Boom to slab reefing sail conversion please.

mickshep

mickshep

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Quick question before opening the first beer of Christmas. Present boat is fitted with boom roller reefing, (The old type where the entire boom rotates). It goes without saying that the sail shape will rapidly deteriorate as it is wound in. As the main is almost new, replacement is not an option. Is having suitably reinforced reef cringles fitted at leech and luff as well as pennant eyes accross the sail a realistic option or is it not as simple as that? The boat is a comparative lightweight compared to my other boats (Shipman 28. Fin and skeg, about 3 tonnes) and apparently they can be crank if well heeled. If slab reefing can be retro fitted to the main, can I also incorperate a flattening (Cunningham) reef? Cheers in advance and a Happy Christmas to all. Mike.
 
Many roller reefing booms had the gooseneck on a short length of track. If you have this type; instead of fitting a Cunningham all you need is a tackle to pull the gooseneck down the track. I have this arrangement and it works fine; it also makes setting the mainsail easier because you can hoist the sail with the halyard without needing a winch, then haul downwards on the aforementioned tackle to tension the luff.
 
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Many roller reefing booms had the gooseneck on a short length of track. If you have this type; instead of fitting a Cunningham all you need is a tackle to pull the gooseneck down the track. I have this arrangement and it works fine; it also makes setting the mainsail easier because you can hoist the sail with the halyard without needing a winch, then haul downwards on the aforementioned tackle to tension the luff.

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I have that arrangement on my boat, and yes, it does work well. /forums/images/graemlins/smile.gif
 
Quick answer is, 'Yes you can'.
I did it myself some years ago. However, I did not bother with reefing pendants. IMHO they do not really contribute to the shape and only serve to hold the bunt in place. I believe that they should not have any strain on them.
What I did do was to sew a strip of heavy sailcloth tape, 50mm wide, from one reef cringle to another (luff to leech) to take the strain. At that stage the sail becomes a 'loose-footed' main. The bunt is held loosely in place within the confines of the combined lazy jacks / sail catcher, which is also home made.
I don't do racing on this boat so any theoretical inefficiency does not bother me.
BTW I am not sure if the word 'bunt' is the correct term; by bunt I am meaning that part of the sail that has been removed through reefing and that lies like a loosely folded tube along the top of the boom.
 
I had a Shipman 28 in 1982 and converted the roller boom to slab reefing using one of the Barton kits which I believe are still available and had the sail modified by Arun sails.As I was broke at the time(and am now for that matter) it couldn't have been expensive!
I didn't bother bringing lines back to the cockpit as that would have just added to the expense,neither did I find it necessary to have a reefing winch.
Made a tremendous difference.
Nice boats,point well and not to shabby off the wind,a poor mans CO32.(I was told).

http://www.bartonmarine.com/home.asp?page=home.htm

An unscrupulous person would look at the Barton kit and make up their own.
 
You can change it and even keep the old boom but you'll need to fit the cascades inside the boom unless you run them outside.

Also means you can have a proper vang.

A cunningham can easily be incorporated in the setup.

If you do this you need to decide if you're going to have the lines led back to the cockpit. Thus you can have outhaul, cunningham, first, second, third, main halyard, genoa halyard, spi halyard, spi pole uphaul, spi pole downhaul all led back to thr coachroof winches. Only problem with this is that is a lot of hardware to buy, 2 x 5 organisers, 2 x 5 clutches, 2 x 5 blocks at mast base, plus mods to sail , plus six turning blocks for the boom, plus four stops for the reef lines. Oh and the reef lines themselves.

Best bet is a boat jumble for that lot.
 
How's the Christmas prep' going down your neck of the woods? Re' your post I'm a bit confused now. surely hauling down on the gooseneck slider will just tighten the luff, Isn't the cunningham a single cringle at the luff a short distance up from the 'proper luff cringle without a corresponding cringle in the leach. I thought that taking what is in effect a small slab reef out at the front of the sail just took out some of the belly therebye flattening the sail prior to a full reef being needed. Blinkin ek! I've just read that back and confused myself totally. Theres cringles everywhere. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif Happy cringlemas /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif to everyone. Regards, Mike.
 
Hush Man! Christmas is gonna be nice and quiet, well it was until some armole down the road thought it would be ever so jolly to let off some bloddy fireworks.............freakin plonker!

Re cunningham......well I have a tackle as already mentioned, and it will (in conjunction with the outhaul) flatten the sail quite nicely. However, I do have new sails to fit in the spring, the main is loose footed, and 3/4 battened (Kemp Powermain) so I don't know how it will work with that, gonna have to suck it and see. If anybody reading this has any comments I would be interested, as long as they aint of the Foxtrot Oscar kind!
 
This is not a difficult conversion and one well worth doing.

Use a barton kit, as has been posted by other formites and it will improve the sail shape out of all order to the cost.

You will find that it will set even when well reefed.

Well worth doing.

Iain
 
Short answer to the original poster is yes.

I reckon you may find especially on a mast head rig with small main that one reef will fill most of your needs. Make it about 12% of the way up the luff. This will reduce sail area by a lot more than 12%.
The eyelets for tidying up the bund are optional but I do think you should have one at least near the luff. Cos on the wind the bund seems to billow out full of wind then perhaps another one about mid way along the foot. and a few more if you are feeling like it.

If you are to be able to pull ion a reef at sea it is vital that the reef line at the ned of the boom is led at least to the mast so that you can reach it with the boom allowed to swing way out. I very much advocate back to the cockpit. It will require a turning cheek block on the side of the boom alittle aft of where the eyelet will meet the boom when reefed. ( to provide outhaul pull) I think under the boom external is ok for the reefing line ,you can firt some small saddles to run the rope under to keep it tidy.

You need an attachment at the clew (front end of boo) to both hold the eyelet dwn against the halyard and forward against the outhaul pull. Some boats have a rams horn fitted. I prefer a rope line not unlikethe outhaul reefing line. Again back to the cockpit is best. Both lines need to pull at about 45degrees to horozontal to provide equal pull down and also to stretch out the foot.

If you are sure you will only reef before depature when moored then reefing can be acheived really well with a light rope lashing the aft cringle down to the boom and also out to the boom end (outhaul)
Similarly at the gooseneck you lash the eyelet around the boom to pull down and also around the mast to pull forward.

I am not in favour of single line reefing 2 lines is best. In all cases you will eed the eyelets fitted in the sail. I don't think you will be dissapointed with proper reefing.
You might consider the option of a flattening reef eyelet which is like the equivaleent of the cunningham eye but at the aft end (about 6 inches up from the boom) and can take a lot of camber out of the sail without reducing area. good luck and happy Christmas olewill
The gooseneck on a track works well on smaller boats but be aware the amount that you tension down the boom is lost headroom under the boom which may or may noit be a consideration
 
One of the cheapest and easiest options for you is to get a length of moulded foam pipe insulation, a little shorter than the sail foot, and secure it (with a tie at each end) along the boom. When you reef, the foam gets trapped in the sail as it rolls and the sail shape is preserved. I have tried this, and it keeps the boom level and the sail flat as you reef. I admit that it is a bit 'Heath Robinson', but it works, and is very cheap!!
 
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