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OEM Rudder 85 sk

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yachtsea
1st Mate

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73 Posts

Initially Posted - 03/16/2019 : 08:01:11

Ahoy,

I removed the anti-fouling paint from my rudder (85/sk) this season and I'm inspecting to see if it is worth taking down gel coat or barrier coat (whatever this is, please comment) for every single blister and building it back up. I don't think I see an area yet that warrants cloth, just colloidal silica, West 406, and then some epoxy resin and hardener; West 105 and 205, respectively. Then I suppose some gel coat or barrier paint, of which I have not dabbled in either before. Finally, anti-fouling.

I put a shared album up here for review:
https://photos.app.goo.gl/9wGCNL1niCQrgw4e8
Now that I am looking at it, that's a lot of small blisters. Is this negligible and simply use until it's obvious to undertake major repair or is this easier tackled now with weeks until haul in? I read, once exposed, that it takes many weeks for these blisters to completely dry and if not done, the repair effort is futile. It almost seems like, by the time I finished, I would be looking for a professional dip.

Also hoping to learn if anyone knows the weight of the OEM 65.5" sk rudder (not the 80" on CD). Mine is coming in just under 28lbs. including the pintle hardware. To me, that doesn't seem excessive so I do not think it is waterlogged. It's been off the boat and in my climate-controlled basement since October. I'm in WI and she moors from May to October in a small freshwater lake (6000 acres).

Thanks much,

Carl

Steve Milby
Past Commodore

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5851 Posts

Response Posted - 03/16/2019 : 08:35:07

It's always hard to tell from photos, but I don't see any blisters. I see a few minute chips in the gel coat. Blisters look like raised bumps in the gel coat, and, if you pierce them, a little water comes out. You don't want to apply barrier coat over those blisters because you'd be permanently enclosing that moisture. If it has been in a heated area since October and has no water-filled blisters, it's probably dry.

It's a judgment call whether you apply barrier coat. Across the boat building industry, the highest incidence of blisters was between about 1984 or 85 and 1989. After 1989 the problem became much rarer. If you have none, you're lucky. I think I'd apply about 4 coats of barrier paint, and then finish it off with a couple coats of white antifouling paint. You might also put an extra barrier coat or two just over the small spots where the gel coat is chipped down to the fiberglass, just to be sure it's sealed.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Edited by - Steve Milby on 03/16/2019 08:41:54

Voyager
Master Marine Consultant

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5231 Posts

Response Posted - 03/16/2019 : 08:42:12

Hi Carl, I just took a look at the photos. You have a few things you can do depending on how "perfect" you want it.
For checking on waterlogged core, use a moisture meter or drill a few test holes to check the core. You can fill them later with Marine Tex if they�re dry. If wet, you have a few options, but it�s mostly major surgery.

If dry, regarding the finish here are some options :
1. You can ignore the tiny blisters now that it�s had a season to dry, but once back in the water they will grow again. If you decide to ignore them, you can use Marine Tex to repair the small chips and holes. Use enough material to make them slightly raised, then sand once cured to flatten the patches. The color is pretty close to our boats� color, or you can tint slightly. You can dry or wet sand the whole thing with 400 grit to remove the top layer of stained gelcoat, then either wax, Polyglo or paint with 1 part or 2 part polyurethane paint to finish the exterior.

2. If you go that far, you might as well pop the blisters and fill with thickened epoxy or Marine Tex. Then sand everything and use a light coat of fairing compound to smooth everything. Then get you barrier coat and do 6-8 coats. Make sure to heed the instructions - you must not let barrier coat completely cure before doing the next coat.
Then paint with 1 or 2 part polyurethane paint. Or you could gelcoat, but that�s a little harder to get right.

Bruce Ross
Passage ~ SR-FK ~ C25 #5032

Port Captain � Milford, CT

Voyager
Master Marine Consultant

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5231 Posts

Response Posted - 03/16/2019 : 08:48:51

@ Steve Milby, you can see a shipload of small blisters in photo # 3 and # 4 in the reflection of the flash.
I�m using my iPad 4 mini, maybe they�re too small to see on a phone?

Bruce Ross
Passage ~ SR-FK ~ C25 #5032

Port Captain � Milford, CT

Edited by - Voyager on 03/16/2019 08:51:35

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 03/16/2019 : 09:05:47

What I think I see are popped, tiny gelcoat blisters--nothing obvious in the laminate. This is to be expected, especially in fresh water. I would open up any others that haven't already popped, and smooth with a little Marine Tex (epoxy putty), and then sand and barrier coat the whole blade (if I were serious about keeping that rudder)...

The original rudder on the '85 (and all earlier years) is solid glass below the waterline; the thicker "head" is wood-cored. That head is the most worrisome part--if the core has become wet from the various bolt holes and/or cracks (like a split between the two sides), it will be weakened at the most critical area--around the lower pintle. That's where, under stress, many have broken clean off--a nasty surprise at a difficult time. I replaced mine soon after buying the then-15-year-old boat, choosing the foam-cored fiberglass "balanced" rudder I believe CD still sells, which became the OEM rudder around 1987-8 and thereafter. "Balanced" means it has some area forward of the pivot line described by the pintles, creating something like power steering. Indeed, even going to windward with some significant weather helm (such that if you release the tiller the boat rounds up rapidly), it's still finger-tip steering. Others here have done this upgrade, and I think they all were happy with it. Just a thought...

(BTW, I have yet to hear of one of those foam-cored rudders breaking, although I have heard of some after-market HDPE rudders snapping. I think the maker of the HDPE models increased their thickness a few years back.)

EDIT: I just looked at CD's rudders and the fiberglass one has been redesigned to replace the foam with a fiberglass skeleton.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 03/18/2019 06:25:14

Steve Milby
Past Commodore

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5851 Posts

Response Posted - 03/16/2019 : 09:47:23

quote:
Originally posted by Voyager

@ Steve Milby, you can see a shipload of small blisters in photo # 3 and # 4 in the reflection of the flash.
I�m using my iPad 4 mini, maybe they�re too small to see on a phone?

You're right. They're so tiny I didn't see them until I enlarged the photo to the max. Nevertheless, they're superficial. I'd scrape the surface off them, dry them a few days fill them with a little Marine Tex, barrier coat it and paint it with antifouling.

There's a fairly wide range of opinions about blisters. In the 1980s people were terrified of them. Now some still take them very seriously, but many people (other than racers who want the surface perfect) think they're mostly cosmetic, ignore them and keep painting over them with antifouling. I'm in the middle. I clean them out, dry them out, fill them, barrier coat them (if they are numerous) and apply antifouling paint. I've owned fiberglass boats since about 1978, and have treated blisters on all my boats the same way, and never had a major problem or a recurrence.

There are rare instances where blisters justify serious remedial action, but this rudder looks very superficial.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

yachtsea
1st Mate

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USA
73 Posts

Response Posted - 03/16/2019 : 12:05:07

Steve, Bruce, Dave,

I'm overwhelmed. I step out to fetch a whisker pole (which of course turned into cleaning the garage) and I come back to this! Thanks all. Although aware, first time I have looked into barrier paint with a specific application in mind. I watched some videos on the overcoat while still tacky; less, you will need to sand.

I have Marine Tex and that is what I originally set out to use but after watching a few videos and some light reading, that's what prompted this question. Now reflecting on all of that information including your contributions, I think the aversion to Marine Tex was due to more significant infiltration than what I have so they (not yous) were concerned with maintaining structural integrity. I don't think my rudder's strength is compromised at all.

As suggested, in an effort to see if any residual moisture was behind these blisters, I popped a few, quite a few, with an Xacto knife. An audible "click" indicating penetration into a void was clear but not one leaked. I suspect that with hundreds of these things, that's evidence moisture is already behind but now I'm reconsidering for this season, would it be better to leave as is and plan better for next offseason or am I committed now to resealing the popping I've accomplished?

Dave, I was on CD as mentioned earlier navigating their new site and found an 80inch rudder which I don't believe is designed for the swing keel (65.5). I did read some that OEM rudders were subject to being overpowered (which we have experienced) and that ever-sought-after fingertip pressure to steer is available on the upgrade for 1000-1200 dollars. I believe that HDPE. I do not recall seeing one that matched the description you had. Would you have a link (if that is permissible in this forum)?

Thanks again,

Carl

Steve Milby
Past Commodore

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5851 Posts

Response Posted - 03/16/2019 : 14:49:16

Carl, when I bought my C25 new in 1981, the C25 had a reputation for having a very heavy weather helm. I learned that its heavy helm was due to poor rig tuning.

A sailboat is designed so that its central axis runs down the mast and approximately through the center of lateral resistance (CLR), which is located approximately in the center of the keel.

When the wind pushes on the mainsail, the pressure on the mainsail pushes the stern of the boat to leeward. When the wind pushes on a 100% jib, the pressure on the jib pushes the bow of the boat to leeward. When those pressures are in balance, then the boat will have a neutral helm.

This balance can be upset by the way you adjust your mast. If the mast is tilted too far forward, it will increase the pressure on the jib and decrease pressure on the mainsail, and that will cause a lee helm. If the mast is tilted too far aft, it will increase the pressure on the mainsail and decrease pressure on the jib, and that will cause increased weather helm. Thus, the first step toward finding a lightly balanced helm is to adjust the fore/aft rake of the mast correctly.

My approach with any boat is to set up the mast so that it's plumb. Then I sail it, and pay attention to how the helm feels sailing to windward in about 10 kts wind. Usually it will have too light weather helm, so I'll tilt it back an inch or two and sail it again and see how it feels. I usually find a nice, light helm with the mast of a 25' boat raked aft at somewhere between 1-2".

After you have tuned the mast correctly, let's talk about what happens when you raise an overlapping jib. An overlapping jib doesn't add any more sail area forward of the CLR, but it does add sail area aft of the CLR. That creates more pressure on the overall sailplan aft of the CLR, and that increases weather helm. You'll have to pull a little harder on the tiller to hold the boats bow off the wind. The way you restore that light, balanced helm is by easing the mainsheet traveler to leeward, not enough to luff the mainsail, but enough to restore a light feel to the tiller. That reduces pressure on the sail area that is aft of the CLR.

You might think that easing the main traveler would reduce boat speed, but it actually has the opposite effect. When you feel heavy tiller pressure, that means you have to turn the rudder to prevent the boat from heading to windward. Anytime you turn the rudder, you're creating drag and slowing the boat. Easing the traveler to leeward reduces drag, increases speed, and the increased speed lets the boat point higher.

My suggestion is that you tune your rig correctly before you spend over $1000. for a new rudder. You might find, as I did with my C25, that you really don't need it to achieve a light helm. With its original, non-balanced rudder, my 25 had a very light helm, and when the wind piped up, its helm remained light simply by easing the traveler to leeward to maintain the balance between the pressures on the sails and the CLR.

The main underlying cause of a heavy helm on a C25 is a poorly tuned rig. A secondary cause is poor helmsmanship. When the wind pipes up, people tend to pull harder on the tiller. That drags the rudder sideways through the water, slowing the boat, and it makes you arm weary. Instead, you should not only ease the traveler, but also ease your pressure on the tiller. That allows the boat to run more freely and reduces drag. Just hold the tiller a few degrees off from the centerline of the boat. I watched a friend pulling his tiller until his hand almost touched the windward seat, and he couldn't understand why the boat was slow and wouldn't point.

(I edited this reply to eliminate references to the C250. I was thinking about a thread currently in the C250 forum in which the owner was asking about the 2nd generation rudder.)

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Edited by - Steve Milby on 03/17/2019 05:52:08

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 03/16/2019 : 21:10:43

quote:
Originally posted by yachtsea

...I do not recall seeing one that matched the description you had. Would you have a link (if that is permissible in this forum)?

It certainly is permissible... Here it is. It's not cheap, but compared to the "excitement" of a broken rudder in a blow, I'd call it a good investment. It might be a better product than what I bought. I recall that even one of our most decorated racers loved the version I had. IMHO, the rudder comes in second only to the mast, or maybe after the keel, as the most critical component of a sailboat. And this design is a significant improvement over the original--to the point that Catalina switched to the foam cored version (where this might be an improvement). Let's just say I'm in favor of the upgrade--I consider it a safety and security issue.

If you're interested, I would talk to CD about getting it without the pintles installed, just because the exact gudgeon placement on every C-25 hull might vary a little.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 03/16/2019 21:18:28

Voyager
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5231 Posts

Response Posted - 03/17/2019 : 06:53:30

@ Carl Yachtsea � sorry for the overwhelm.
Perhaps there�s a simpler approach. You could buy a new rudder (Dave �Stinkpotter� knows a beautiful rudder when he sees one) or you can take the following tack with your current rudder if you believe it is structurally sound.

You said that the blisters are small and dry. Take your palm or orbital sander with 100 grit plus your vacuum attachment and put on your goggles and respirator and smooth down the rudder.

Scratch the surface. The blisters will open up, ridding you of that problem.

You could fill the larger voids with Marine Tex or fair the entire rudder with fairing compound (the rudder is a pretty small job as fairing goes). Then cover with barrier coat. Then apply topside paint above waterline and bottom paint below. Finito!

Bruce Ross
Passage ~ SR-FK ~ C25 #5032

Port Captain � Milford, CT

Edited by - Voyager on 03/17/2019 06:58:46

yachtsea
1st Mate

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USA
73 Posts

Response Posted - 03/17/2019 : 07:58:52

I have some good options here. Thank you. While I'm a fan of optimization and this will be a valid test of my familiarization with Anodyne's rigging, I like the idea of innovation too. My least personal confidence is in refairing the entire rudder's surface without influencing hydrodynamics adversely. Not that I'm cruising but we do plan to take her out of Bayfield and onto Lake Michigan for a week at a time. I also like the idea of demoting the OEM to the spares' bin. My current plan (open to ridicule/correction) is to take the blisters down, repair the light damage around the pintles, fill with MarineTex, sand fair (yay 1990s' USMC helicopter airframes experience becoming relevant) and throw several coats of barrier paint at it followed by anti-fouling paint that came with her to match the hull. I'll then add the tuning information to this year's applied knowledge and re-evaluate.

I hope our paths cross again soon. Anodyne is in good condition. My chief concern, safety-wise, is the hinge pin. The previous owner (who was also on this forum) had access to a sling and said he inspected the hinge pin for play circa 2016. I replaced the winch, which dropped the keel onto the trailer on purchase day, but the cable and turning ball were new. I've looked around for options ranging from blocks (lots of opinions on whether or not a retracted swing keel should support a boat like a fixed keel, my opinion is no)...from blocks and stands to Go-Hoist.com's portable sling, to taking it to a proper marina and having the hardware replaced with a bottom job. That last one would pay for reusable equipment but my driveway has a slope to it and I wonder how much she would swing once the weight was off the trailer.

But that's another topic. https://photos.app.goo.gl/CsJng1nxuqxycwBZ2

Cheers,

Carl

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 03/17/2019 : 12:09:45

quote:
Originally posted by yachtsea

...(lots of opinions on whether or not a retracted swing keel should support a boat like a fixed keel, my opinion is no)

You are correct, sir!

A fin keel C-25 can rest on its keel, with other supports holding it upright. If the swing keel boat were to rest on the raised keel, especially on a trailer moving down the road, the keel could seriously damage the trunk. It's also not advised to have the keel hanging from its cable when trailered or stored on the hard--it's meant to be lowered at least somewhat onto a support (block or whatever) so the cable and winch aren't supporting it, and then cranked back up for launching.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Erik Cornelison
Navigator

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USA
194 Posts

Response Posted - 03/17/2019 : 14:41:31

Can you tell me if that applies to a 1986 Catalina 25, the rudder being solid? When was the cut off or year change?

Erik

quote:
Originally posted by Stinkpotter

What I think I see are popped, tiny gelcoat blisters--nothing obvious in the laminate. This is to be expected, especially in fresh water. I would open up any others that haven't already popped, and smooth with a little Marine Tex (epoxy putty), and then sand and barrier coat the whole blade (if I were serious about keeping that rudder)...

The original rudder on the '85 (and all earlier years) is solid glass below the waterline; the thicker "head" is wood-cored. That head is the most worrisome part--if the core has become wet from the various bolt holes and/or cracks (like a split between the two sides), it will be weakened at the most critical area--around the lower pintle. That's where, under stress, many have broken clean off--a nasty surprise at a difficult time. I replaced mine soon after buying the then-15-year-old boat, choosing the foam-cored fiberglass "balanced" rudder I believe CD still sells, which became the OEM rudder around 1987-8 and thereafter. "Balanced" means it has some area forward of the pivot line described by the pintles, creating something like power steering. Indeed, even going to windward with some significant weather helm (such that if you release the tiller the boat rounds up rapidly), it's still finger-tip steering. Others here have done this upgrade, and I think they all were happy with it. Just a thought...

(BTW, I have yet to hear of one of those foam-cored rudders breaking, although I have heard of some after-market HDPE rudders snapping. I think the maker of the HDPE models increased there thickness a few years back.)

EDIT: I just looked at CD's rudders and the fiberglass one has been redesigned to replace the foam with a fiberglass skeleton.

Erik Cornelison
6th Generation Professional Sailor, First Gen Submarine Sailor.
1986 Standard Rig SW. #5234

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 03/17/2019 : 19:55:24

quote:
Originally posted by Erik Cornelison

Can you tell me if that applies to a 1986 Catalina 25, the rudder being solid? When was the cut off or year change?

I think the change was during the 1987 model year, or maybe 1988, but others with those vintages can correct me. All 1989-91s had it.

If your rudder has the shape below, with the steps projecting forward under the pintles and a rounded forward edge (as on a NACA foil), it's the newer version.

If the aft edge is perfectly straight and the forward edge is fairly sharp, it's the original design from 1976.
[/quote]

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 03/17/2019 20:00:30

cudamank
1st Mate

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USA
55 Posts

Response Posted - 03/28/2019 : 16:34:46

What are the best ways to dry out a rudder before beginning repairs?

1982 Catalina 25 SR FK
"Jenny"

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Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.