Replacing missing fiddly-bits

[McNemo]

I've been working on my used Sun Cat for a few weekends to bring it up to my standards before her first launching.  This included a complete redo of the bottom paint, installing sheet bags in lieu of the 3M sticky-tape closet hooks the last owner used  , and generally refreshing anything that could be cleaned.

I finally had a chance to set everything up this morning and I found a broken area on top of the piece where the gaff connects to the mast, top area of the slidey bit that rides in the channel. I'm not well versed in modern rigging,  but I suspect this is where I should be able to attach the main halyard?  Am I correct,  and if so where can I find a replacement?

Also MIA is the pin for fixing the rudder in the vertical position.  I suspect previous owner also reassigned it to the tension bracket on the forestay. What are those kinds of pins called? It seems like a good idea to find several to have on hand.

Thanks for your help!

[Jim in TC]

As it happens I was just looking at that piece not long ago, but still can't remember just what it looks like (and the boat is down at the marina now). But I am thinking you are correct to expect a place to affix the halyard. Someone with a better memory (or a bit of rigging right out the door) can confirm. But the bottom line for parts like this - that are not necessarily generic - is ComPac itself. There is an easily found and browsed parts list at https://www.com-pacyachts.com/ (go to the SunCat page and look near the bottom of the page). I once needed a rigging bit that was in my hands (at some expense for shipping) the next day. Call them during their business hours and they will set you right up (and answer any remaining questions while at it). If the rudder is original, they can help you diagnose that issue as well.

[bruce]

Com-Pac sources its spars and fittings from Dwyer Mast. For the SC, the mast is extrusion DM-375, the boom is DM-275, and the gaff is DM-1. In the past you could order directly from Dwyer, but I just checked and as of 8/1/23 they have suspended their online and telephone ordering for retail sales. Unfortunately their excellent interactive website, with exploded parts diagrams for things like the gaff gooseneck, has been disabled.
https://dwyermast.com

At this point I agree with Jim, go to Com-Pac. The part you need is the gaff gooseneck slide, Com-Pac lists it as part #MC00G0000, for $96.20. This should get you back to stock.
https://www.dropbox.com/sh/xtfxq40jvl9esw9/AADHttjwMACdw5Voo2NYBoLVa?oref=e&preview=SUN+CAT+2023.pdf

Unfortunately, many have had issues with the stock gaff gooseneck slide. Here are a couple of threads to get you started.
https://cpyoa.com/forum/index.php?topic=10938.0
https://cpyoa.com/forum/index.php?topic=9024.0

In Jim's thread, I posted the parts diagram for the gooseneck in question (see Reply #24). The slide is DH 4151S. Com-Pac modifies the slide by replacing the ring with an extended ring on a 2" stalk that is oriented up, on top of the slide. This was done to gain clearance in the throat, the slide and throat halyard shackle were being pinched between the gaff and mast. But, even after the fix, significant pinching continued and many, if not most, extended rings have been bent to the side causing the slide to bind in use. Some extended rings have broken off from metal fatigue from repeated bending. Read through the threads, if you don't have scarring on top of your gaff at the throat as seen in several examples discussed, evidence of the pinching, you'll probably be OK with the stock slide. If you experience pinching, then the standard slide Dwyer provides, with the ring oriented down, solves the problem as detailed in the threads.

Sorry to confuse things, but I wanted to bring it to your attention now rather than later. Com-Pac has never acknowledged the problem that I've seen. Post a photo of what you have and we can better advise.

[McNemo]

Thanks guys for that information.  There is definitely some scarring present on the gaff that matches your description.  If this photo will load you can see what I am dealing with.

[bruce]

Yeah, snapped right off. There's no great stress raising the sail!

You saw what I did as a work around. I suspect the boom gooseneck slide would be fine, ring down. Com-Pac seems to list it as part # MR00S0041, for $90.00! I don't think they modify this part, so the mark up is BS. You have one already on the boom to compare to the gaff gooseneck slide.

Otherwise, you could rig something temporary with what you have. You could grind off the broken stub and mount some kind of attachment point, or just tie off through or under the gooseneck. Good use for some thin and strong line like Dyneema.

[Jim in TC]

I agree with Bruce that you could get out on the water with some jury-rigging; another option might be to go to a welding shop and have them grind on it, and weld an eye on. It should be pretty easy work for them, and cheaper than a new part. Can you see any downside to that option?

I might be tempted, too, to push the fitting into the gaff and add a screw from the top. The clearance I see in the photo will only expand and perhaps, at some inopportune time, fail.

I am often impressed with Bruce's ability to retrieve old and relevant threads!

[bruce]

Here's a couple of photos of how another PC owner attached his throat halyard. He'd modified his halyard purchase to 2:1, as I have, so a block is attached at the throat rather than the stock shackle.

A line is very forgiving to the pinching in the throat, and easy to inspect for chaffing. The slide will run best if the halyard is pulling up on it directly. Just as with the extended ring bent to the side, a new attachment further away on top of the gaff, coupled with the attendant flexing in the gooseneck, the slide may bind some. You could experiment with a ring temporarily mounted on top of the gaff with a hose clamp to see if this is an issue.

[Jon898]

Bruce:

Wouldn't all this be avoided if you follow the traditional approach of hoisting the gaff horizontal. And only then top the gaff after the halyard is set up taut?  With these high-peaked gaffs, they're going to fight with the hoists and slides if the gaff is tried to be set up before the luff is taut.

Jon

[bruce]

Hey Jon, good to hear from another experienced catboat sailor.

I haven't tried to reproduce conditions that could lead to the pinching and bending of the extended ring by setting the peak before the throat is set and the luff taut, but I can assure you that on my boat, and on George Haycraft's that I posted photos of yesterday, and on Roger Shoemaker's that is shown in Jim's thread with the broken extended ring, we all raise the gaff roughly horizontal until the throat sets. We all also converted to 2:1 purchase on the throat, matching the peak halyard, so it's easy to haul on both together, keeping the gaff horizontal. The stock set up, with a 1:1 on the throat halyard requires extra care to keep the gaff horizontal, requiring hauling twice as much on the peak. Even then, I would expect the peak is usually lagging behind. Of course, there may be instances as you describe.

My boat was new in 2010, and I was aware of the binding problem from day one, from George, Roger, and others. I hadn't experienced any difficulty in raising the sail, but did note that my extend ring had bent to the side about 20º and the gaff had some scarring after a few sails. I replaced the stock extended ring slide with a Dwyer slide and soft shackle, with the ring oriented down, early on to prevent further damage.

[Roland of Macatawa]

Bruce,
Do you still have your added downhaul on the gaff gooseneck?
(After your suggestion, I added that gaff downhaul to my SunDayCat.)
How does your modified throat halyard pulling upward and the downhaul pulling downward work well together?
Seems like lines overlapping on the bottom side of the forward end of the gaff.
Thanks, Roland

[bruce]

Hey Roland, good to hear from you too!

I'm assuming you're looking at my rigging pictured in the last photo attached to Reply #7 in Jim's thread. Lots going on there, but you can make out the throat gooseneck slide with the ring on the bottom, the soft shackle that attaches to the throat halyard above the gaff, and, if you squint, you can see the downhaul attached to the same ring with a D shackle. The other end is made up at the base of the mast stub on the horn cleat where our stock boom downhaul is attached. We don't have a Spinlock cleat for the downhaul like the SC has.

I still have the gaff downhaul, it's actually good quality 1/4" bungee cord that is stretched to pretty much maximum as the throat is set. So, when the throat halyard is released, the first few feet at least come down quickly, after that some encouragement by hand on the luff may be necessary. Bungee only elongates about 50%, so it was only good for a few feet of spring back. I did experiment with UV-resistant rubber cord with more elongation, specifically Santoprene and EPDM, and, while the elongation was better, the return was slow and not very forceful.

I did remove the gaff downhaul after a couple of years just to see if I really felt it was useful. I decided it was worth keeping.

Most SC owners that I've heard have added a gaff downhaul use regular line, it doesn't need to be heavy. Then you can really bring the throat all the way down. I didn't want the extra cleat and line to store. The bungee is self-tending, and shorter when relaxed. The luff on any catboat is short, ours is about 9'.

[Jim in TC]

Hey Jon, good to hear from another experienced catboat sailor.

I haven't tried to reproduce conditions that could lead to the pinching and bending of the extended ring by setting the peak before the throat is set and the luff taut, but I can assure you that on my boat, and on George Haycraft's that I posted photos of yesterday, and on Roger Shoemaker's that is shown in Jim's thread with the broken extended ring, we all raise the gaff roughly horizontal until the throat sets. We all also converted to 2:1 purchase on the throat, matching the peak halyard, so it's easy to haul on both together, keeping the gaff horizontal. The stock set up, with a 1:1 on the throat halyard requires extra care to keep the gaff horizontal, requiring hauling twice as much on the peak. Even then, I would expect the peak is usually lagging behind. Of course, there may be instances as you describe.

I will pile on the "raising" issue to agree that keeping the gaff roughly horizontal is the way to go, and if it gets much "ahead" or "behind" I bring it back in line. I have not changed the purchase, though can see the advantage. But taking care and watching closely the 1:1 has not been particularly problematic. Typically, I am raising the throat halyard while the first mate raises the gaff. I pretty much simply watch both and maintain the the gaff going up more or less horizontal. When (rarely) single-handing, or breaking in a different sailor it becomes a little trickier but still, mostly, a matter of paying close attention and adjusting for the conditions. 

[bruce]

Jim,

I recall you replaced your gaff gooseneck entirely to fix the problems you were having in 2018. Looking at the photo of your new gooseneck, from Com-Pac, in Reply #22 of your thread I see you have the extended ring slide. How has that worked out, any bending or scarring on the gaff?

In the photo I see the red throat halyard but I don't see the ring. The top of my slide to the bottom of the ring is 1 9/16" (between the arrows in the photo). It looks like yours may be more, could you check that? If Com-Pac uses a longer stalk these days that may have corrected the problem. McNemo has a 2014, and he found scarring and his extended ring broke right off, but later boats, and current spare parts, may be OK.

Com-Pac lists the same part for all the catboats, MC00G000, $96.20.

[McNemo]

I'll be reaching out to see about a replacement, but I agree this wont keep me off the water. The humorous part of all this is modern technology has created more problems than it solves... on my traditional boat this would just be another fun splicing job. 

I am curious about the idea of mounting the piece upside down so that the ring is below the gooseneck. I am not an engineer but I would imagine there would be a lower failure rate with pressure being applied from underneath, with a ring affixed closer to the joint than the factory installed examples.

Thank you to the brain-trust for your wisdom!

[bruce]

The failure of the extended ring has nothing to do with the load experienced in raising the sail. Even if you tension the luff like a guitar string what are we talking, 1:1 purchase, no winch, 50 lbs? 1/4" SS rod has a much higher tensile strength than the 5/16" or 3/8" double braid that you might be using for a halyard, and both are overkill rated at thousands of pounds. The extended ring failure is due to metal fatigue as it is regularly flexed and bent when pinched between the gaff and mast as you sail. Bending a short length of 1/4" rod to failure is not easy!

I have aluminum adhered to my extended ring from galling on the gaff, further evidence of rubbing under very high pressure.