main sail slab reefing

[rogerthebodger]

Has any one fitted reefing blocks to the reefing points of their main sail to help reduce friction at the for and aft points on the main sail where the reefing line would normally pass through the sail on a single line reefing system.

If so what type and pls indicator the supplier.

 

[FullCircle]

Yes, my main has the sheave blocks at all reefing points.
Don't know the supplier though. MAybe pick up a second hand main thats worn out and remove the blocks?
My old main had blocks that were perfectly serviceable.

 

[charles_reed]

Has any one fitted reefing blocks to the reefing points of their main sail to help reduce friction at the for and aft points on the main sail where the reefing line would normally pass through the sail on a single line reefing system.

If so what type and pls indicator the supplier.

I've used, with success, for the last 6 years Harken 40mm Airblocks for my two lower reefs. My mainsail @ 32m2 is close to the limit recommended by them.

www.harken.com/pdf/4927.pdf

I found Harken US to be far more helpful, competent and with a wider range of stock then their UK operation.

Rutgerson also introduced an in leech-hole reefing roller, I saw it some 6 years ago at the Barcelona exhibition, but it needs to be included by the sailmaker, whilst the mainsail is being made.

The normal cringles have a double-ring tape through them, to which the Airblock is attached.

On anything but the most minute mainsail, frictional loss makes single-line reefing unfeasible, using the normal lines.

 

[rudolph_hart]

My mainsail is the same size as Charles Reed's and also has the same 40mm Harken blocks - standard fitting by the builder (Dehler) - which haven't bent or distorted with use over the years (16). I did downsize the original 12mm reef lines to 10mm Dyneema to further reduce friction, though.

 

[srah1953]

I don't really know enough to offer any kind of authoritative advice but I do want to give one warning. My main (35 sq m) came with blocks at the front but none at the leech. I found taking in and out reefs quite difficult so I added blocks at the leech. I cannot say that I found that it made much difference and am now experimenting with and without blocks to see what difference there is.

My warning - the Lewmar synchro luff blocks (http://www.lewmar.com/products.asp?id=7906&type=117&channel=1) provided by the sailmaker caught on the sail (between the sheave of the block and side plate) near the luff on a number of occasions when the halyard was dropped and eventually tore the sail. Whether the fault is mine or the shape of the lewmar block ..... Anyway, you have been warned.

 

[simonfraser]

if you let the sail down sufficiently and raise the boom to meet the luff point i can't see the need for blocks on the sail. oh, pointing to wind will help too

you have got a winch to pull the reefing line down ?

harken do carbo tie on blocks, they would do and and leave some flexibility if things get caught, but see above.

 

[rogerthebodger]

Thanks Guys.

My main reason for wishing to have blocks on the reefing points is to have single line reefing from the cockpit with as little friction as possible and being as my main is currently being checked out by my sail maker I wished to include them.

I spoke to a mate who works of Harken also from this parish, who recommended 75mm ESP blocks attached to double-ring tape through the normal cringles as per charles_reed.

I need larger blocks as my main is about 43 sqm.

Thanks once again Guys

 

[jonjo]

I've used, with success, for the last 6 years Harken 40mm Airblocks for my two lower reefs.

How do the blocks sit under tension when a reef is tucked in? I ask because I am concerned that the block could put an awkward side load on the cringle and risk pulling it out.

 

[chrishelen]

My new to me boat has double line reefing feeding back to the cockpit and to be honest its a PITA to raise and lower the main,it has blocks on the front of the sail and when reefed it all looks ok, but i am thinking of taking the lower reef out and just having the second reef half way up the sail to reduce friction and the pieces of string in the cockpit.

 

[charles_reed]

How do the blocks sit under tension when a reef is tucked in? I ask because I am concerned that the block could put an awkward side load on the cringle and risk pulling it out.

The tape gives a lead of 60-70mm so the pull is definitely downward, not sideways.

One of the problems with Dyneema (which I'm using) is that it tends to twist, careful relaying of the lines gradually gets rid of this over time.
When reefing you need to balance the vang and luff tensions to get a flat reef, otherwise all the tension goes on the luff and you get a great belly in the sail, where the leech line hasn't pulled the sail in sufficiently.

In the sail up from Crete to Mesolonghi, I put in and let out the 1st reef 15 times and the 2nd reef 5 times. Winds were up to F7 reaching and I was using the working jib, rather than an overlapping genoa.
Being able to reef (I sail singlehanded) from the cockpit is a boon, but due to the 4:1 tackle, the second reef produces an enormous amount of string in the cockpit.

 

[rogerthebodger]

Charles do you have any pics of your reefing points as my sail maker is not with how to attach the blocks to the my main sail

Thanks again Charles

 

[charles_reed]

Boat Mesolonghi me Waters Upton.

tape with a 32mm ss ring, put through reef cringle (luff and leech) and another 32mm ring sewn in at the other end so the tape is captive.

The airblocks have a swivel and D shackle. This attaches to one of the rings (which side of the sail depends on the position of the next sheave.

1st reef is external, bitter end at leach-end of boom, up to the block on the sail-leach, back to a cheek-block on the side of the boom, aft of the leach cringle.
From there the line goes to a cheek-block on the luff end of the boom to the airblock on the luff-reef point - thece to a cheek block on the mast and from there to the mast-foot block and back to the cockpit.

2nd reef uses the same serial progression, but the line goes through the old reef-line in the boom to a cheek-block on the mast, thence to the luff-block and down to the mast-base and back to the cockpit

Line from

 

[rogerthebodger]

Thanks Charles

I will give my sail maker you description next week when I am on my boat in Durban and hope he gets it right, if not I will find another sail maker.

 

[rudolph_hart]

Thanks Charles

I will give my sail maker you description next week when I am on my boat in Durban and hope he gets it right, if not I will find another sail maker.

Just to give you another take on the cringles:

on my Elvstrom mainsail, the web/tape is doubled over and sewn to the leech below the cringle. The resulting loop protrudes through the cringle to the other side, and it is to this loop that the airblock is shackled. IMHO it gives a 'fairer' pull on the cringle when the reef is put in. I guess that the pair of 'up' and 'down' sheaves at each end of the boom need to be on the same side of the sail for this to work properly.

Hope this helps

 

[blackbeard]

Has any one fitted reefing blocks to the reefing points of their main sail to help reduce friction at the for and aft points on the main sail where the reefing line would normally pass through the sail on a single line reefing system.

If so what type and pls indicator the supplier.

Yes, at both luff and leech although luff is more important.
Can't remember offhand the supplier but any small ball-bearing blocks with a decent working load will do the job. As my boat is a Hunter 245 the load won't be very great.
Blocks are tied in place using a bit of line and can (in theory) be moved easily and rapidly to 3rd reef position though I would expect to do this in harbour if there was a bit of a blow forecast.
Have also used thinner reefing line to reduce friction which is your enemy on any form of single-line reefing.
Would recommend some such system which works reasonably well, which could not be said of original set-up (heavy lines passing through cringles) which was hopeless.