[C320-list] Boom Repairs for C320

Fri Apr 27 07:55:07 PDT 2018

Doug, 

In the last pic you posted (Forward reefed: https://www.dropbox.com/s/gep5yk51fcmkasc/DSC_0021.JPG)  What is that Ring for that you have just above the boom gooseneck?

Also for the forward block we rigged it similarly but tied a different way.  We fed a line through the reefing cringle, around the shackle on the block and back through the cringle.  Then just knotted and whipped the ends together.  That brings the block up much closer to the reefing cringle so that it doesn't swing around and chafe the sail.  (The carbo blocks are really smooth and don’t seem to chafe anyway).

And for the aft block arrangement, we've found that if you can tie the end of the reefing line around the boom back further toward the end of the boom, you end up with a tighter foot and a flatter sail when reefed (which is what you're really after).

But all in all, we really like that arrangement because even with the main up full, in heavy air you can put a little tension on that reefing line and take a little belly out and flatten the main some.

-Jeff

-----Original Message-----
From: C320-list <c320-list-bounces at lists.catalina320.com> On Behalf Of Doug Treff
Sent: Thursday, April 26, 2018 6:40 PM
To: c320-list at lists.catalina320.com
Subject: Re: [C320-list] Boom Repairs for C320

Art,

I wrote this and shared with the group 5 years ago. It still works great! I highly recommend. I have no recommendations on the outhaul line except to use a plumber's snake to run it.

When we purchased September Song (Hull #350) last August, the previous owner had not rigged any reefing system at all. After a few white knuckle moments where the boat kept rounding up due to being over-canvassed in high winds - we once rounded up so hard that the boat tacked unexpectedly - I decided it was high time that I get the reefing system sorted out.

While doing my research on the factory setup, I discovered that the OEM supplied internal block inside the boom was nowhere to be found on the boat. At that point, since I would be buying all new components, I decided to compare all the different reefing systems out there on the
C320 site along with other single-line reefing systems that I found and come up with something that is easy to operate and not terribly expensive. One of the things that concerned me was that with the factory arrangement, there was potential for a considerable amount of friction because of the line sliding through the aft reef point.

The first order of business was to research the factory reefing system. 
The Association web site was very useful in this regard. Not only do they have a complete owners manual with diagrams of the factory setup, there is also a chart containing the (almost) correct line lengths for the factory system. I also searched the technical photos section of the site and found Jeff Hare's interesting mod to the factory setup where he added ball bearing blocks on the sail at the reef points to reduce friction.

While searching for a suitable replacement for the internal boom block, I contacted Sparcraft-US (formerly Charleston Spar) who made the spars for my boat. I spoke with Robert Quates, who has been with them for nearly 30 years. One of the reefing arrangements that I had been considering was a single line arrangement that I found on Sparcraft's web site. It looked simpler than the Catalina arrangement because the internal block was not used. I was actually leaning towards using that arrangement when I called him. We had a very long and detailed conversation and Robert provided me with some really good advice. It turns out that he actually prefers the Catalina factory arrangement because the floating block in the boom causes the sail to be pulled down evenly as the reefing line is tightened. The problem with the single line system on the Sparcraft site (without the floating block) is that one reef point usually tightens first and then the other one tightens up. This results in uneven pulling on the sail cloth and sometimes an issue where things bind up and never pull up straight without someone going up on deck to assist. That kind of defeats the purpose of the single line system. When the wind pipes up, the safest place to be is the cockpit.

Once he convinced me to go with the factory line routing, he recommended some improvements to eliminate friction and make it work more smoothly.

First of all, he suggested that I NOT try to buy an exact replacement for the internal boom block. Robert said that this block is only a delrin sheave over a Stainless steel shaft with no bearings. Over time these sheaves will bind and not spin freely, which adds friction to the system. Robert suggested that I instead buy a couple of high quality ball-bearing blocks - the non-swivel or locking type to reduce line twist in the boom - and connect them end to end by their shackles. These will perform the function of the missing OEM part while significantly reducing friction. He also recommended that I add blocks at the fore and aft reef points on the sail. These blocks should be the swivel type. 
This turns out to be similar to Jeff Hare's arrangement that is found on the association web site. The line routing is exactly like the owners manual diagram except that I added a swivel block to the forward reef point and secured the bitter end at the base of the mast. Because of this, I added 6 feet to the factory specified length listed in the rigging schedule in the owners manual.

Robert told me that with the addition of ball bearings in the boom, and the additional purchase gained by adding a block on the forward reef point, my reefing system will be nearly effortless. He was right! It should be noted that Robert convinced me to do all this and actually didn't earn a penny for Sparcraft. He's a great resource!

Now that I had the basic plan, it was time to collect the necessary parts. A basic parts list follows:

Qty 4 - Harken 57MM Carbo Air block swivel P/N 2600 Qty 1 - Suncor 1.25" Welded SS Ring PN: C0139-0630 Qty 20 feet - Aft reefing line - 5/16 diameter low stretch Qty 60 feet - Forward reefing line - 5/16 diameter low stretch

First, I took two of the air blocks and locked their swivels so that they would not twist the line inside the boom. I connected them end to end by their shackles. This assembly replaces the OEM internal boom car that is supplied with the C320. Since there was no reefing line rigged in my boom at all, I used a metal plumbers tape to feed the forward reef line from the gooseneck back to the aft end of the boom. Upon exiting the boom, I took the end of the line and passed it through one of the sheaves of my new "car" assembly. Next, I fed the aft line through the other sheave on the car assembly, and routed it through the block that was to hang on the aft reef point. I secured that block to the reef point by passing its shackle through the port side of the aft reef grommet in the sail and capturing the 1.25" SS ring on the starboard side. This ring provides a way to connect the block to the sail with no sharp edges. Ones that was done, the bitter ends of the line are made fast. One of them is tied through the grommet below the reef point and around the boom. The other end is passed through the small hole in the aft end of the boom from the inside and made fast with a figure eight knot. Finally, I routed the remaining end of the forward line back through the boom with my plumbers snake once again, exiting the bottom of the boom at the gooseneck. This forward line is routed up down trough the block on the vang attachment and then up through the final swivel block at the forward reef point and then passed down and tied off at the base of the mast. The forward block cannot be attached to its reef point with a SS ring because the stock sail from Catalina has a smaller grommet in this reef point. I used a short length of reefing line, tied in a knot on the back side of the sail and the block is tied to it. This forward block arrangement is the only deviation from the routing of the lines in the factory diagram.

When all this was done and I tested the system, the aft reef point was not pulling down tight to the boom. After some experimentation, I untied the end of the aft line and shortened it by about 2 feet. Once I did this, it worked flawlessly. The only thing I can think is that adding the extra block forward changed the dynamics of the system and required some adjustment in the aft line to make up for it.

My main halyard is on the starboard side, so I routed the control end of the reefing system to the port side so I could have both lines on a winch at the same time if necessary.

My reefing procedure goes like this:
1. Ease main sheet so main is luffing
2. Lower main halyard until reef point comes down to the boom. I marked the halyard with a black sharpie so I would know approximately how far to lower it.
3. Move to port side and take up the slack in the reefing system. Cleat off once tensioned.
4. Move back to halyard and tension as necessary.
5. Optionally tie off lines hanging in intermediary reef points to bundle loose sail. Be careful not to tie them too tightly. They are not meant to take wind loads, only bundle the sail. If tied too tightly, they could rip from sail.
6. Trim main sheet and you're done!

This whole procedure can be done in about 2 minutes after a few practice sessions.

Shaking out the reef is very similar. Luff the sail, then follow the above steps in reverse order.

I am very pleased with the new system and the setup is quite effortless to operate. The use of ball bearing blocks everywhere has contributed greatly to the system working so smoothly. I highly recommend looking at this arrangement if you are unhappy with your current reefing setup.

Photos:
Aft setup: https://www.dropbox.com/s/rwak1gxic3o9i1f/DSC_0015.JPG
Aft closeup: https://www.dropbox.com/s/akrgxjytcokwbya/DSC_0017.JPG
Aft reefed: https://www.dropbox.com/s/4gre3yxqilt1zgd/DSC_0020.JPG
Forward lower: https://www.dropbox.com/s/tpfb40a0g9zy7a5/DSC_0018.JPG
Forward upper: https://www.dropbox.com/s/rm4h0rzdaafauxi/DSC_0019.JPG
Forward reefed: https://www.dropbox.com/s/gep5yk51fcmkasc/DSC_0021.JPG

--
Doug Treff
doug at treff.us

On Thu, Apr 26, 2018, at 4:58 PM, millers1 at aol.com wrote:
> I have a 2000, #680, non-furling Main Boom.
> Looked on the discussion site, not much on the boom  and  the sketch 
> supplied by Catalina is marginal....
> Has anyone re-run the reef lines and out haul line in the boom???.... 
> any sketches ??   
> Thanks
> Art