold the boom in place with the downhaul line you mentioned. The sails won't go all the way to the top of the mast, but much more importantly, you'll be able to get proper tension in the luff.

Unless you find yourself in a race on a light wind day, it's not going to matter much if the main doesn't go all the way to the top. On really windy days...bonus... you already have a small reef in the sail!

Yeah, I really liked my O'Day 20. Had a nice little cabin, and sailed very nicely. I'd get my main and jib trimmed, tie off the tiller, and go sit in the bow pulpit while she sailed herself.

 

[Sunbird22358]

She is a 1976 with a fractional rig.

So, if the boat that the mainsail came from is the same year as your boat (both are 1976 models), it should be the correct size for your boat. Does your sail have a boltrope along the luff (leading edge)? If there is a boltrope (and even with those slugs it COULD still have a boltrope) then you will need to stretch the luff of the sail as you raise it to get it to full length. The boltrope is purposely made shorter than the luff out of a stretchy rope, That allows some adjustment of the belly of the sail, my DS II has that type of setup on the main and I have to stretch it out each time I raise it. I do this by raising it as much as I can, then with the halyard hooked over the bottom of the cleat, I grab the halyard abut 2' or so above the cleat a pull it away from the mast, then quickly pull the end of the halyard again to take out the slack created. I repeat this 2-3 times to get the sail up the last few inches. If the sail is all the way up to the head of the mast but the boom seems high, pull down with the downhaul to fully tension the luff. Does your mast have a stripe about at the point on the mast where the boom is shown in the drawing that I posted above? If so, that is the theoretical designed height of the gooseneck for proper sailset with the head of the sail all the way up.

 

[pkpdjh]

I have similar questions about this exact boat. Mine is a '77, so it is definitely the fractional rig and this weekend we noticed that by pulling head of the sail to the top of the mast we also came close to putting the gooseneck as high as the opening in the slot. I like Sunbird22358's idea of using the downhaul and halyard together to possibly lengthen the luff. Our boat definitely has a downhaul in place, so possibly with a little experimentation, we can get the head of the sail to the top of the mast, without having the gooseneck too high. The previous owner, a very knowledgeable sailor, assured me we should be putting the head of the sail to the top of the mast. I think the answer will be to secure the downhaul such that the gooseneck can rise to a point, just below the slot opening, then pull hard on the main halyard. The previous owner told me it would require some winch power to get the main as high as it should go. I might be making a detour on my trip up north to the marina and I will try to get some pictures of my boat.

 

[Sunbird22358]

I'm not sure if this will help on a sail that has slugs, but on my DS II with the boltrope sliding into the groove on the mast, I give the groove slot a rub of candle wax each Spring and that makes raising the sail A LOT easier! It reduces the friction of the boltrope in the groove and helps me get the sail all the way to the top. With the slugs, there should not be much of any friction between the slugs and the mast slot, but a little polishing of the slot with a mild scotch-brite pad couldn't hurt.

 

[LordNelson]

I raise mine to the top and then pull down on a line attached to the bottom of the boom to tighten the tension and cleat it on a cleat on the mast located in the sail slide groove. I have a sail slug witch has a thumb screw wheel to tighten it inside the groove which keeps the sail from sliding down. I do move this slug when I use the boom to reef which if you pull back on the boom allows you to roll the main on it like a window shade.

 

[pkpdjh]

Lord Nelson, thanks for the info.

Does this mean that when you pull that downhaul attached to the bottom of the boom, the boom always comes below that opening in the slot in mast?

Do you notice that the boltrope stretches some like was suggested earlier?

By the way, my previous owner installed jiffy reefing which works very nicely, although I do like the rolling boom. Do you use that to roll up the sail at the end of the day? I'm thinking that might be easier than flaking.