26S swing keel pivot assembly mystery copper sleeve

Nov 8, 2014
151
MacGregor 26S Chateauguay
Question for Sumner or anyone who has serviced the swing keel of a 26S
Thanks to Sumner's detailed pictorial instructions, I successfully managed to remove the keel for badly needed maintenance. The strange thing is that the po wrapped the pivot with electrical tape an then slipped a larger copper sleeve over it to fit the hole in the keel ( see pictures). Does this make sense? (Ignoring the electrical tape) .
Th hole in the keel is 1/2", that of the sleeve is 1 1/4" OD. Given that combining two metals in a wet environment doesn't make sense, I must assume that this is a fix by the PO. Should I less than the diameter of the hole with west epoxy and silica? Or you have other suggestions?
 

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walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
I think a PO probably modified the centerboard with that copper sleeve as I dont think they were manufactured that way. Was the copper sleeve epoxied into the centerboard pivot hole?

The main thing about that centerboard is that it there must be some play between the centerboard sleeve and the support pin as the centerboard gets its strength in the slot by contacting the sides of the slot so it must be able to rotate some. That pin just keeps the centerboard from falling out when the centerboard is not loaded. The pin itself should not carry the rotation load of the centerboard. In other words, it should be a fairly sloppy fit between the pin and the sleeve. As long as the fit is sloppy,what the PO did was probably fine..

Electrical tape.. dont know about that of why. Maybe it was to cut down noise at anchor with the centerboard down but still allow the centerboard to rotate a little in the slot????
 
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Nov 8, 2014
151
MacGregor 26S Chateauguay
Hi Walt, no the sleeve was lose, the purpose of the tape was to tighten the fit between the pivot and the copper sleeve. Interesting the idea of using the sides to apply force, it makes sense however, just how big should the difference be between the pivots OD and the sleeve hole in the board. Presently this difference is about 1/2 " or 1/4" around. It would be interesting to find out how big was the original hole.
 
Jun 25, 2016
65
Venture 21 Minter Bay
Hmmmm...on my '74 Venture 21 swing keel, there was a brass tube fit into the keel which I believed to be for a bearing surface for the pivot bolt (stainless). This boat has no metal support in the glass trunk for the pivot bolt (although I am considering adding something to prevent wear on that support point). The electrical tape might have been an effort to isolate to bolt to prevent corrosion...but that doesn't sound like a factory solution to me.

I'm looking forward to seeing your final solution. Cheers!
 
Nov 8, 2014
151
MacGregor 26S Chateauguay
Hmmmm...on my '74 Venture 21 swing keel, there was a brass tube fit into the keel which I believed to be for a bearing surface for the pivot bolt (stainless). This boat has no metal support in the glass trunk for the pivot bolt (although I am considering adding something to prevent wear on that support point). The electrical tape might have been an effort to isolate to bolt to prevent corrosion...but that doesn't sound like a factory solution to me.
I'm looking forward to seeing your final solution. Cheers!
The brass sleeve was indeed used as a bearing, brass is a traditional material for that application. The tape may have been used as an insulator as you suggest except it couldn't withstand the friction and was mostly torn off. In any case, I've always felt the POs sailed in mostly fresh water environments and that explains the lack of pitting on the brass or on the SS pivot. Since I intend sailing Egret in both salt and sweet water, I will probably build up the hole with a resin and silica putty while leaving abt. 1/8" space around the pivot to allow for the motion suggested by Walt. According to ruddercraft the hole size is 1 1/4", I must assume that is the blueprint size. Once I reach my final decision I will most certainly post it here. Meanwhile I have to rebuild the trailer...
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Is the tape intended to isolate the two metals from one another for galvanic corrosion protection?
 
Nov 8, 2014
151
MacGregor 26S Chateauguay
I'm not sure... If that was the POs intention it wouldn't work unless he found a way to isolate the SS supports as well. I think he wanted to snug up the fit or reduce the noise, I'm not sure, either way it was a bit of poor engineering :)
 
Nov 30, 2015
217
MacGregor 26S Lakehills, Tx
I'm not sure... If that was the POs intention it wouldn't work unless he found a way to isolate the SS supports as well. I think he wanted to snug up the fit or reduce the noise, I'm not sure, either way it was a bit of poor engineering :)
Not knowing the PO's real intention, I would say that this is the best guess. When I dropped "Mistress's" centerboard, I was contemplating methods of "tightening it" up. My thoughts centered around using a PVC bushing over the S/S pivot bushing so there wouldn't be any galvanic corrosion.
Realizing that the Mac centreboard is designed to be loose fitting, I ended up using 1/2" thick rubber washers between the CB and the mounting brackets. The rubber washers compress enough to put and end to the CB bump noise when at anchor while still allowing the CB to ride against the CB casing as designed.
 
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Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
...The rubber washers compress enough to put and end to the CB bump noise when at anchor while still allowing the CB to ride against the CB casing as designed.
Curious, do you raise the centerboard while anchored?

I guess I'm kind of paranoid about the boat swinging on anchor and the centerboard striking something from the side where it wouldn't be able to swing up....

http://purplesagetradingpost.com/sumner/Macgregor Trips-2-Priest/08-09-14-priest-koot.html

....... Since I anchor with it up I've never heard the centerboard hitting the hull. Also after the bottom paint on the board and inside the trunk that also made for a tighter fit while up.

Sumner
==============================================================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...

MacGregor 26-S Mods...http://purplesagetradingpost.com/sumner/endeavour-main/endeavour-index.html
Mac Trips to Utah, Idaho, Wyoming, Canada, Florida, Bahamas
 
Nov 30, 2015
217
MacGregor 26S Lakehills, Tx
That sounds like a great idea, thank you! Where did you buy the washers?
I bought them at Lowe's Home Improvement. They're in the Specialty items bins. Look for the rubber grommets. You'll have to bore them out to get the proper I.D.
 
Nov 30, 2015
217
MacGregor 26S Lakehills, Tx
Curious, do you raise the centerboard while anchored?

I guess I'm kind of paranoid about the boat swinging on anchor and the centerboard striking something from the side where it wouldn't be able to swing up....

http://purplesagetradingpost.com/sumner/Macgregor Trips-2-Priest/08-09-14-priest-koot.html

....... Since I anchor with it up I've never heard the centerboard hitting the hull. Also after the bottom paint on the board and inside the trunk that also made for a tighter fit while up.

Sumner
In the two years that I've had "Mistress", we've only anchored in water that is deeper than the CB when it is down. It helps negate the rocking from wave action caused by ********* jet skiers and stink-boaters who enjoy roaring through an anchorage. The local lake bottom is rocky, and I don't want to chance putting a hole in the hull by dropping anchor in shallow water .
The rubber washers do a great job at their intended purpose, and don't notice much more pulling force needed to raise the CB. It also drops easily without any binding.
How long will they last in a marine environment before needing to be changed? I don't know.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
I made grommets out of nylon rod. They buffered the keel and didn’t show any wear after 8 years.
 
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Nov 30, 2015
217
MacGregor 26S Lakehills, Tx

This is the CB that was on "Mistress" when I bought her. I presumed that it was original to the boat. The leading edge was scraped badly, and the trailing edge was split nearly 18". That white line at the top of the board was where the PO had the uphaul line wrapped around the board and basically tied with a granny knot.
The pivot hole is a lot smaller in diameter than on the new CB I bought to replace this one after it dropped between the rear trailer crossmember and the ramp, necessitating the cut to get "Mistress" out of the water before a storm blew in.



This is the new CB from Defender Marine. As you can see, the pivot hole is larger, and the notch by the hole on the trailing edge is where the up-haul line is attached. It is still not a tight fit.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
I hated the banging. Hated with a capital h. The project was aimed at getting the cavity snugged up, without binding. The “washer” part wasn’t all that big, as I recall, cuz if you look up in there while the boats on the trailer, you’ll see that the trunk is already tapering at the bolt. Above it, things get tight rather quick.
Part of the project also involved a sleeve that the bolt fit through, that fit in the hole in the water tank, not so much to seal it, but to take the play out of the bolt.
 

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
.....



This is the new CB from Defender Marine. ..
That looks like a Rudder Craft center board....



... like ours shown above and ...



... above is where the uphaul locates. Looks the same....

http://purplesagetradingpost.com/sumner/macgregor2/outside-40.html

Sumner
====================================================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...

MacGregor 26-S Mods...http://purplesagetradingpost.com/sumner/endeavour-main/endeavour-index.html
Mac Trips to Utah, Idaho, Wyoming, Canada, Florida, Bahamas
 
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Nov 8, 2014
151
MacGregor 26S Chateauguay
In my case only if the line is not tight. If I cleat it in tight I have no problems but if it's just a little bit loose then I hear that very annoying banging. Not allMacs are created equal